WO1997017083A1

WO1997017083A1 - Method for treating obesity and type ii diabetes by adjusting the circadian rhythm of human growth hormone

Info

Publication number: WO1997017083A1
Application number: PCT/US1996/018415
Authority: WO
Inventors: Anthony H. Cincotta
Original assignee: Ergo Science Incorporated
Priority date: 1995-11-09
Filing date: 1996-11-08
Publication date: 1997-05-15

Abstract

The invention relates to methods for the regulation in a vertebrate animal or human subject of at least one of lipid and glucose metabolism by the daily administration of growth hormone at a predetermined time of day. More specifically, this invention relates to methods for the improvement of one or more metabolic indices associated with lipid and glucose metabolism disorders, especially those associated with Type II diabetes, also known as non-insulin dependent diabetes mellitus (NIDDM), whereby the improvements persist over an extended period of time after cessation of treatment, wherein the method comprises the daily administration of growth hormone at a predetermined time of day. These indices include body fat stores, hyperlipoproteinemia, hypertriglyceridemia, insulin resistance, hyperinsulinemia, and hyperglycemia.

Description

METHOD FOR TREATING OBESITY AND TYPE II DIABETES

BY ADJUSTING THE CIRCADIAN RHYTHM OF HUMAN GROWTH HORMONE

This application claims priority pursuant to 35 U.S.C. § 119 from provisional application Serial No. 60/007,338, the disclosure of which is incoiporated herein by reference in its entirety.

FIELD OF THE INVENTION

This invention relates to regulation in a vertebrate animal or human subject of at least one of lipid and glucose metabolism. More specifically, this invention relates to methods for the improvement of one or more metabolic indices associated with lipid and glucose metabolism disorders, especially those associated with Type π diabetes, also known as non-insulin dependent diabetes mellitus (NIDDM), whereby the improvements persist over an extended period of time after cessation of treatment. These indices include body fat stores, hyperlipoprotememia and hypertriglyceridemia, insulin resistance, hyperinsulinemia, and hyperglycemia.

In particular the present invention is directed to methods for: (i) adjusting aberrant daily growth hormone rhythms in a human or vertebrate animal and causing them to conform or approach those of a young, healthy member of the same species; and (ii) diagnosing aberrant daily growth hormone rhythms of a human or vertebrate animal; and determining the appropriate adjustments that need to be made to "normalize" such aberrant growth hormone rhythms. Such adjustments include the daily administration to the subject of growth hormone or a growth hormone enhancer at a predetermined time of day selected to increase blood levels of growth hormone during a time interval during sleeptime when growth hormone levels in young healthy individuals of the same species are high. This therapy typically results in the long-term adjustment (resetting) of aberrant or abnormal growth hormone rhythms so that they conform to or approach normal growth hormone cycles, at which point the therapy may be discontinued, while the adjustment persists. Resetting of the growth hormone rhythm will ameliorate one or more of the foregoing metabolic indices.

This invention is also directed to methods for adjusting the neural oscillator (or oscillators) of which the daily growth hormone rhythm is an expression or marker.

The adjustment of daily growth hormone rhythms and the daily rhythms of key neural oscillators results in reduction and control over an extended time period of various metabolic or other disorders.

BACKGROUND OF THE INVENTION

Obesity and Other Lipid Metabolism Disorders Bodv Fat Stores

In humans obesity can be defined as a body weight exceeding 20% of the desirable body weight for individuals of the same sex, height and frame (Salans, L.B. , in Endocrinology & Metabolism. 2d Ed., McGraw-Hill, New York 1987, pp. 1203-1244; see also. R.H. Williams, Textbook of Endocrinology. 1974, pp. 904-916). In other animals (or also in humans) obesity can be determined by body weight patterns correlated with growth hormone profiles given that members of a species that are young, lean and "healthy" (i.e., free of any disorders, not just metabolic disorders) have daily plasma growth hormone level profiles that follow a regular pattern with little or no standard deviation. A typical growth hormone profile of healthy human subjects is shown in Figure 1.

Obesity, or excess fat deposits, correlate with and may trigger the onset of various lipid metabolism disorders, e.g. hypertension, Type II diabetes, atherosclerosis, etc.

Even in the absence of clinical obesity (according to the above definition) the reduction of body fat stores (notably visceral fat stores) in man, especially on a long- term or permanent basis, would be of significant benefit, both cosmetically and physiologically. The reduction of body fat stores in domestic animals (as well as pets) especially on a long-term or permanent basis would also obviously be of considerable economic benefit to man, particularly since farm animals supply a major portion of man's diet; and the animal fat may end up as de novo fat deposits in man. Whereas controlled diet and exercise can produce modest results in the reduction of body fat deposits, prior to the cumulative work of the present inventors (including the prior co-pending patent applications and issued U.S. patents referred to below), no truly effective or practical treatment had been found for controlling obesity or other lipid metabolism disorders. Hyperlipoproteinemia is a condition in which the concentration of one or more of cholesterol- or triglyceride-carrying lipoproteins (such as chylomicrons, very low density lipoproteins or VLDL and low-density lipoproteins or LDL) in plasma exceeds a normal limit. This upper limit is generally defined as the ninety-fifth percentile of a random population. Elevated levels of these substances have also been positively correlated with atherosclerosis and the often resulting cardiac infarction, or "heart attack" , which accounts for approximately one-half of all deaths in the United States. Strong clinical evidence has been presented which correlates a reduction in plasma lipoprotein concentration with a reduced risk of atherosclerosis (Noma, A., et al. , Atherosclerosis 42:1, 1983; Illingworth, D. and Conner, W., in Endocrinology & Metabolism. McGraw- Hill, New York 1987). Thus, a significant amount of research has been devoted to finding treatment methods which reduce levels of plasma cholesterol and triglycerides.

