Effect of duration of low-dose oral contraceptive administration on carbohydrate metabolism

Androgenicity of progestins in hormonal contraceptives and the risk of gestational diabetes mellitus

OBJECTIVE

There is some evidence that use of hormonal contraceptives, particularly the more androgenic formulations, can alter a woman's glucose tolerance. We examined the association between hormonal contraceptive use, categorized by the androgenicity of the progestin component, and risk of gestational diabetes mellitus (GDM) in a nested case-control study.

RESEARCH DESIGN AND METHODS

Case (n = 356) and control (n = 368) subjects were selected from a multiethnic cohort of 14,235 women who delivered a singleton live birth between 1 January 1996 and 30 June 1998, who were screened for GDM at 24-28 gestational weeks, and who were members of Kaiser Permanente for at least 5 years before pregnancy. GDM was defined using the National Diabetes Data Group plasma glucose cutoffs. Information concerning hormonal contraceptive use during the 5 years before pregnancy was obtained from medical charts and some pharmacy data.

RESULTS

There was a suggestion that compared with no hormonal contraceptive use, use of a low-androgen hormonal contraceptive before pregnancy was associated with a slight reduction in risk of GDM (odds ratio 0.84 [95% CI 0.58-1.22]), whereas use of a high-androgen hormonal contraceptive was associated with a modest increase in GDM risk (1.43 [0.92-2.22]).

CONCLUSIONS

The effects of hormonal contraceptive use on GDM risk may vary by the androgenicity of the progestin component.

Risk of diabetes mellitus associated with atypical antipsychotic use among Medicaid patients with bipolar disorder: a nested case-control study

STUDY OBJECTIVE

To quantify the risk of diabetes mellitus associated with atypical antipsychotics compared with conventional antipsychotics in managed care Medicaid patients with bipolar disorder.

DESIGN

Retrospective nested case-control study.

DATA SOURCE

Integrated seven-state Medicaid managed care claims database from January 1, 1998-December 31, 2002.

PATIENTS

Two hundred eighty-three patients with diabetes (cases) and 1134 controls matched by age, sex, and the index date on which bipolar disorder was diagnosed.

MEASUREMENTS AND MAIN RESULTS

Cases were defined as those having an International Classification of Diseases, Ninth Revision diagnosis of diabetes or those receiving treatment with antidiabetic drugs. Both case and control patients had at least a 3-month exposure to either conventional or atypical antipsychotic agents or three filled prescriptions related to treatment for bipolar disorder. Of the 283 cases, 139 (49%) received atypical antipsychotics (olanzapine, risperidone, quetiapine, ziprasidone, and clozapine) and 133 (47%) were prescribed conventional antipsychotics. To compare the risk for new-onset diabetes associated with atypical versus conventional antipsychotics, we conducted a Cox proportional hazard regression, in which we controlled for age; sex; duration of bipolar disorder follow-up; use of lithium, anticonvulsants, antidepressants, and other drugs; and psychiatric and medical comorbidities. Compared with patients receiving conventional antipsychotics, the risk of diabetes was greatest among patients taking risperidone (hazard ratio [HR] 3.8, 95% confidence interval [CI] 2.7-5.3), olanzapine (3.7, 95% CI 2.5-5.3), and quetiapine (2.5, 95% CI 1.4-4.3). The risk for developing diabetes was also associated with weight gain (HR 2.5, 95% CI 1.9-3.4), hypertension (HR 1.6, 95% CI 1.2-2.2), and substance abuse (HR 1.5, 95% CI 1.0-2.2).

CONCLUSION

Olanzapine, risperidone, and quetiapine are all associated with development or exacerbation of diabetes mellitus in patients with bipolar disorder. When prescribing therapy for this patient population, metabolic complications such as diabetes, weight gain, and hypertension need to be considered.

Assessment of independent effect of olanzapine and risperidone on risk of diabetes among patients with schizophrenia: population based nested case-control study

OBJECTIVE

To quantify the association between olanzapine and diabetes.

DESIGN

Population based nested case-control study.

SETTING

United Kingdom based General Practice Research Database comprising 3.5 million patients followed between 1987 and 2000.

PARTICIPANTS

19 637 patients who had been diagnosed as having and treated for schizophrenia. 451 incident cases of diabetes were matched with 2696 controls.

MAIN OUTCOME MEASURES

Diagnosis and treatment of diabetes.

