Carbohydrate metabolism in male infertility and female fertility-control patients

Metabolic and Genetic Markers Improve Prediction of Incident Type 2 Diabetes: A Nested Case-Control Study in Chinese

CONTEXT

It is essential to improve the current predictive ability for type 2 diabetes (T2D) risk.

OBJECTIVE

We aimed to identify novel metabolic markers for future T2D in Chinese individuals of Han ethnicity and to determine whether the combined effect of metabolic and genetic markers improves the accuracy of prediction models containing clinical factors.

METHODS

A nested case-control study containing 220 incident T2D patients and 220 age- and sex- matched controls from normoglycemic Chinese individuals of Han ethnicity was conducted within the Wuxi Non-Communicable Disease cohort with a 12-year follow-up. Metabolic profiling detection was performed by high-performance liquid chromatography‒mass spectrometry (HPLC-MS) by an untargeted strategy and 20 single nucleotide polymorphisms (SNPs) associated with T2D were genotyped using the Iplex Sequenom MassARRAY platform. Machine learning methods were used to identify metabolites associated with future T2D risk.

RESULTS

We found that abnormal levels of 5 metabolites were associated with increased risk of future T2D: riboflavin, cnidioside A, 2-methoxy-5-(1H-1, 2, 4-triazol-5-yl)- 4-(trifluoromethyl) pyridine, 7-methylxanthine, and mestranol. The genetic risk score (GRS) based on 20 SNPs was significantly associated with T2D risk (OR = 1.35; 95% CI, 1.08-1.70 per SD). The area under the receiver operating characteristic curve (AUC) was greater for the model containing metabolites, GRS, and clinical traits than for the model containing clinical traits only (0.960 vs 0.798, P = 7.91 × 10-16).

CONCLUSION

In individuals with normal fasting glucose levels, abnormal levels of 5 metabolites were associated with future T2D. The combination of newly discovered metabolic markers and genetic markers could improve the prediction of incident T2D.

Pharmacological agents that directly modulate insulin secretion

Blood glucose levels are sensed and controlled by the release of hormones from the islets of Langerhans in the pancreas. The beta-cell, the insulin-secreting cell in the islet, can detect subtle increases in circulating glucose levels and a cascade of molecular events spanning the initial depolarization of the beta-cell membrane culminates in exocytosis and optimal insulin secretion. Here we review these processes in the context of pharmacological agents that have been shown to directly interact with any stage of insulin secretion. Drugs that modulate insulin secretion do so by opening the K(ATP) channels, by interacting with cell-surface receptors, by altering second-messenger responses, by disrupting the beta-cell cytoskeletal framework, by influencing the molecular reactions at the stages of transcription and translation of insulin, and/or by perturbing exocytosis of the insulin secretory vesicles. Drugs acting primarily at the K(ATP) channels are the sulfonylureas, the benzoic acid derivatives, the imidazolines, and the quinolines, which are channel openers, and finally diazoxide, which closes these channels. Methylxanthines also work at the cell membrane level by antagonizing the purinergic receptors and thus increase insulin secretion. Other drugs have effects at multiple levels, such as the calcineurin inhibitors and somatostatin. Some drugs used extensively in research, e.g., colchicine, which is used to study vesicular transport, have no effect at the pharmacological doses used in clinical practice. We also briefly discuss those drugs that have been shown to disrupt beta-cell function in a clinical setting but for which there is scant information on their mechanism of action.

Comparative clinical evaluation of the effect on carbohydrate and lipid metabolism of two norethisterone-containing hormonal contraceptives: Mesigyna and TriNovum

The effect on carbohydrate and lipid metabolism of two hormonal contraceptive preparations containing norethisterone (commercially known as Mesigyna and TriNovum) was studied in a total of 60 women, before and after 6 months of treatment. Carbohydrate metabolism was evaluated by means of a euglycemic glucose clamp test; lipid metabolism was monitored by measuring total cholesterol, HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol, and triglycerides. The two groups were properly matched with the exception of pretreatment levels of cholesterol and LDL-cholesterol. At the end of treatment, no difference was found within or between groups in fasting glucose and insulin levels and in glucose rate of disappearance. A significant increase in total cholesterol, HDL-cholesterol, and VLDL-cholesterol was found in both groups at the end of the treatment period; in addition, TriNovum caused a significant increase also in triglycerides. In conclusion, the safety of both preparations with regard to carbohydrate metabolism was confirmed using the most accurate method available; furthermore, changes in lipid metabolism were such as to have little clinical significance.