Another subset of the plasma lipoproteins found in vertebrates are high density lipoproteins, or HDL. HDL serve to remove free cholesterol from the plasma. A high HDL concentration as a percentage of total plasma cholesterol has been associated with a reduced risk of atherosclerosis and heart disease. Thus HDL are known in the lay press as "good" cholesterol. Therefore, therapeutic strategies involve attempts both to reduce plasma LDL and VLDL content (that is, reduce total plasma cholesterol), and to increase the HDL fraction of total plasma cholesterol. Several lines of research indicate that simply increasing HDL is of benefit even in the absence of LDL or VLDL reduction: Bell, G.P. et al., Atherosclerosis 26:47-54, 1980; Fears, R. , Biochem. Pharmacol. 21:219-228, 1984; Thompson, G., Br. Heart J. 11:585-588, 1989; Blackburn, H. N.E.J.M. 209:426-428, 1983. Current therapies for hyperlipoproteinemia include a low fat diet and elimination of aggravating factors such as sedentary lifestyle. If the hyperlipoproteinemia is secondary (i.e. incident to e.g. a deficiency of lipoprotein lipase or LDL receptor, various endocrine pathologies, alcoholism, renal disorders, hepatic disorders) then control of the underlying disease is also central to treatment. Hyperlipoproteinemias are also treated with drugs, which usually alter the levels of particular components of the total plasma cholesterol, as well as reduce the total plasma lipid component. Among the recently introduced drugs to treat hyperlipoproteinemia is lovastatin (MEVACOR^®) which selectively inhibits an enzyme involved in cholesterol production, 3-hydroxy-3-methylglut- aryl coenzyme A (HMG-CoA) reductase. This drug specifically reduces total cholesterol and can cause a modest (5-10%) increase in HDL concentrations. However, benefits from these therapies vary from subject to subject.

Moreover, use of the HMG-CoA enzyme inhibitor is sometimes accompanied by side effects such as liver toxicity, renal myoglobinuria, renal shutdown, and lenticular opacity. The risk of such side effects necessitates close momtoring of the patients (e.g. , liver function is tested monthly).

Another drug prescribed against hyperlipoproteinemia is clofibrate. The effectiveness of clofibrate also varies from subject to subject and its use is often accompanied by such side effects as nephrotic syndromes, increased incidence of gallbladder disease, myalgia, nausea and abdominal pain.

Hypertriglyceridemia is a condition where triglyceride levels in a subject are elevated relative to the triglyceride levels found lean, healthy subjects of the same species. In humans, a serum triglyceride value of higher than 140 mg/100 ml is considered abnormally high. Current pharmaceutical therapies for hypertriglyceridemia include clofibrate and a structural relative, gemfibrozil. The side effects of gemfibrozil are similar to those of clofibrate. Diabetes

Diabetes, one of the most insidious of the major diseases, can strike suddenly or lie undiagnosed for years while attacking the blood vessels and nerves. Diabetics, as a group, are far more often afflicted with blindness, heart disease, stroke, kidney disease, hearing loss, gangrene and impotence. One third of all visits to physicians are occasioned by this disease and its complications, and diabetes and its complications are a leading cause of untimely death in the United States and in the Western world. Diabetes adversely affects the way the body uses sugars and starches which, during digestion, are converted into glucose. Insulin, a hormone produced by the pancreas, makes the glucose available to the body's cells for energy. In muscle, adipose (fat) and connective tissues, insulin facilitates the entry of glucose into the cells by an action on the cell membranes. The ingested glucose is normally converted in the liver to CO₂ and H₂O (50%); to glycogen (5%); and to fat (30-40%), the latter being stored in fat depots. Fatty acids from the adipose tissues are circulated, returned to the liver for re- synthesis of triacylglycerol and metabolized to ketone bodies for utilization by the tissues. The fatty acids are also metabolized by other organs. Fat formation is a major pathway for carbohydrate utilization.

The net effect of insulin is to promote the storage and use of carbohydrates, protein and fat. Insulin deficiency is a common and serious pathologic condition in man. In insulin-dependent (IDDM or Type I) diabetes the pancreas produces little or no insulin, and insulin must be injected daily for the survival of the diabetic. In noninsulin-dependent (NIDDM or Type II) diabetes the pancreas retains the ability to produce insulin and in fact may produce higher than normal amounts of insulin, but the amount of insulin is relatively insufficient, or less than fully effective, due to cellular resistance to insulin.

In either form of diabetes there are widespread abnormalities. In most NIDDM subjects, the fundamental defects to which the abnormalities can be traced are (1) a reduced entry of glucose into various "peripheral" tissues and (2) an increased liberation of glucose into the circulation from the liver. There is therefore an extracellular glucose excess and an intracellular glucose deficiency. There is also a decrease in the entry of amino acids into muscle and an increase in lipolysis. Hyperlipoproteinemia is also a common complication of NIDDM. The cumulative effect of these diabetes- associated abnormalities is severe blood vessel and nerve damage.

No effective treatment has been found for controlling either hyperinsu- linemia or insulin resistance prior to the cumulative work of the present inventors, (including the prior co-pending patent applications and issued U.S. patents referred to below). Hyperinsulinemia is a higher-than-normal level of insulin in the blood. Insulin resistance can be defined as a state in which a normal amount of insulin produces a subnormal biologic response. In insulin-treated patients with diabetes, insulin resistance is considered to be present whenever the therapeutic dose of insulin exceeds the secretory rate of insulin in normal persons. Insulin resistance is also associated with higher-than- normal levels of insulin i.e. hyperinsulinemia ~ when normal or elevated levels of blood glucose are present.