RESULTS

Patients taking olanzapine had a significantly increased risk of developing diabetes than non-users of antipsychotics (odds ratio 5.8, 95% confidence interval 2.0 to 16.7) and those taking conventional antipsychotics (4.2, 1.5 to 12.2). Patients taking risperidone had a non-significant increased risk of developing diabetes than non-users of antipsychotics (2.2, 0.9 to 5.2) and those taking conventional antipsychotics (1.6, 0.7 to 3.8).

CONCLUSION

Olanzapine is associated with a clinically important and significant increased risk of diabetes.

Dangerous and common drug interactions in patients with diabetes mellitus

As more medications are made available to the prescriber, the likelihood of drug interactions will increase. The number of drug interactions encountered by the provider treating the patient with diabetes has increased over the past few years because the number of medications used in the management of hyperglycemia has dramatically increased during that time. These interactions are complex but can be predicted.

Occlusive vascular diseases in oral contraceptive users. Epidemiology, pathology and mechanisms

Despite being an unprecedented departure from normal physiology, the combined oral contraceptive is not only highly effective, but it also has a remarkably good safety record. Concerns over safety persist, though, particularly with regard to venous thromboembolism (VTE), stroke and myocardial infarction (MI). Epidemiological studies consistently show an increase in risk of VTE, but the results are more contentious with regard to arterial diseases. Despite 40 years of research, the mechanisms behind these adverse effects are not understood. In this review, we integrate information from published studies of the epidemiology and pathology of the occlusive vascular diseases and their risk factors to identify likely explanations for pathogenesis in oral contraceptive users. Oral contraceptives induce both prothrombotic and fibrinolytic changes in haemostatic factors and an imbalance in haemostasis is likely to be important in oral contraceptive-induced VTE. The complexity of the changes involved and the difficulty of ascribing clinical significance has meant that uncertainty persists. A seriously under-researched area concerns vascular changes in oral contraceptive users. Histologically, endothelial and intimal proliferation have been identified in women exposed to high plasma estrogen concentrations and these lesions are associated with thrombotic occlusion. Other structural changes may result in increased vascular permeability, loss of vascular tone and venous stasis. With regard to arterial disease risk, epidemiological information relating to dose effects and joint effects with other risk factors, and studies of pathology and changes in risk factors, suggests that oral contraceptive use per se does not cause arterial disease. It can, nevertheless, synergise very powerfully with subclinical endothelial damage to promote arterial occlusion. Accordingly, the prothrombotic effects of the oral contraceptive estrogen intervene in a cycle of endothelial damage and repair which would otherwise remain clinically silent or would ultimately progress - in, for example, the presence of cigarette smoking or hypertension - to atherosclerosis. Future work in this area should focus on modification of the effects of established risk factors by oral contraceptive use rather than modification of the supposed risk of oral contraceptive use by established risk factors. Attempts to understand vascular occlusion in oral contraceptive users in terms of the general features of VTE or with reference to atherosclerosis may be limiting, and future work needs to acknowledge that such occlusions may have unique features. Unequivocal identification of the mechanisms involved would contribute considerably to the alleviation of fears over vascular disease and to the development of even safer formulations.

Norplant failure: an adolescent case study and review of the literature

STUDY OBJECTIVE

To alert clinicians to risk factors associated with levonorgestrel implant (Norplant; Wyeth-Ayerst Laboratories, Philadelphia, PA) failures in the adolescent population and discuss alternatives.

DATA SOURCES

Medline search of articles pertaining to the use of levonorgestrel implants in the adolescent population.

STUDY SELECTION

All articles pertaining to the use of levonorgestrel implants in adolescents.

CONCLUSIONS

Levonorgestrel subdermal implants, Norplant, have been successfully used worldwide as contraceptives. Clinical trials suggest that pregnancy rates while using levonorgestrel implants are positively correlated with increased body weight. In addition, pregnancy rates may be higher in women below age 25 years. Finally, patients who report regular menstrual cycles on levonorgestrel implants may be at greater risk for method failure. Consequently, despite its apparent success, levonorgestrel implants have some significant but little-known limitations that should be considered in initial adolescent patient selection, education, and postinsertion medical supervision.

Drug interactions in diabetic patients. The risk of losing glycemic control

Any number of prescription and over-the-counter medications, including diuretics and salicylates, can affect glycemic control in diabetic patients. In addition, patients being treated with either insulin or sulfonylurea risk hypoglycemic coma or death if they ingest large quantities of alcohol. The authors of this article discuss the medications most likely to be a problem and provide lists of agents associated with hypoglycemia and hyperglycemia.