Effects of selected hormones on the motility of spermatozoa in the mouse vas deferens

Acting in vivo, adrenalin and noradrenalin cause a statistically significant and permanent decrease in the motility of mouse spermatozoa remaining in the vas deferens. Intratesticular injection of vasopressin, oxytocin, insulin, and glucagon results in a decrease in spermatozoa motility in vas deferens, removal the spermatozoa to PBS in vitro, and an increase in percentage of motile spermatozoa on incubation medium. Thyroxine, calcytonin, and TRH did not affect motility of mouse spermatozoa in vivo.

Carbohydrate metabolism studies after one year of using an oral contraceptive containing gestodene and ethinyl estradiol

The objective of the study is to evaluate the effects of a gestodene-containing oral contraceptive on carbohydrate metabolism. The design of the study is prospective. The setting is at University of South Florida Outpatient Unit. The patients consisted of twenty-three normal women desiring contraception. Serum glucose and insulin levels were measured during a three-hour glucose tolerance test at control time and after one year of drug use.

RESULTS

All of the one-year glucose values were significantly elevated as well as the fasting and three-hour insulin values. These changes were mostly confined to women over 26 years of age and not in the younger 18 to 23 year olds. An oral contraceptive containing 75 micrograms of gestodene and 30 micrograms of ethinylestradiol can significantly alter carbohydrate metabolism in older women.

The metabolic impact of oral contraceptives

The hormonal components of oral contraceptives exert major effects on plasma lipoprotein metabolism. Estrogens may increase production of plasma triglycerides, leading to increased levels of very low-density lipoproteins, but they may also reduce levels of cholesterol-enriched and potentially atherogenic intermediate- and low-density lipoproteins. Furthermore, estrogens increase levels of high-density lipoproteins (HDLs), particularly the HDL2 subspecies, an effect linked to reduced mortality rates from cardiovascular disease in postmenopausal women receiving hormone replacement therapy. All combination oral contraceptives in use in the United States tend to raise levels of plasma triglycerides, low-density lipoprotein, and HDL3 to varying degrees. In contrast, changes in HDL and HDL2 reflect the combined effects of estrogen dose and relative androgenicity of the progestin component. Although in general, the lipoprotein changes are greater in magnitude with higher dose oral contraceptive preparations, they can be significant in lower dose preparations as well. Oral contraceptives also affect carbohydrate metabolism, primarily through the activity of progestin. Studies have demonstrated insulin resistance, rises in plasma insulin, and relative glucose intolerance by means of curve analysis of glucose tolerance tests. These effects are far less pronounced with lower dose preparations and with formulations using the newer progestins.

Oral contraceptive use and the risk of type 2 (non-insulin-dependent) diabetes mellitus in a large prospective study of women

We examined the association between oral contraceptive use and incidence of Type 2 (non-insulin-dependent) diabetes mellitus among 115117 female nurses free of diabetes, cardiovascular disease and cancer in 1976 and followed-up for 12 years. During 1237440 person years of follow-up, 2276 women who provided information on oral contraceptive use were clinically diagnosed with Type 2 diabetes. Women who used oral contraceptives in the past had only a slight and marginally increased relative risk of 1.10 (95% confidence interval 1.01, 1.21) compared to those women who had never used oral contraceptives after controlling for known risk factors of disease. We found no evidence of increased risk with longer duration of use or with shorter interval since last use. Current users did not have an increased risk of Type 2 diabetes (relative risk = 0.86, 95% confidence interval 0.46, 1.61) when compared to women who had never used the drug. There was no effect modification by obesity, family history of diabetes, or physical activity. These data suggest that past or current oral contraceptive use does not substantially influence subsequent risk of Type 2 diabetes.

Carbohydrate metabolism after three months of using a gestodene-containing monophasic oral contraceptive

Carbohydrate metabolism was prospectively evaluated in twenty-one normal women prior to and during their use for three months of a monophasic oral contraceptive containing the progestin gestodene plus ethinyl estradiol. The women had a three-hour oral glucose tolerance test using a 75 gram glucose load, measuring serum glucose and insulin levels. The results demonstrate no significant changes in either of the carbohydrate metabolic indices between the two tests. These data support the safety of this new progestin-containing contraceptive.