The principal unit of biological time measurement, the circadian or daily rhythm, is present at all levels of neuroendocrine organization. Daily rhythms have been reported for many hormones inclusive of the adrenal steroids, e.g. , the glucocortico¬ steroids, notably cortisol, melatonin, a hormone secreted by the pineal gland, and prolactin and growth hormone, hormones secreted by the pituitary.

In our prior co-pending patent application Serial No. 08/452,388 we have disclosed and claimed methods for regulating lipid metabolism disorders by administering prolactin (or both prolactin and a glucocorticosteroid ("GC")) into the bloodstream of an animal or human on a timed daily basis in an amount and for a period of time sufficient to modify and reset the neural phase oscillation of the prolactin daily rhythm which then increases insulin sensitivity. The prolactin (or prolactin and glucocorticosteroid) injections are timed to create a peak in the subject's daily prolactin (or both prolactin and glucocorticosteroid) profile that coincides in time with the peak prolactin (or prolactin and GC peaks, respectively) of a young, lean, insulin-sensitive and otherwise healthy human to increase insulin sensitivity and reduce body fat stores. Injections of the same agent(s) are timed towards the peak prolactin time of an obese subject to achieve fat gain, if desired. In our prior application Serial No. 07/719,745, now U.S. Patent No.

5,344,832, we have disclosed and claimed enhanced methods for modifying and resetting the neural phase oscillations of the brain which control prolactin levels comprising both (a) administering to the subject a dopamine agonist just after the time at which the normal prolactin profile peaks to reduce prolactin levels to the low "day" levels and (b) administering to the subject a prolactin enhancer at a time just before the prolactin level peaks in normal subjects with the objective of causing the subject's prolactin profile to mimic in shape and time the profile of a lean human not suffering from one or more of aforementioned metabolic disorders.

In co-pending application Ser. No. 07/995,292, now allowed, we have disclosed and claimed certain improved methods for diagnosing aberrant prolactin rhythms, determining adjustments to be made to abnormal prolactin rhythms, and normalizing abnormal prolactin rhythms. In co-pending application Serial No. 178,569, we disclose and claim a method of treating various lipid metabolism disorders involving the synergistic combination of diet and the administration of a prolactin inhibitor.

Thus, the present inventors have discovered and disclosed that normaliza- tion (complete normalization or partial normalization, i.e. decrease of the differences in phase and amplitude between the prolactin rhythm of a subject to be treated and the normal or healthy prolactin profile) of prolactin daily rhythms of subjects with abnormal prolactin daily rhythms can reduce obesity and significantly improve insulin sensitivity, as well as reduce hyperinsulinemia and hyperglycemia not just in immediate response to the treatment but throughout the course of the day and even on a long term basis. This normalization is accomplished by administration of prolactin inhibitors or enhancers on a timed daily basis, for a period of time long enough to reset the prolactin rhythms of afflicted subjects such that the normalization lasts for an extended period of time.

Now, however, the present inventors have made the entirely unexpected discovery that increasing growth hormone levels on a timed daily basis in individuals who are obese, and/or suffer from other lipid and/or glucose metabolism disorders such as NIDDM can reduce body fat deposits, hyperlipoproteinemia and/or hypertriglyceridemia and the indices of glucose metabolism disorders such as insulin resistance, hyperinsu¬ linemia, and hyperglycemia. This finding is unexpected because while it is well-known that administra¬ tion of growth hormone will cause an acute release of fatty acids from adipose tissue, there is no teaching in the prior art that administration of growth hormone or a growth hormone enhancer on a timed daily basis (predetermined to increase growth hormone levels during sleeptime) over an extended period of time will lead to reduced levels of body fat, which reductions can be maintained after the cessation of growth hormone or growth hormone enhancer administration. Administration of growth hormone on a "timed daily basis", as defined herein, has the following meaning: "Timed" means admmistration during a specific time interval of a 24 hour period, (said 24 hour period comprising a day), predetermined to increase growth hormone levels during sleeptime. "Daily" means every day, for a period of not less than 10 consecutive days.

Further, it is surprising that growth hormone or growth hormone enhancer administration on a timed daily basis has the effect of reducing symptoms of diabetes, such as insulin resistance, hyperinsulinemia, and hyperglycemia. This is because growth hormone has been described as a known diabetogenic hormone. Generally, increased growth hormone levels cause an acute increase in blood glucose concentration, probably as a result of the above-mentioned increased release of fatty acids from adipose tissue which leads to an increased availability of fatty acids to be used for energy; the increase in fatty acid availability reduces the usage of glucose for energy. The increase in blood glucose stimulates the beta cells of the islets of Langerhans in the pancreas to secrete extra insulin. In addition to this effect, growth hormone also has a slight direct stimulatory effect on the beta cells. The combination of these two effects sometimes so greatly over- stimulate insulin secretion by the beta cells that they literally "bum out". When too many beta cells "bum out", a person develops diabetes (Guyton, A.C., Textbook of Medical Physiology, (1986) 10th Ed., p. 888). Also, patients afflicted with acromegaly (caused by abnormally high growth hormone levels) are notoriously insulin resistant and often diabetic. Thus the methods of treatment claimed herein are completely suiprising, and contrary to the teaching of the art. Also not taught by the prior art is "timed daily administration" of growth hormone or a growth hormone enhancer as we define it above, and its consequence: when properly timed, administration of growth hormone (or enhancer) causes circulating growth hormone levels to increase during sleeptime (when growth hormone normally reaches a peak in young, healthy individuals). This sleeptime growth hormone increase is responsible for the beneficial effect on lipid and glucose metabolism.