Drug-induced diabetes

The only drugs which commonly cause diabetes during therapeutic use are the anti-hypertensive vasodilator diazoxide, and corticosteroids in high doses such as those used to palliate intracranial tumours. Thiazide diuretics have in the past been used in higher doses than necessary to treat hypertension, and the lower doses now used probably carry only a slight risk of inducing diabetes. The risk from beta-blockers is also quite small, but there is some evidence that thiazides combined with beta-blockers may be more likely to cause diabetes than either drug alone. The combination is probably best avoided in patients with a family history of non-insulin-dependent diabetes. The effect of the low-oestrogen combined oral contraceptive pill seems to be slight, and it presents a risk only to women who have had gestational diabetes. Bodybuilders who take enormous doses of anabolic-androgens can develop impaired glucose tolerance. Several drugs, including theophylline, aspirin, isoniazid and nalidixic acid can cause transient hyperglycaemia in overdosage, but only streptozotocin, alloxan and the rodenticide Vacor are likely to cause permanent diabetes.

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.

Norgestimate: a clinical overview of a new progestin

The efficacy and safety of a new monophasic oral contraceptive, norgestimate/ethinyl estradiol, containing the third-generation progestin, norgestimate (250 micrograms), and ethinyl estradiol (35 micrograms), are reviewed. Norgestimate/ethinyl estradiol demonstrates excellent contraceptive efficacy, with a Pearl index of 0.25. Cycle control is reliable, with a low incidence of breakthrough bleeding and spotting. Because of the minimal androgenicity of norgestimate, norgestimate/ethinyl estradiol has a low impact on carbohydrate and lipid metabolism. It neither reduces the vasodilatory and antiaggregatory prostacyclin nor increases its endogenous antagonist, thromboxane. Norgestimate/ethinyl estradiol has no significant effect on blood coagulation factors. All these characteristics suggest that norgestimate/ethinyl estradiol may be associated with a lower risk of cardiovascular disease than other oral contraceptives currently available. Epidemiologic data, however, are not available, and physicians should be reluctant to prescribe it or any oral contraceptive to patients who have a history of vascular or thrombotic disorders.

Clinical and metabolic considerations of long-term oral contraceptive use

Newer lower dose formulations are associated with an improved cardiovascular disease risk marker profile, which supports their use for longer periods and among older women. Epidemiologic studies of the newer formulations are limited. Without clinical information, an evaluation of the effects of more recent formulations on metabolic risk markers for cardiovascular disease is useful. In a large cross-sectional study, a reduction in the progestin dose and use of alternative progestins substantially reduced the proportion of oral contraceptive users with values associated with an increased risk of cardiovascular disease. No progression in metabolic changes was found by analyzing the effect of the duration of oral contraceptive use. The user's age interacted positively with the oral contraceptive--induced increase in serum triglyceride levels, but there was no interaction of age with the oral contraceptive's effect on oral glucose tolerance, glucose and insulin responses, low-density lipoprotein cholesterol, or high-density lipoprotein subfraction 2 cholesterol levels.

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.

Progestagen-only oral contraceptives: comparison of the metabolic effects of levonorgestrel and norethisterone

A 6-month single-blind study compared the use of a progestagen-only oral contraceptive containing norethisterone 350 micrograms/day (NE 350) with one containing levonorgestrel 30 micrograms (LN 30), to assess the metabolic effects. At the end of 6 months, there were no significant differences between the two groups with respect to plasma cholesterol, lipoproteins including HDL subfractions, triglycerides or glucose concentration. Levels of fibrinogen, plasminogen, Factor VII, Factor X and antithrombin III were also similar. Women changing from a combined oral contraceptive to LN 30 showed a significant fall in Factor X. Mean blood pressure fell on LN 30 by 7/9 mmHg, but the 6-month reading did not differ significantly from that in women on NE 350. Acceptability, and the metabolic effects of the two preparations were similar in this study. Further larger studies are warranted.

Oral contraception in disease states

Oral contraceptives are clearly contraindicated in patients with a history of thromboembolic disease, ischemic heart attack, or cerebral stroke. Patients requiring long-term anticoagulant treatment can be treated with gonadotropin-releasing hormone analogs to prevent ovulation, because ruptured follicles can cause massive intraperitoneal bleeding. Patients with essential hypertension and severe liver diseases should also discontinue treatment 4 weeks before major elective surgery. Migraine and diabetes mellitus are regarded as relative contraindications, depending on the individual situation. Long-term diseases, such as Crohn's disease, epilepsy, and sickle cell anemia, also require individualized consultation.