A comparative study of oral glucose tolerance tests in Nigerian women on three types of steroidal contraceptives

Oral glucose tolerance tests (OGTT) were performed on 146 Nigerian women volunteers using one of three types of steroidal contraceptives: high-dose combined pills; low-dose combined pills and injectable progesterone. Twenty-six appropriately matched nonusers served as controls. The OGTT curves were analysed using the H-index (HI). Women on injectable progesterone and high-dose combined pills, respectively, had significantly higher (P less than 0.05) mean HI than the controls. The low-dose combined pills had the least effect on carbohydrate metabolism.

An open prospective study on the effects on carbohydrate metabolism of an oral monophasic contraceptive containing gestodene (WL-70)

The effects of a monophasic oral contraceptive (gestodene 75mcg + ethinylestradiol 30 mcg) on plasma glucose (PG) and insulin (IRI) responses to an oral glucose load (OGTT) and on glycosylated haemoglobin Alc (HbAlc), fructosamine (Fr), total cortisol (FT) and transcortin (CBG) were studied in 30 healthy women. Blood samples were taken before treatment and after 6 and 12 cycles. After 6 and 12 months, OGTT-PG and IRI levels showed substantially unchanged values; for HbAlc and Fr the same behaviour was seen with the exception of the latter between 6 and 12 months; FT and CBG showed significant rises. All recorded values were in the normal range. The basal and dynamic PG and IRI behaviour failed to show any significant variations between pre-treatment values and those after 6 and 12 months of OC administration. Other data showed a substantial neutrality for this oral contraceptive containing gestodene.

Carbohydrate metabolic studies in women using a levonorgestrel/ethinyl estradiol containing triphasic oral contraceptive for eighteen months

Carbohydrate metabolism was evaluated in 17 women before and after 18 months of triphasic oral contraceptive use. The triphasic oral contraceptive contained levonorgestrel and ethinyl estradiol. An oral glucose tolerance test was utilized and both plasma glucose and insulin levels were measured. There were no significant changes in the glucose levels. The fasting insulin level was raised at the 18-month test, whereas the other insulin values were similar. These results demonstrate that the new triphasic oral contraceptive preparations produce minimal carbohydrate metabolic changes.

Semen characteristics and diabetes mellitus: significance of insulin in male infertility

A study was made of semen quality and serum hormonal profiles (FSH, LH, prolactin, testosterone) of patients with type I diabetes mellitus. Semen parameters and levels of prolactin and testosterone were significantly altered in the diabetic state. The concentration of insulin in serum and seminal plasma and the serum levels of FSH, LH, and testosterone were measured in 80 men classified in the following groups: fertile subjects, infertile normoglycemic subjects, subjects with carbohydrate intolerance, and excretory and secretory azoospermic subjects. In all groups, seminal insulin concentrations were higher than those obtained in serum. The hormone appears to freely cross the blood-testis barrier, there to be concentrated in the semen. The levels of insulin in serum and seminal plasma did not correlate with semen parameters and are not suitable markers of seminal quality. For unknown reasons, the concentrations of insulin in seminal plasma were lower in the subjects suffering from carbohydrate intolerance.

Two-year carbohydrate metabolism studies in women using a norethindrone or levonorgestrel triphasic oral contraceptive

Carbohydrate metabolism was prospectively studied in 28 women using triphasic oral contraceptives (TOC) for two years. They were tested using a 100-gram oral glucose tolerance test with measurements of plasma glucose and insulin levels during the three-hour test. The women were randomly assigned to either a norethindrone-containing TOC or a levonorgestrel-containing TOC. Both types of drugs contained the estrogen ethinyl estradiol. No significant changes were noted in the norethindrone TOC group. The levonorgestrel TOC two-year test had a significant elevation of the 0.5- and 2-hour plasma glucose values and the fasting insulin value. These data show that the two triphasic oral contraceptive preparations affect carbohydrate metabolism differently.