SUMMARY OF THE INVENTION

One aspect of this invention relates to a method for determining the adjustment needed, and then adjusting the sleeptime growth hormone profile of a subject in need of such treatment so that the subject's profile conforms to or approaches the normal sleeptime profile of a young, healthy member ofthe same species which comprises the steps of: comparing the growth hormone profile of the subject to the normal growth hormone profile of young, healthy subjects of the same species; determining that the subject is in need of growth hormone profile adjustment if the subject's sleeptime growth hormone levels are lower than normal; and adjusting the sleeptime growth hormone profile of the subject having an abnormal growth hormone daily rhythm to generally approach or conform the abnormal rhythm to the growth hormone profile of the young, healthy subjects.

A variation of this aspect of the invention involves (a) comparing only a set of key (typically four) growth hormone levels of the first subject measured at time points during an interval of the night from 23:00 to 04:00 to the corresponding growth hormone levels of healthy subjects at the same time points during the night, and (b) adjusting the growth hormone levels of the first subject to conform to or approach the corresponding healthy growth hormone levels. A "young" human subject is defined as a healthy, lean male or female between the ages of 20 and 35. The individuals are healthy in the sense that they are free of physiologic disorders or pathologies. In particular, they are not obese

(based on standard age/ size/weight tables); and suffer from no malignancies or autoimmune disorders or genetically transmitted diseases; altematively, healthy is a subject with a sleeptime growth hormone profile as in Figure 1 (or within 1 SEM thereof) and, preferably, with a daily prolactin profile as in Figure 2, or within 1 SEM thereof.

A second aspect of this invention relates to a method for determining the treatment to be given to a human subject suffering from a lipid or glucose disorder, which comprises the steps of:

(a) comparing the growth hormone profile of said subject, said profile having been determined over a sleeptime period, to a predetermined standard sleeptime growth hormone profile for healthy human subjects; and

(b) determining whether said human subject has an abnormal daily growth hormone profile by ascertaining whether at any of several time points during the interval from 23:00 to 04:00 the subject's growth hormone level is lower than 1 SEM below the mean growth hormone level of normal (healthy) individuals at the same time points.

Preferably, the time points compared will be actual growth hormone measurement points (i.e. the growth hormone levels of the subject being tested will be blood growth hormone levels and not extrapolations) and, most preferably, the determination will be based on four growth hormone measurement points.

A third aspect of this invention relates to a method for determining whether adjustment will be required to ameliorate an abnormal growth hormone profile or level and cause it to generally conform to or approach a standard (or healthy) growth hormone profile or level, the method comprising: (a) collecting a plurality of blood samples from a subject over a sleeptime period, the collection of said samples being made at predetermined time intervals (or at predetermined time points) within said time period; (b) assaying the growth hormone content of each of said samples; (c) plotting the growth hormone content of each of said samples against the time at which said sample was collected during said time period to generate a plurality of data points (i.e. correlating the growth hormone content with the time); (d) generating a growth hormone profile by connecting (or otherwise fitting a curve through) said data points; and (e) comparing the growth hormone profile to a predetermined normal growth hormone profile. Steps (c) and (d) together constitute an example of a method or step of expressing the growth hormone content as a function of time to generate the sleeptime growth hormone profile of the subject.

A fourth aspect of this invention relates to a method for determining adjustments that will cause an abnormal daily growth hormone profile of a patient to conform to or approach a normal individual's daily growth hormone profile, which comprises: (a) comparing the growth hormone profile of the patient to a predetermined standard growth hormone profile for healthy, young (normal) subjects; (b) determining that the growth hormone level of such patient at any time point (preferably a plurality of growth hormone measurement points, most preferably four growth hormone measurement points) during the hours of 23:00 to 04:00 is below the corresponding growth hormone level of normal healthy individuals at the same time point by at least one SEM; (c) determining the time at which to administer growth hormone or a growth hormone enhancer to said subject; and (d) selecting the amount of growth hormone to adjust a subject's aberrant growth hormone level so that the subject's growth hormone profile conforms to or approaches the growth hormone profile of normal (healthy) individuals. It is preferred that if the determination is based on less than four growth hormone measurement points being aberrant, the variation from the normal profile be at least 2 SEM.

A fifth aspect of the invention relates to methods for modifying at least one of lipid and glucose metabolism in a subject in need of treatment having abnormally low sleeptime growth hormone levels which comprises administering to the subject a substance selected from the group consisting of growth hormone and a growth hormone enhancer on a daily basis at from about one hour before bedtime to about bedtime. A sixth aspect of the invention relates to method for treating at least one of lipid and glucose metabolism disorders in a subject in need of treatment having abnormally low sleeptime growth hormone levels which comprises administering to said subject a substance selected from the group consisting of growth hormone and a growth hormone enhancer, on a daily basis at from about one hour before bedtime to about bedtime, thereby accomplishing at least one of decreasing body fat stores, decreasing hyperlipoproteinemia, decreasing hypertriglyceridemia, decreasing insulin resistance, decreasing blood glucose and decreasing hyperinsulinemia.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is further described with respect to the annexed drawings in which:

Fig. 1 is a graph of average plasma growth hormone levels (ng/ml) for young, healthy individuals v. time of day (hours). Fig. 2 is a graph of average plasma prolactin levels (ng/ml) for young, healthy male and female individuals v. time of day (hours).