Effects of a low-dose estrogen-antiandrogen combination (Diane-35) on lipid and carbohydrate metabolism in patients with polycystic ovary syndrome

This study was undertaken in order to evaluate the effect of an oral contraceptive containing 35 micrograms of ethinyl estradiol and 2 mg of cyproterone acetate (Diane-35) on carbohydrate and lipid metabolism in patients with polycystic ovary syndrome (PCOS). Twenty three patients with PCOS were treated with Diane-35 for between 9 and 18 cycles without interruption (a total of 318 treated cycles). Metabolic evaluations, which included measurements of fasting blood glucose, insulin, C-peptide, total cholesterol, triglyceride, total lipids, HDL-cholesterol, LDL-cholesterol and apolipoproteins (Apo A1, Apo A2 and Apo B), were performed before treatment and every 3rd cycle during the treatment period. In the case of 5 women an oral glucose tolerance test (oGTT) was performed before and after the 12th cycle of Diane-35 treatment, with blood samples taken for glucose, insulin and C-peptide measurements. Total cholesterol showed a significant increase after the 6th cycle (p less than 0.001) and reached the mean maximal value after the 9th cycle. A similar increasing trend was observed with LDL-cholesterol, which also reached the maximal mean level after the 9th cycle of treatment (p less than 0.05). There were no significant changes in HDL-cholesterol levels. Significant increases in serum triglyceride (p less than 0.01) and total lipids (p less than 0.001) were observed after the 3rd cycle. Apo A2 concentrations increased significantly after the 6th cycle (p less than 0.001) and showed an increasing trend thereafter. A significant increase was also observed in Apo B concentrations after the 6th cycle but these decreased after the 12th cycle. In spite of these observed increases in serum lipids and lipoproteins, the mean levels remained within the normal range throughout the treatment period. Fasting serum glucose, insulin and C-peptide concentrations did not show any significant changes during the study. Higher insulin and C-peptide responses during the oGTT were observed after the 12th cycle but the differences in the areas under the curve before and after treatment were not significant. A deterioration of blood glucose was observed after treatment with Diane-35, a significant difference in mean values being noted 150 minutes after the glucose overload (p less than 0.005). However, the areas under the curve in blood glucose response before (34.92 +/- 4.12) and after (43.45 +/- 3.61) treatment were not significantly different.(ABSTRACT TRUNCATED AT 400 WORDS)

Clinical aspects of the relationship between oral contraceptives, abnormalities in carbohydrate metabolism, and the development of cardiovascular disease

Although large epidemiologic studies indicated no difference in the frequency of diabetes mellitus in nonusers and everusers of high-dose combination oral contraceptives, other studies had shown an increased risk of impaired glucose tolerance in current users, which is estimated to be roughly twice as frequent as that in nonusers. Women at risk of developing impaired glucose tolerance while receiving high-dose oral contraceptives either had previous gestational diabetes mellitus or were older, obese, or had a positive family history of diabetes mellitus. The tendency to decreased glucose tolerance seems essentially related to the dosage and chemical structure of the progestogen used in oral contraceptives, namely, estrane and particularly gonane progestins. However, increased frequency of impaired glucose tolerance and potentially diabetes mellitus are obviously not linked to the use of the more potent gonane progestins. The use of low-dose oral contraceptives, particularly with reduced progestogen content (such as in the triphasic formulations and last-generation monophasic preparations), is accompanied by a low risk of impaired glucose tolerance, even in previous gestational diabetes mellitus. The mechanism of decreased glucose tolerance in oral contraceptive users is unknown but seems related partially to increased peripheral resistance that is potentially caused by a postreceptor defect in insulin action. Changes in insulin production or metabolic clearance rate are not excluded by recent, sophisticated investigations of carbohydrate metabolism in oral contraceptive users. Impaired glucose tolerance and diabetes mellitus, chronic hyperglycemia, and hyperinsulinemia are believed to increase atherogenic risk either by their direct action or their effects on lipid metabolism. Newer epidemiologic studies now indicate that the incidence of cardiovascular disease in low-dose, low-risk, current oral contraceptive users has been substantially decreased. The use of low-dose oral contraceptives with reduced dosages of better adapted progestogens seems effective in decreasing alterations in carbohydrate metabolism and may thereby contribute to decrease further atherogenic risk in oral contraceptive users.