The effects of two triphasic oral contraceptives on carbohydrate metabolism in women during 1 year of use

Sixty-one women were randomly assigned to use one of two different triphasic oral contraceptives (OCs), for one year's time (Ortho Novum 777, Ortho Pharmaceutical Corp., Raritan, NJ, and Triphasil, Wyeth Laboratories, Philadelphia, PA), containing the progestins norethindrone and levonorgestrel, respectively. The carbohydrate metabolism was evaluated using the oral glucose tolerance test before OC use and at the end of the 12th month. Both plasma glucose and insulin levels were measured. The fasting glucose value in the norethindrone-containing OC group (777) was significantly lower at the 1-year testing. All other values were unchanged. These data demonstrate that the triphasic oral contraceptive preparations currently in use have minimal effects on carbohydrate metabolism.

Prospective study of carbohydrate metabolism in women using a triphasic oral contraceptive containing norethindrone and ethinyl estradiol for 3 months

Thirty-five women with normal carbohydrate metabolism were administered a 3-hour oral glucose tolerance test before and after 3 months' use of a triphasic oral contraceptive that contained ethinyl estradiol and norethindrone. The results show no significant change in either the plasma glucose or the insulin values. This is the first published study with regard to this type of triphasic oral contraceptive, and the study supports claims of the preparation's improved safety.

Plasma glucose and insulin levels in women using a levonorgestrel-containing triphasic oral contraceptive for three months

Plasma glucose and insulin levels were measured for three hours after an oral glucose challenge in twenty-nine women before and after using a triphasic oral contraceptive containing ethinyl estradiol and levonorgestrel for three months. There were significant elevations in the glucose levels during the three-month tolerance test, while the insulin levels were unchanged. These data suggest that this OC can alter carbohydrate metabolism and that long-term studies are needed to assess the extent of this metabolic change.

Effects of natural oestrogen/progestogen substitution therapy on carbohydrate and lipid metabolism in post-menopausal women

Oral glucose tolerance tests were performed in 30 post-menopausal women before and after 1 mth and 6 mth of cyclic 17 beta-oestradiol/norethisterone acetate substitution therapy. Before undergoing treatment the patients were divided into three groups comprising subjects with normal glucose tolerance, subjects with impaired glucose tolerance and diabetic subjects receiving oral diabetic treatment respectively. Carbohydrate metabolism was evaluated during a 2-h oral glucose tolerance test following a 100 g glucose load. Both blood glucose and plasma insulin values were measured. The fasting serum cholesterol and triglyceride levels were also determined. Hormone substitution therapy had no effect on fasting blood glucose values in any of the three groups. At the end of the 6 mth substitution therapy, however, it was found that the blood glucose values in the subjects with impaired glucose tolerance were significantly lowered by the end of the 2-h test period. The glucose areas under the curve during oral glucose tolerance tests following the hormone treatment were also reduced in this same group. In the case of insulin, the areas under the curve remained unchanged in all three groups. Fasting serum cholesterol levels tended to fall, while the triglyceride levels remained unaltered, during the hormone treatment periods. However, a slight increase in triglyceride levels was observed in the subjects with impaired glucose tolerance.

Glucose metabolism in human spermatozoa: lack of insulin effects and dissociation from alloxan handling

The role of glucose metabolism in sperm cell motility was examined in purified human spermatozoa from the perspective of elucidating its possible significance in spontaneous and experimental diabetes. After a 4-h incubation in the absence of D-glucose, the mean progressive velocity of human spermatozoa was 40% lower than that of control cells kept in the presence of D-glucose. The decline was rapidly overcome by the addition of D-glucose or D-fructose, the amplitude of this stimulatory effect being independent of the ambient hexose concentration. Between 1.4 and 16.7 mM glucose, spermatozoal glucose oxidation also proceeded independently of the extracellular glucose levels, whereas both insulin (100nM) and glucagon (100nM) failed to significantly affect the rate of glucose metabolism or cellular motility. It is speculated from these results that an alteration in seminal hexose concentrations or pancreatic hormone levels may be an unlikely cause for the reduced sperm motility that is characteristically observed in diabetic patients. Human spermatozoa rapidly incorporated D-glucose and 3-O-methyl-D-glucose but excluded the glucose-analogue alloxan, which may explain their resistance against the toxic effects of this diabetogenic drug, in spite of their intrinsic sensitivity to organic peroxides such as tert-butyl hydroperoxide.