DETAILED DESCRIPTION OF THE INVENTION

All patents, patent applications and literature references cited herein are incorporated by reference in their entirety as if their disclosures were physically present in the present specification. In case of conflict, however, the present disclosure, including definitions, controls.

It has recently been discovered that metabolic disorders such as the foregoing are associated with aberrant pattems in the daily levels (and fluctuations) of growth hormone and neural oscillators such as those associated with dopamine and serotonin. Healthy (normal) subjects, i.e. , lean members of a species not suffering from such metabolic abnormalities or any other pathologies have highly predictable daily growth hormone profiles, which in humans have a characteristic sharp rise to a peak in the hours following the onset of sleep (23:00 to 4:00). "Healthy" individuals have growth hormone profiles that are at within 1 SEM of the standard growth hormone profile of Fig. 1 , preferably for at least four growth hormone levels measured at different times or within 2 SEM of the standard growth hormone profile for at least two measured growth hormone levels. In the present context "lean" means not obese and not abnormally underweight. In turn, an obese human is defined as a human whose body weight is over twenty percent above the ideal body weight for a given population (R.H. Williams, Textbook of Endocrinology, 1974, pp. 904-916). An abnormally underweight human is anyone at least 10% below his/her ideal body weight. Ideal body weight (IBW) can be determined by using the Metropolitan Life Insurance Company standard age/height/weight charts.

A growth hormone profile of a subject can be obtained by collecting blood samples from the subject at timed intervals during a consecutive time period (preferably at 1 - 3 hour intervals over approximately a 12-hour period during the night-time, or a full 24 hour period, if desired), assaying each blood sample for growth hormone content, plotting the time of blood sampling against the quantity of growth hormone present in each sample to generate a data point for each sample, and connecting the data points (or otherwise fitting them into a curve) to form the growth hormone profile. In one altemative (for the vast majority of subjects) a set of only a few growth hormone levels need be obtained by collecting blood samples from the subject at spaced apart times at least twice and preferably at least four times during a specific interval of a 24-hour period. The specific interval of the present invention is during the early hours of deep sleep (23:00 - 04:00). Spaced apart samples may be collected for example at 24:00, 01:00, 02:00, and 03:00; or at 23:00, 24:00, 01:00 and 02:00.

This altemative method is preferred in clinical practice to obtaining growth hormone profiles for longer time periods for several reasons. First, such a procedure is significantly less costly than those involving additional blood draws. Second, the reduced number of blood samples drawn is preferred by patients as it is significantly less dismptive to their daily schedules. The growth hormone levels taken from 23: 00 to 04: 00 are used as indicators of the subject's growth hormone profile, and as substitutes thereof.

The present invention encompasses methods which include (a) both the determination that growth hormone levels in a subject are abnormal and the administration of growth hormone at a predetermined time, as well as (b) methods which include only the administration of growth hormone at a predetermined time, it having been determined by someone not practising the administration of growth hormone that the growth hormone level of a subject is abnormal. Individuals who suffer from one or more metabolic disorders have abnormally low (often very low) sleeptime growth hormone profiles and levels. These growth hormone profiles and levels not only differ substantially from the norm but they can also differ from one another. As employed herein the term "sleeptime" means the period of time which in normal humans growth hormone level rises to a peak (between 23:00 and 04:00).

As employed herein, "growth hormone" means human growth hormone.

As employed herein "growth hormone enhancers" are those compounds that directly or indirectly raise the blood level of growth hormone when administered to a subject, by either raising endogenous growth hormone production or retarding elimination of growth hormone from the bloodstream, and include, but are not limited to melatonin, arginine, tryptophan as well as dopamine agonists and somatostatin inhibitors.

The normal average peak value of growth hormone between the hours of 23:00 and 02:00 is about 8 + 2 nanograms/ml of blood plasma (see Fig 1).

DEVELOPMENT OF THE "NORMAL" GROWTH HORMONE PROFILE

A statistically significant number of healthy and young (20-35 years of age) humans are selected as follows:

All subjects are healthy and on normal diurnal work/ rest schedule (no night guards or other night-shift workers). All subjects must normally sleep between about 23:00 and about 07:00. The individuals are healthy in the sense that they are free of physiologic disorders or pathologies. In particular, they are not obese (based on standard age/ size/weight tables); and suffer from no malignancies or autoimmune disorders or genetically transmitted diseases. A statistically significant number shall mean at least 3, the smallest sampling number for which statistical formulas generally have any meaning. However, a sampling number of at least 6 is generally preferred (at least 10 is more preferred) because this amount of sampling generally reduces the standard error (SE) of growth hormone determinations. Blood is collected from each subject at 1-3 hour intervals over the night¬ time hours, or, if desired a full 24-hour period and diurnal plasma levels of growth hormone are measured for each subject e.g. , blood is collected over a 24-hour period at suitable time intervals (e.g. , every 1 to 3 hours). Suitable sampling techniques and assay procedures are well-known to those skilled in the field.

During sampling, all subjects must consume the same diet and maintain the same sleeptime schedule. Growth hormone data are plotted against time of day and a normal growth hormone curve is developed including the standard error of the mean

(SEM). Mathematical expressions can also be developed to describe the curves and the area under the curves.

The result of a normal 24 hour profile is shown in Figure 1. The SEM for growth hormone levels in humans during the key sleeptime hours is about 2 ng/ml. Altematively, the curve of Fig. 1 , particularly its sleeptime region, can be used as the standard growth hormone profile (as well as for the standard growth hormone levels at times corresponding to key growth hormone measurements); or only a set of (preferably at least 4) growth hormone levels can be measured in healthy subjects at a specific sleeptime interval, e.g., during the period from 23:00 to 04:00.