Low-dose oral contraceptives and carbohydrate metabolism

Combined oral contraceptive use has been associated with increased incidence of impaired and diabetic glucose tolerance. Although increased risk of overt symptoms of diabetes has not been associated with oral contraceptive use, increased risk of coronary heart disease has been consistently demonstrated. Diabetes is associated with increased risk of coronary heart disease, especially in women. Elevated plasma glucose and insulin concentrations are also associated with increased risk of coronary heart disease. Studies of the effects of low-dose oral contraceptives on glucose tolerance test plasma glucose and insulin levels are reviewed. Low-dose combined oral contraceptives induced changes in measures of carbohydrate metabolism in directions consistent with increased risk of coronary heart disease. The magnitude of these changes may depend on the dose and type of progestogen. The clinical implications of these changes are unknown, but it would seem advisable to minimize them where possible.

Carbohydrate metabolic studies during twelve months of treatment with a low-dose combination oral contraceptive

Carbohydrate metabolism was evaluated in twenty healthy women volunteers using a low-dose combination oral contraceptive (OC) containing 30 micrograms of ethinyl estradiol and 500 micrograms of dl-norgestrel by measurement of serum glucose and insulin levels during 3-hour oral glucose tolerance test (OGTT) before and after 3, 6 and 12 months of medication. There were no significant differences in body weight or blood pressure between pretreatment and posttreatment. Fasting serum glucose levels were slightly reduced, though not significantly, during all periods of treatment. But serum glucose levels were increased at 1, 2 and 3 hours in association with high insulin responses during OGTT in all periods of OC therapy, indicating mild to moderate insulin resistance. These data suggest that the low-dose combination OC used in the study exerts alterations on carbohydrate metabolism in women during one year of OC use.

Alterations in carbohydrate metabolism as they apply to reproductive endocrinology

This review has characterized the current state of knowledge of four clinical situations in which an interrelationship of gynecology, endocrinology and carbohydrate metabolism is recognized. The literature contains conflicting descriptions of changes in glucose homeostasis during the menstrual cycle and while using birth control pills. Physiologic changes in receptor number have been demonstrated in each of these situations, so failure to observe differences using glucose tolerance testing may reflect an in vivo homeostatic response to changes in these hormone levels. Thus, in vivo identification of alterations in carbohydrate metabolism induced by endogenous or exogenous steroids may require utilization of models that prevent these homeostatic mechanisms. The association between hyperandrogenism and hyperinsulinism has been better characterized, but the relationship is complicated by the frequent coexistence of obesity. The association may be due to insulin-stimulated ovarian androgen production, and insulin insensitivity may reflect a postreceptor defect. Insulin and its metabolic effects have also been implicated in ovulatory dysfunction in women with diabetes mellitus and identified as a factor affecting all levels of the hypothalamic-pituitary-ovarian axis. A clearer understanding of these relationships and their application to clinical management await further study.

Oral contraceptives and coronary heart disease: modulation of glucose tolerance and plasma lipid risk factors by progestins

Widespread use of oral contraceptive formulations by women throughout their reproductive life has given rise to concerns about the effects of oral contraceptives on risk factors for coronary heart disease. Oral contraceptive-induced changes in both carbohydrate and lipoprotein risk factors may contribute to an increased risk of coronary heart disease. Carbohydrate and lipoprotein risk factors for coronary heart disease are reviewed, and oral contraceptive-induced changes in carbohydrate and lipoprotein metabolism, which may lead to altered risk status for coronary heart disease, are discussed. The importance of methodology in evaluating the results of studies assessing such oral contraceptive-induced changes is stressed. The role of progestins in influencing coronary heart disease risk factors is surveyed, and differences among progestins commonly used in oral contraceptive formulations are discussed. In addition, the effect of various combination oral contraceptives on risk factor status is outlined. Finally, the implications of available evidence for the selection of progestins for oral contraceptive formulations of the future are discussed. Current data indicate that medium- and low-fixed-dose oral contraceptive formulations containing estrogen/norethindrone acetate have less metabolic impact than do comparable levonorgestrel-containing formulations, including multiphasic formulations. Triphasic formulations may have less effect on coronary heart disease risk factors, although data are not yet conclusive. Novel progestins such as desogestrel may also have lesser effects on metabolic functions, but the reduced androgenicity of such compounds may expose women to an increased risk of estrogen-induced hypertriglyceridemia.