Testicular function and glycemic control in diabetic men. A controlled study

We have investigated testicular function in 28 insulin-dependent diabetic men under the age of 50 years and 119 age-matched controls. Diabetics had reduced testicular volume, semen volume, total and total motile sperm output while plasma LH and FSH levels were elevated. Reduction in semen volume and impotence were more common in long-standing complicated diabetes. Glycosylated hemoglobin (GHb) levels were positively correlated with plasma LH levels (r = 0.46, p less than 0.02) but there was no direct correlation of glycemic control and spermatogenesis. The differences in testicular function were due to decreased spermatogenesis and could not be explained by other forms of testicular pathology or the presence of diabetic neurovascular complications. We conclude that the function of the hypothalamic pituitary testicular axis is impaired in diabetic men, that this impairment is at least partly related to the degree of preceding glycemic control and that multiple levels of the axis may be dysfunctional.

Metabolic effects of the triphasic oral contraceptive Trigynon

Effects of Trigynon, a triphase low-dose oral contraceptive, containing ethinylestradiol and l-norgestrel in various proportions, on testosterone binding globulin, transcortin, thyroxine, free testosterone, free cortisol and free thyroxine as well as on plasma lipids and glucose tolerance were studied in 12 normal women treated for 3-6 months. Trigynon appears to have dominant estrogenic effects as evidenced from the increase in transport proteins and the decrease in free testosterone concentration. Plasma lipids were not significantly influenced; glucose tolerance was slightly, but not significantly decreased.

The effects of two years of mestranol treatment on carbohydrate metabolism

Twenty-nine menstrual age women who had a hysterectomy and oophorectomy were treated cyclically with 80 micrograms of mestranol per day for 2 yr. Their carbohydrate metabolism was evaluated prospectively by doing a 3 hr oral glucose tolerance test after a 100 g glucose load and measuring both blood glucose and plasma insulin levels. The tests were performed before drug treatment and after 2 yr of drug use. Those women that had a "normal" predrug test had some carbohydrate metabolism changes at the 2 yr test with significant elevations of the fasting, 1 and 2 hr blood glucose values, and also significant elevations of the 2 and 3 hr plasma insulin values. Those women with a "borderline abnormal" predrug test had no significant change in either parameter of carbohydrate metabolism however a trend toward similar changes was noted.

Carbohydrate metabolism during treatment with estrogen, progestogen, and low-dose oral contraceptives

The combination oral contraceptives have generally been shown to have an adverse effect on carbohydrate metabolism with resultant elevations of both blood glucose and insulin in users. Studies of the individual steroid components suggest that the estrogen is not at fault. The 19-norprogestins can produce these carbohydrate changes and seen to act at the insulin receptor level. Norgestrel, ethynodiol diacetate, and norethindrone alter carbohydrate metabolism, but norgestrel produces the most marked changes. Use of oral contraceptives containing less than 50 microgram of estrogen resulted in fewer metabolic changes than were seen with the drugs containing higher doses of estrogen.

Blood glucose and plasma insulin studies during three months' use of a low-estrogen type oral contraceptive

Blood glucose and plasma insulin levels were measured during an oral glucose tolerance test in 18 women before and after 3 months' use of a low-estrogen oral contraceptive containing 0.035 mg of ethinylestradiol and 0.5 mg of norethindrone. There was no significant change in either of these two metabolic parameters. In addition, the blood pressures and weights of the women were unchanged during that time. Although these are only preliminary data, they are encouraging, for similar studies with higher-dose preparations often showed significant alterations in carbohydrate tolerance.

Circadian variation in plasma prolactin, gonadotropins, and testosterone in diabetic male patients with and without impotence

The circadian variation in plasma levels of prolactin, gonadotropins, testosterone, and glucose were studied in 10 young diabetic male patients. Four patients were asymptomatic without sexual dysfunction and six patients had organic impotence. The results of this study indicate that diurnal levels of luteinizing hormone, follicle-stimulating hormone, prolactin, and testosterone are similar in diabetic patients with and without impotence. During the nocturnal period, a sleep-related increase in plasma prolactin levels was noted in diabetic patients without impotence. In diabetic patients with impotence, plasma prolactin levels were similar during the diurnal and nocturnal periods. These results further support previous findings that diabetic patients with organic impotence do not have abnormal gonadotropin and testosterone levels.