DETERMINATION OF DIURNAL GROWTH HORMONE

PROFILES OF SUBJECTS SUFFERING FROM LIPID OR GLUCOSE METABO¬ LISM DISORDERS

The procedures described above can be used to develop a 24 hour growth hormone profile (or a set of specific, sleeptime levels of growth hormone) for individuals under clinical evaluation for therapy according to the present invention. Individuals that are expected to have an abnormal daily growth hormone rhythm include those having been diagnosed as afflicted with at least one of the following conditions: obesity (i.e. , more than 20% overweight, based on age, frame size and sex characteristics using tables such as the Metropolitan Life Insurance Company tables for standard weight for height and age), insulin-resistance, hyperglycemia, hyperinsulinemia, hyperlipoproteinemia, hypertriglyceridemia, or Type π diabetes. However, the present evaluation is not limited to such subjects.

Once a diurnal growth hormone level profile has been developed for an individual, the profile is compared to the "normal" profile (e.g. , the one generated as described in the previous section or to Fig. 1). A determination can then be made based on the following general criteria: from about 23:00 h till about 04:00 h, i.e., during the sleeptime peak of the normal daily growth hormone profile, the individual's growth hormone profile must first have a peak at about the same time or within two to six hours after sleep initiation as the "normal" growth hormone peak for subjects in the same category (usually about 01:00) and must also be within one SEM of the normal healthy growth hormone profile (preferably for four growth hormone readings or alternatively within two SEM for at least two growth hormone readings).

To determine if a subject has an aberrant growth hormone profile the bedtime on the subject's growth hormone profile should ideally be coincident with the bedtime on the profile of normal subjects. If this is not the case, the profile of the subject and the profile of normal individuals can be superimposed and one or the other can be shifted so that the sleep initiation time of the subject to be tested coincides with the sleep initiation time of normal healthy subjects.

DETERMINATIONOFTREATMENTFORANAFFECTED SUBJECT

The information (growth hormone profile or set of sleeptime growth hormone levels) generated as described above can be used to (a) identify the patients that are in need of an adjustment in their growth hormone profile and (b) to determine the type and extent of adjustment required. In general, those individuals that are obese, hyperinsulinemic, hyperlipoproteinemic, hypertriglyceridemic, hyperglycemic and/or diabetic display abnormal growth hormone profiles (or sleeptime growth hormone levels) as compared to healthy individuals. Simply stated, by comparing a subject's growth hormone profile (or sleeptime growth hormone levels) with the standard growth hormone profile, or corresponding healthy (normal) set of growth hormone levels, it is possible to identify individuals afflicted with the abnormal conditions discussed above. By adjusting the abnormal growth hormone profile of such individuals by administration of growth hormone or a growth hormone enhancer at the appropriate time of day and in the appropriate dosage (amount) it is possible to adjust such individuals' growth hormone profile to conform (or at least approach) a normal profile. The amount and timing of administration of such dosages can be determined based upon information contained in the growth hormone profiles (or sleeptime growth hormone levels) discussed above, and based on the time it takes for the administered growth hormone or growth hormone enhancer to raise the growth hormone levels in the subject's bloodstream.

An adjusted profile approaches a normal or healthy profile if all or a portion of the abnormal profile moves in the correct direction by at least 2 ng/ml. For example, if a human subject's abnormal growth hormone level is 4 ng/ml between 24:00 and 01:00 and (after adjustment) it is increased to 6 ng/ml during the same time period, the adjusted profile approaches the healthy profile. It is thus important to increase the area under the sleeptime growth hormone curve (by at least about 10% and typically at least about 20%). It is also desirable not to exceed the normal sleeptime growth hormone levels by more than 2 and preferably not more than 1 SEM (4 ng/ml and 2 ng/ml of plasma, respectively).

The treatment determination has two aspects: (a) timing of (each) dose of administration; and (b) amount of (each) dose to be administered. Whether a full 24-hour or full night-time growth hormone profile is generat¬ ed for a subject to be treated, or only key sleeptime growth hormone levels are measured, the following more specific guidelines will generally be followed to initially determine growth hormone or growth hormone enhancer administration timing, for a period of treat¬ ment of approximately 10 days to 26 weeks. Growth hormone is administered once a day, about one hour before bedtime. Generally, the daily dosage range by subcutaneous injection is from about 0.003 to about 0.3 mg/kg; the preferred subcutaneous daily dosage is about 0.03 mg/kg. By the intravenous route, the daily dosage range is from about 0.0003 to about 0.003 mg/kg; the preferred daily intravenous dosage is about 0.003 mg/kg. Growth hormone enhancers (generally daily dosage range depends on bioavailability, method of administration and ability of the active ingredient to raise blood growth hormone levels, as well as the patient's ability to respond. Examples of typical dosage starting points for therapy are: for melatonin, 0.04 mg/kg/day; for arginine, 15 mg/kg/day; and for tryptophan, 7 mg/kg/day, all administered orally at bedtime or up to an hour before bedtime. The adjustment to dosage and/or time of administration can be made after monitoring the sleeptime growth hormone levels of the patient.