Long-term use of an injectable contraceptive: effect of depot-norethisterone oenanthate on carbohydrate metabolism

In order to determine the metabolic effects of long-term use of the injectable contraceptive norethisterone oenanthate, plasma glucose and serum insulin concentrations were studied in two groups of women who had used the method continuously for at least five years. Group 1 comprised 24 subjects, from whom only fasting blood samples were taken. Despite similar plasma glucose concentrations to those of the controls, the subjects had significantly increased serum insulin concentrations (164.5 (39.9) v 120.3 (34.3) pmol/l, p less than 0.01). In addition the insulin:glucose ratios were also significantly increased (34.3 (8.5) v 24.6 (6.7), p less than 0.01), consistent with decreased insulin sensitivity. Group 2 comprised 13 of the original 24 subjects who also had an oral glucose tolerance test. Basal plasma glucose concentrations were similar in the subjects and their controls, whilst the significantly increased insulin:glucose ratios (35.0 (7.7) v 28.7 (5.6), p less than 0.05) were consistent with the results of the larger group. Following oral glucose challenge, plasma glucose concentrations, serum insulin concentrations and insulin:glucose ratios were similar in the subjects and their controls throughout the test. Thus, long-term use of norethisterone oenanthate injections is associated with a decrease in peripheral insulin sensitivity. However, these changes are not associated with any evidence of oral glucose intolerance.

Metabolic effects of oral contraceptives

Combination oral contraceptives (OCs) are probably not an independent risk factor for cardiovascular disease but through their metabolic actions, may partly amplify the effects of known risk factors for cardiovascular disease. This review of the literature and our own data indicate that use of high-dose, progestogen-dominant OCs induces a potentially atherogenic lipoprotein profile (high low-density lipoprotein-cholesterol:high-density lipoprotein-cholesterol ratio), mostly attributable to the antiestrogenic action of the progestogen content of these OCs. In contrast, lower-dose combination OCs with reduced amounts of progestogens and slight estrogen dominance, either monophasic or multiphasic, produce strikingly fewer adverse effects on lipoproteins. Moreover, use of low-dose, as opposed to high-dose, OCs results in almost unchanged glucose tolerance, marginally increased or unchanged insulin and glucagon responses to glucose, and probably unchanged levels and activity of peripheral insulin receptors. Further in-depth studies of low-dose OC formulations are mandatory to ascertain reduced metabolic risk of these OCs.

Sexual dimorphism in adrenergic regulation of hepatic glycogenolysis

The total phosphorylase a plus b of hepatocytes isolated from females and incubated in the absence or presence of estradiol and progesterone at concentrations found in vivo does not vary during the estrous cycle. However, there is a slight but significant influence of the estrous cycle on basal and epinephrine-stimulated phosphorylase a activity, with a nadir being seen on diestrus. The relative contributions of the alpha- and beta-mediated pathways to phosphorylase a activation do not vary with the estrous cycle but are constant at 75 and 56%, respectively, of the response to 5 X 10(-8) M epinephrine. When the epinephrine-stimulated glucose release from glycogen stores in cells from females and males is compared, the release from the female is greater than that from the male, while the alpha-receptor-mediated stimulation in the female is comparable with that in the male. The beta-mediated pathway causes glucose release which averages 45% of that stimulated by epinephrine alone in cells from females. Basal cytosolic free calcium is similar in cells from males and females (142 vs. 149 nM, respectively). The epinephrine-stimulated increase in cytostolic free calcium (Cai) is greater in the male than the female at 10(-6) M (489 vs. 380 nM) but greater in the female than the male at 5 X 10(-9) M (54 vs. 27 nM). The changes in Cai are equivalent at intermediate epinephrine concentrations. When considered with our prior analysis of 45Ca efflux after adrenergic stimulation, this suggests there may be a sexual dimorphism in hepatocyte calcium transport systems. The glucose release for a given increase in Cai is greater in the female than the male probably due to the concomitant action of the beta-mediated increase in cAMP and the alpha-mediated increase in Cai. This supports the conclusion that the beta-mediated component does make a significant contribution to the catecholamine regulation of glycogenolysis in hepatocytes from adult female rats.

Impaired glucose tolerance in women using oral contraceptives: United States, 1976-1980

Based on 75-g oral glucose tolerance test results from the second National Health and Nutrition Examination Survey (1976-1980), women 20-44 years reporting the use of oral contraceptives (OCs) had decreased glucose tolerance compared with women not using OCs in this age group. Estimates of decreased glucose tolerance after adjustment for age and body mass index were 15.4% (95% CI, 7.6-23.2%) in OC users vs 6.3% (95% CI, 4.5-8.1%) in nonusers. Oral contraceptive use was associated with elevations in 1 and 2 hour plasma glucose concentrations. The mean adjusted difference between OC users and nonusers at 1 and at 2 hours postchallenge was 14 and 13 mg/100 ml, respectively. Characteristics of study nonrespondents vs respondents were analyzed to estimate potential bias due to nonresponse. No appreciable biases were found, but this does not rule out the possibility that some bias may exist.