Prospective studies of carbohydrate metabolism in "normal" women using norgestrel for eighteen months

Studies of carbohydrate metabolism were conducted before and after 18 months of daily use of a 0.075-mg norgestrel preparation by 50 "normal" women. Each study involved a 3-hour oral glucose tolerance test. There was a significant increase in the weights of the women over the time of study. In addition, all of the plasma insulin values and all of the blood glucose values were significantly elevated at the 18-month test. All of the control glucose tolerance tests were normal initially, but eight (16%) of the glucose curves were abnormal at the 18-month test. These data suggest a systemic metabolic effect of norgestrel which may play a role in accelerating atherogenesis.

Carbohydrate metabolism with three months of low-estrogen contraceptive use

Prospective studies of carbohydrate metabolism were performed by means of an oral glucose tolerance test in 29 women. The studies were performed before and after 3 months of treatment with an oral contraceptive that contained 0.035 mg of ethinyl estradiol and 0.4 mg of norethindrone. The 24 women with a "normal" control test had no significant alteration in any of their blood glucose and plasma insulin values, except that the fasting glucose level decreased with treatment. Three of these women (12.5%) had a slight deterioration of their glucose curves into a "borderline abnormal" grouping during treatment. There were five women with "borderline abnormal"control glucose curves, and in four of these (80%) the curves returned to "normal" during treatment, whereas one curve stayed "borderline abnormal." These data suggest that this low-estrogen oral contraceptive has minimal short-term adverse effects on the carbohydrate metabolism.

Influence of HLA types on carbohydrate effects of a low-estrogen oral contraceptive

The lymphocyte HLA types were determined for 13 women, who were then separated into a subgroup of those having a "high" risk for insulin-dependent diabetes mellitus (B8, B15, AW30) and a "low-risk" subgroup (B7, BW35). A 3-hour oral glucose tolerance test was conducted on each woman before starting on oral contraceptives (OC) and then 6 months after using them. Both blood glucose and plasma insulin levels were measured. The OC contained 0.035 mg of ethinylestradiol and 0.4 mg of norethindrone. There was a significantly higher 0.5-hour glucose value in the control test in the "high risk" group. There was a significant elevation of the 1-hour plasma insulin value in the 6-month test for the "high-risk" group. The usefulness of the HLA prescreening of women prior to use of OC needs more study.

Biochemical basis for the selection of oral contraceptives

Many specific plasma proteins show dose-related changes when oral estrogens are administered. Large increases in concentration are seen in many important binding proteins, such as the sex hormone-binding globulin, transcortin, the retinol-binding protein, ceruloplasmin, and transferrin. A smaller group of plasma proteins are reduced in amount. These changes are related to altered rates of hepatic synthesis and secretion. As the overall effect of estrogen is one of increased protein synthesis, there is a reduction in the amount of plasma-free amino acids and in the pattern of distribution. Oral contraceptive (OC) users frequently show significant alterations in biochemical tests of vitamin status, at least some of which are related to alterations in plasma proteins. Other biochemical changes associated with OC use include a fasting hyperlipidemia, due mainly to increases in triglycerides, although there is often also a small increase in cholesterol. These changes are due primarily to increases in several lipoprotein fractions and are related mainly to the estrogen component. A deterioration in glucose tolerance occurs in many OC users and is probably induced by both estrogens and progestogens. There is evidence that certain clinical side effects of OCs, such as depression, are associated with specific biochemical changes.

Carbohydrate metabolism and the semen profile: glucose, insulin, and sperm studies

Twenty-seven men attending an infertility clinic received detailed studies of their ejaculate and carbohydrate metabolism. The latter was done using a 3-hour oral glucose tolerance test with a 100-gm glucose load and measuring both blood glucose and plasma insulin levels. There was no significant difference in either the blood glucose or the plasma insulin values between the men with normal sperm counts and those with abnormal sperm counts. These data suggest that mild subclinical states of carbohydrate abnormalities do not routinely alter male fertility.