Growth hormone administered parenterally is preferred. Recombinant human growth hormone is available commercially and is normally administered subcutaneously or intravenously, although any method of administration that does not result in degradation of the hormone (such as takes place by passage of unprotected polypeptides through the digestive tract) is in principle possible (although the amount may have to be adjusted). If a growth hormone enhancer is administered, it may be selected from a variety of substances that are known to cause the release of growth hormone, such as somatostatin inhibitors (not preferred), D2 dopamine agonists (such as bromocriptine, 2-bιomo-alpha-ergocriptine; 6-methyl-8 beta-ca.tbobenzyloxy-ammoethyl-10-a-pha-ergoline; 8-acylaminoergolines, are 6-methyl-8-alpha-(N-acyl)amino-9-ergoline and 6-methyl-8 alpha-(N-phenylacetyl)am o-9-ergoUne;ergocom-ne;9,10-d-hydroergocomine;D-2-halo- 6-alkyl-8-substituted ergolines, e.g., D-2-bromo-6-methyl-8-cyanomethylergoline; and lisuride, and the non-toxic salts of the prolactin-inhibiting ergot-related compounds formed from pharmaceutically acceptable acids), and other growth hormone-enhancing substances such as melatonin, tryptophan, and arginine. Under the present state of the art, the last three are preferred because they can be administered orally, and are normally unaccompa- nied by toxic side effects. In the practice of this invention, the growth hormone enhancer can administered daily to a subject preferably orally (in the form of tablets, caplets, capsules, or the like) or by subcutaneous, intravenous or intramuscular injection. Dermal delivery systems e.g., skin patches, as well as suppositories and other well-known systems for administration of pharmaceutical agents such as by inhalation of an atomized solution can also be employed.

The foregoing are applicable for setting initial therapy regimens. Growth hormone and growth hormone enhancers such as tryptophan, arginine, and melatonin are normally administered within about 1 hour prior to retiring for the patient's normal sleep period. If another growth hormone enhancer is administered, it should be administered at a time predetermined to increase growth hormone levels during the 23:00 to 04:00 interval. For example, D2 dopamine agonists are administered in the morning, generally between the 05:00 and 12:00. (It is interesting that administration at the appropriate time of these substances increases sleeptime growth hormone levels which may occur 20 hours later. This shows that the effect on growth hormone is not an acute effect but involves entraining or resetting hormonal circadian rhythms). The efficacy of a particular regimen on a particular patient and the adjustments (in dosage and timing) required, if any, can be determined by comparing the patient's re-evaluation growth hormone profile or reevaluation sleeptime growth hormone levels with the standard profile (or the "healthy" sleeptime profile levels). Adjustments to the amount(s) of drug(s) administered and possibly to the time of administration may be made as described above based on reevaluations.

The present timed daily treatment is typically continued over a period of time ranging from about 10 days to usually about 180 days, resulting in modification and resetting of the lipid and glucose metabolism of the patient to that of a lean (i.e. , normal) healthy person, at which time treatment may be discontinued. For some patients (e.g. patients in particularly poor physical condition, or those of an advanced age) it may not be possible to reset their growth hormone rhythm within the above time periods and such patients may require a longer, or even continuous, treatment with growth hormone.

Body fat deposits, inclusive of adipose, arterial wall and plasma fat, of an obese person will be reduced, leveled out and generally maintained (after the treatments of the present invention are discontinued) at that of a normal (lean) person, over an extended period of time. A subject that exhibits the effects of insulin resistance, hypertriglyceridemia or hyperinsulinemia and/or hyperglycemia, or both insulin resistance and hyperinsulinemia and/or hyperglycemia, treated with the growth hormone at the appropriate times of day discussed above, will become more sensitive to insulin (i.e., will have a lower insulin resistance), and the effects of hyperinsulinemia and/or hyperglycemia and related abnormal metabolic values will be reduced on a long term basis. Treatment generally lasts between about 10 and about 180 days on average in humans, but longer treatment is possible. The administration of the growth hormone or growth hormone enhancer in this manner will thus reset the phase relations of neural oscillations and then- various circadian expressions to alter metabolism on a long term basis (e.g., several months or years), if not permanently. In other words, the result of the timed daily administration of growth hormone or a growth hormone enhancer will be a long term reversal of the major pathologies generally associated with the development of Type π diabetes. Using the methods of the present invention, the levels of body fat stores, plasma insulin concentrations (including in patients oral hypoglycemic medications), insulin resistance, hyperglycemia, and blood pressure or all of these pathologies can be reduced on a long term basis by such treatment, or treatments, from the high levels often found in obese, hyperinsulinemic, hyperlipidemic and/or hyperglycemic persons to approach or conform to the much lower and much more desirable levels found in normal persons with normal insulin levels.

The following is a working example of the present invention intended to illustrate it without limiting its scope.

EXAMPLE 1: Treatment of Obesity and Lipid or Glucose Metabolism Disorders with Growth Hormone The growth hormone to be used for treatment is obtained from commercial sources, such as Genentech, Novo-Nordisk, or BioTechnology General.

The growth hormone is administered at a time from about one hour before bedtime up until bedtime to patients who are obese or who are suffering from lipid or glucose metabolism disorders and who have been determined to have abnormal key growth hormone levels.

The growth hormone is administered subcutaneously. In a preferred embodiment, a total dose of 30 μg per day is administered subcutaneously. Growth hormone is administered daily for a period of at least 10 days up to about 26 weeks, Timed daily administration of growth hormone will result in one or more of the following effects on lipid and glucose metabolic indices in the patients being treated: decreased body fat stores, decreased hyperlipoproteinemia, decreased hypertrigly¬ ceridemia, decreased insulin resistance, decreased blood glucose and decreased hyperinsulinemia.