Evaluation of a new triphasic oral contraceptive in private practice

We evaluated the clinical and metabolic effects of a new triphasic regimen developed in the continuing attempt to reduce the dose of estrogen and progestogen in oral contraceptives. A combination of ethinyl estradiol (EE) and levonorgestrel (LNg) was used (six tablets with 30 micrograms EE + 50 micrograms LNg, five tablets with 40 micrograms EE + 75 micrograms LNg, and 10 tablets with 30 micrograms EE + 125 micrograms LNg), also known as Triphasil (Wyeth). In a private practice, 409 subjects participated in 7,286 treatment cycles. Three pregnancies occurred, all due to subject failure. Menstrual regulation was excellent and the incidence of side effects extremely low. Withdrawals from the study for possibly drug-related medical reasons totaled 9.0% through 56 cycles of treatment. Metabolic changes also were evaluated in 14 of these women over a 6-month period. The only statistically significant increase in carbohydrate values occurred at 6 months. The mean glucose level at 30 minutes of the oral glucose tolerance test was above the baseline mean value, but serum insulin levels showed no statistically significant deviation. Lipid values presented are total lipids, total cholesterol, triglycerides, alpha-, beta-, and pre-beta-lipoproteins, and high density and low density lipoprotein cholesterol. There was no statistically significant difference between the mean values at baseline and those during treatment for any lipid variable. These results indicate that this triphasic oral contraceptive has a high degree of efficacy, a low incidence of side effects, excellent cycle control, and high subject compliance, and would seem to indicate a minimal influence on the metabolism of lipids and carbohydrates in the small number of subjects studied.

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.

Weight gain in adolescent and young adult oral contraceptive users

This study analyzed weight gain as a side effect of oral contraceptive use in teens and young adults. A retrospective chart review from 1978 to 1983 was conducted at two family planning clinics. Weight gain over 12 months was compared between females starting oral contraceptive pills and a control group using an IUD or a barrier method. One-hundred thirty-eight charts were included in the oral contraceptive group and 35 in the control group. There was no significant difference between the oral contraceptive group and control group in initial weight and weight after one year of use. Distribution of weight was also similar. There were no significant blood pressure changes. In the oral contraceptive group only five (3.7%) users listed weight gain as a side effect. The results suggest that for many young women who use oral contraceptive pills there is no greater risk of weight gain than for other sexually active young females.

A comparative study of the metabolic effects of injectable and oral contraceptives

The metabolic effects of an injectable contraceptive, Depo-provera (medroxyprogesterone acetate), an oral contraceptive pill containing 50 micrograms ethinyl estradiol and 500 micrograms norgestrel and a control group (not on contraceptives) were compared in 3 groups, each comprising 32 women. The subjects were matched for race, age and parity. Mean duration of treatment was 41.7 +/- 18.3 months for Depo-provera and 59.6 +/- 29.0 months for the pill group. Glucose tolerance was impaired in both treatment groups. The combination pill showed more changes in both glucose tolerance and insulin response. Lipid levels remained unchanged in both treatment groups.

Oral glucose tolerance and the potency of contraceptive progestins

Two-hour oral glucose tolerance test results from the Walnut Creek Contraceptive Drug Study, a 10-year prospective follow-up study on the metabolic and medical effects of the "pill," were analyzed to determine the contribution of six progestins and synthetic estrogen to an observed decrease in glucose tolerance. Glucose tolerance data and specific oral contraceptive formulation data were obtained for 354 oral contraceptive users and 1732 nonusers. Multiple linear regression analyses, using age, body mass index, and specific progestin and estrogen dosages as independent variables, were undertaken to define dose-response relationships between the contraceptive steroids and fasting, 1-hr and 2-hr glucose values. The results of these analyses were consistent with the observation that the mean 1- and 2-hr values were higher in users of the "pill." The 16% prevalence of impaired glucose tolerance in pill users was substantially higher than that of 8% in the nonusers. Examination of the regression coefficients suggested that one progestin (norgestrel) was more metabolically "potent" than the others. The remaining progestins appeared to have either a modest or no metabolic effect, in terms of 1- and 2-hr glucose values. Synthetic estrogens were shown not to be related to measures of glucose tolerance.