Carbohydrate metabolism prospectively studied in women using a low-estrogen oral contraceptive for six months

Twenty-four women were prospectively evaluated for their carbohydrate metabolic status before and after six months of using an oral contraceptive containing 0.035 mg ethinyl estradiol and 0.4 mg of norethindrone. At each testing, a 100-gm oral glucose load was administered and blood glucose and plasma insulin values were measured over a three-hour period. Nineteen women with "normal" control tests demonstrated a significant decrease in their fasting glucose values and two of these women (10.5%) had a slight deterioration of their glucose curves. There were no other significant glucose or insulin changes. They had no change in weight and there was a significant reduction in their blood pressure during the treatment time. Five women had "borderline abnormal" control glucose tests, and four of these (80%) improved during the six months of treatment, and two of them (40%) became "normal." Thus, there is no evidence of an adverse effect of this low-estrogen oral contraceptive on carbohydrate metabolism during six months of therapy.

Metabolic and endocrine studies in women using norethindrone acetate implant

Subcutaneously administered implant-D containing 40 mg of Norethindrone acetate in a single silastic implant was offered to 79 subjects who desired spacing of their family. The effect of constant release of steroid from this device on metabolic and endocrine functions was studied. Each subject in the pretreatment state served as her own control. The device was removed at 8 months initially and subsequently at 5-6 months. The clinical acceptability of this method was fairly high. The results reported in this study show that Norethindrone acetate administered in this way did not cause any adverse reactions on endocrine and metabolic functions as gauged by the parameters analysed.

The effects of a once-a-week steroid contraceptive (R2323) on lipid and carbohydrate metabolism in women during three months of use

Forty-four women were prospectively evaluated with a 3-hour oral glucose tolerance test while they used a new weekly oral contraceptive drug, R2323. The blood tests were carried out before the drug was administered and again 3 months after its use. Both blood glucose and plasma insulin levels were measured. In the 40 women with a "normal" control glucose tolerance test, it was found that only the 1-hour blood glucose value was significantly elevated after 3 months of drug use and the plasma insulin values were unchanged. The tests of three of the four women with borderline abnormal to abnormal control test curves converted to normal with 3 months of treatment and that of one remained unchanged. The fasting plasma cholesterol and triglyceride levels were unchanged over the 3 months' time. These results suggest that this steroid contraceptive has no effect on lipid metabolism. It also has minimal adverse effects on normal carbohydrate metabolism and may possibly improve abnormal metabolism.

Effect of estrogen treatment for one year on carbohydrate and lipid metabolism in women with normal and abnormal glucose tolerance test results. Glucose, insulin, growth hormone, triglycerides, and Premarin

A prospective study of the effects of a conjugated estrogen (Premarin, 1.25 mg.) was performed in 36 women over a 1 year period. Each subject received a 3 hour oral glucose tolerance test before starting the medication and another after 1 year of use. The blood glucose levels were similar at five times during the two tests except for a significant elevation of the 1 hour value at the 1 year test. There were no changes in the plasma insulin, growth hormone, or fasting triglyceride levels. These results suggest that the cyclic administration of this estrogen does not alter lipid or carbohydrate metabolism.

Studies of carbohydrate and lipid metabolism in women using the progesterone-T intrauterine device for six months: blood glucose, insulin, cholesterol, and triglyceride levels

A prospective, detailed study of both lipid and carbohydrate metabolism was carried out in 35 women who used a progesterone-T type intrauterine device (IUD). A 3-hour oral glucose tolerance test was performed in each woman before the IUD was inserted and again after 6 months of use. There was no change in the patients' weight or in the fasting glucose, cholesterol, or triglyceride levels. There were significant increases in the 3-hour glucose and the fasting, 0.5-, and 3-hour plasma insulin values in the 6-month tests. These values were less than those found after 6 months of systemic progestogen use, but do suggest some systemic effect of the released progesterone.

The effects of a "low-estrogen" oral contraceptive on carbohydrate metabolism during six months of treatment: a preliminary report of blood glucose and plasma insulin values

A prospective study of carbohydrate metabolism was carried out on seven women by using an oral glucose tolerance stimulation test and measuring blood glucose and plasma insulin values over a 3-hour time period. The test was performed before and after 6 months of treatment with a "low-estrogen" oral contraceptive containing 0.4 mg of norethindrone and 35 micrograms of ethinylestradiol. There was no change in the weight or diastolic blood pressure of the women, but there was a slight elevation of the systolic blood pressure with treatment. There was no significant change in the plasma insulin values or in four of five blood glucose values. The 1-hour blood glucose value was significantly lower after 6 months of treatment. These results suggest that the "low-estrogen" oral contraceptives may reduce the secondary effects on carbohydrate metabolism seen with regular oral contraceptives.