Claims

WHAT IS CLAIMED IS: l. A method for determining whether a vertebrate test subject having a daily growth hormone rhythm is in need of administration of growth hormone or a growth hormone enhancer that will cause an abnormal daily growth hormone rhythm to approach or conform to the daily growth hormone rhythm for healthy subjects, which comprises: (a) measuring the blood growth hormone level of the test subject at least four times during sleeptime to obtain a sleeptime growth hormone level; (b) comparing said sleeptime growth hormone level to a corre- sponding predetermined standard sleeptime growth hormone level for healthy subjects of the same species at the same sleeptime time points; and (c) determining that. the test subject should be administered growth hormone or a growth hormone enhancer to increase sleeptime growth hormone levels of the test subject in the event that said sleeptime growth hormone level obtained from four measurements is lower than the corresponding standard sleeptime growth hormone level of healthy subjects by more than 1 standard error of the mean.

2. A method for identifying in a group of human subjects being tested a subject in need of administration of growth hormone or a growth hormone enhancer that will cause an abnormal daily growth hormone rhythm to approach or conform to a healthy subject's daily growth hormone rhythm, which comprises the steps of: (a) measuring the blood growth hormone levels of said subjects at least four times during sleeptime to obtain a sleeptime growth hormone level; (b) comparing the growth hormone levels to a corresponding standard growth hormone level for healthy subjects at the same time points; and (c) determining that a subject should be administered growth hormone or a growth hormone enhancer to increase sleeptime growth hormone levels of the subject in the event that said sleeptime growth hormone level obtained from four measurements is lower than the corresponding standard sleeptime growth hormone level of healthy subjects by more than 1 standard error of the mean.

3. A method for determining whether a human subject is in need of administration of growth hormone or a growth hormone enhancer that will cause an abnormal daily growth hormone rhythm to approach or conform to a healthy subject's daily growth hormone rhythm, which comprises the steps of: (a) collecting blood samples from the subject at least four times during sleeptime; (b) measuring the growth hormone content of each of said samples; (c) plotting the growth hormone content of each of said samples against the time at which said sample was collected to generate a sleeptime growth hormone level data point; (d) comparing said sleeptime growth hormone level data points to a corresponding predetermined standard growth hormone profile for healthy subjects at the same day time points; and (e) determining that the subject should be administered growth hormone or a growth hormone enhancer to increase sleeptime growth hormone levels of the subject in the event that each of at least four of said growth hormone levels measured during said sleeptime is below the growth hormone level of healthy subjects at the same time point by more than 1 standard error of the mean.

4. The method of claim 1 wherein said first subject suffers from Type π diabetes.

5. The method of claim 1 wherein said first subject suffers from obesity.

6. The method of claim 1 wherein said first subject suffers from hypertriglyceridemia.

7. The method of claim 2 wherein said subjects suffer from Type π diabetes.

8. The method of claim 2 wherein said subjects suffer from obesity.

9. The method of claim 2 wherein said subjects suffer from hypertriglyceridemia.

10. The method of claim 3 wherein said subject being tested suffers from Type π diabetes.

11. The method of claim 3 wherein said subject tested suffers from obesity.

12. The method of claim 3 wherein said subject being tested suffers from hypertriglyceridemia.

13. The method of claim 1 further comprising the step: (d) adjusting the subject's sleeptime growth hormone level to approach or conform to the standard sleeptime growth hormone level.

14. The method of claim 2 further comprising the step: (d) adjusting the subject's sleeptime growth hormone level to approach or conform to the standard sleeptime growth hormone level.

15. A method for treating at least one of lipid and glucose metabolism disorders in a subject in need of treatment having abnormally low sleeptime growth hormone levels comprising: administering to said subject a substance selected from the group consisting of growth hormone and a growth hormone enhancer on a daily basis at a predetermined time to cause the subject's sleeptime growth hormone levels to conform to or approach the corresponding sleeptime levels of a healthy subject of the same species at the same time points, thereby accomplishing at least one of the following: decreasing body fat stores, decreasing hyperlipoproteinemia, decreasing hypertriglyceridemia, decreasing insulin resistance, decreasing blood glucose and decreasing hyperinsulinemia.

16. A method for decreasing in a subject in need of treatment having abnormally low sleeptime growth hormone levels, at least one of the following metabolic indices: body fat stores, hyperlipoproteinemia, hypertriglyceridemia, insulin resistance, blood glucose and hyperinsulinemia; said subject having a set of sleeptime growth hormone levels lower by at least one SEM than the corresponding growth hormone levels of a young, healthy subject at the same time points, the method comprising: administering to said subject a substance selected from the group consisting of growth hormone and a growth hormone enhancer on a daily basis at a predetermined time to cause the subject's sleeptime growth hormone levels to conform to or approach the corresponding sleeptime levels of a healthy subject of the same species at the same time points.

17. A method for modifying at least one of lipid and glucose metabolism in a subject in need of treatment having abnormally low sleeptime growth hormone levels comprising: administering to said subject a substance selected from the group consisting of growth hormone and a growth hormone enhancer, on a daily basis at from about one hour before bedtime to about bedtime.

18. A method for treating at least one of lipid and glucose metabolism disorders in a subject in need of treatment having abnormally low sleeptime growth hormone levels comprising: administering to said subject a substance selected from the group consisting of growth hormone and a growth hormone enhancer, on a daily basis at from about one hour before bedtime to about bedtime, thereby accomplishing at least one of the following: decreasing body fat stores, decreasing hyperlipoproteinemia, decreasing hypertriglyceridemia, decreasing insulin resistance, decreasing blood glucose and decreasing hyperinsulinemia.

19. The method of claim 17, wherein said administering causes said subject's sleeptime growth hormone levels to conform to or approach the corresponding sleeptime levels of a healthy subject of the same species at the same time points.

20. The method of claim 18, wherein said administering causes said subject's sleeptime growth hormone levels to conform to or approach the corresponding sleeptime levels of a healthy subject of the same species at the same time points.