Reexamining the oral contraceptive issues

Oral contraceptives have been in use since the 1960s. Over the past 20 plus years, the risks and benefits of oral contraceptives have captured the attention of the press and the public. According to current data, oral contraceptives seem to pose the greatest risk for women in their 40s who smoke cigarettes. They have the least risk and greatest benefit for young women, especially nonsmokers. This article focuses on a reexamination of the issues. Are oral contraceptives safe? If so, for whom? How can risk be predicted? What are noncontraceptive benefits? Implications for practice and for the future of oral contraceptives research are presented.

The effects of cyproterone acetate and ethinyl oestradiol on carbohydrate metabolism

Carbohydrate metabolism was studied in a group of 66 women, taking cyproterone acetate (CA) and ethinyloestradiol (EO) as anti-androgen therapy for the treatment of hirsutism and/or acne. A reverse sequential treatment cycle was used and women were studied in two groups: the first when taking the combination of CA and EO during the first 12 days of the treatment cycle, and the second taking EO alone during days 13 to 22. The combination reduced fasting plasma glucose and raised fasting plasma insulin concentrations. There was deterioration of glucose tolerance with increased plasma insulin concentrations and these effects were progressive with time. The plasma insulin response to intravenous tolbutamide was increased by 50% but there was no accompanying change in the glucose nadir as compared with controls. These results show that the combination of CA and EO causes insulin resistance. Plasma C-peptide concentrations following oral glucose were unchanged compared with controls. This shows that the observed hyperinsulinaemia was due to a reduction of hepatic uptake of insulin rather than its increased secretion. We propose that these effects are due to a CA-induced elevation of fasting plasma insulin resulting in downregulation of hepatic insulin receptors with subsequent induction of insulin resistance and impairment of hepatic insulin uptake. C-peptide concentrations following i.v. tolbutamide were significantly higher on treatment with CA and EO than in controls indicating increased pancreatic secretion of insulin. Tests carried out while patients were taking EO alone showed impairment of glucose tolerance only with no change in insulin levels. There was an increase in plasma insulin in response to tolbutamide but this was not significant. We conclude that these results are explained by a reduced but persisting effect of CA.

Oral contraceptive use: prospective follow-up of women with suspected glucose intolerance

593 women from a cohort of 8,652 healthy women failed a 1-hr glucose screening test. These 593 women with suspected glucose intolerance were classified as normal or as having impaired glucose tolerance (IGT) or diabetes mellitus (DM) after an oral standard glucose tolerance test (SGTT) and were followed over a mean 8.55 years. No permanent change in glucose status as a result of oral contraceptive use was found in an analysis for impaired glucose tolerance, diabetes mellitus, diabetic symptoms, or use of oral agents and/or insulin. Increased glucose intolerance was observed for women who were older, had a positive family history of diabetes, or were of greater relative weight. Diabetic symptoms correlated most closely with the onset of persistent fasting hyperglycemia.

Metabolic effects of two triphasic formulations containing ethinyl estradiol and dl-norgestrel

The metabolic effects of two triphasic oral contraceptive (OC) preparations containing dl-norgestrel (dlN) and ethinyl estradiol (EE) were studied in young women. The marked difference in the two preparations was in the progestogen content, allowing the study of the metabolic effects of high and low progestogen in oral contraception. The results suggest that high progestogen increases serum sodium, potassium, blood urea nitrogen, creatinine, total protein, albumen, and lactic dehydrogenase. An increase in aspartate transaminase and a decrease in alkaline phosphatase were probably estrogen-related. High progestogen significantly reduced the fasting blood glucose levels (p less than .001). Both preparations significantly increased the levels of cholesterol and triglycerides in women who had not taken OCs for 3 or more months, and with the low progestogen preparation these increases are dissimilar to the effects reported in the triphasic preparations containing levonorgestrel.

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 effect of progestins in combined oral contraceptives on serum lipids with special reference to high-density lipoproteins

Fasting serum lipids were measured in a group of 293 women desirous of using oral contraceptives (OCs) and 536 women who had been taking five varieties of OCS for many months before being tested. Parameters studied were serum cholesterol, triglyceride, high-density lipoprotein (HDL), the two main subfractions of HDL, namely, HDL2 and HDL3, and the ratio of HDL2 cholesterol to low-density lipoprotein (LDL) cholesterol. Studies of these five groups of women enabled us to compare the effect of varying amounts of levonorgestrel with norethindrone and to study the effects of estrogen combined with these progestins. The levonorgestrel-containing pills and the progestin-only OC significantly depressed HDL2 cholesterol levels and the ratio of HDL2 to LDL cholesterol.