Triphasic oral contraception: metabolic effects in normal women and those with previous gestational diabetes

U.S. Medical Eligibility Criteria for Contraceptive Use, 2024

The 2024 U.S. Medical Eligibility Criteria for Contraceptive Use (U.S. MEC) comprises recommendations for the use of specific contraceptive methods by persons who have certain characteristics or medical conditions. These recommendations for health care providers were updated by CDC after review of the scientific evidence and a meeting with national experts in Atlanta, Georgia, during January 25-27, 2023. The information in this report replaces the 2016 U.S. MEC (CDC. U.S. Medical Eligibility Criteria for Contraceptive Use, 2016. MMWR 2016:65[No. RR-3]:1-103). Notable updates include 1) the addition of recommendations for persons with chronic kidney disease; 2) revisions to the recommendations for persons with certain characteristics or medical conditions (i.e., breastfeeding, postpartum, postabortion, obesity, surgery, deep venous thrombosis or pulmonary embolism with or without anticoagulant therapy, thrombophilia, superficial venous thrombosis, valvular heart disease, peripartum cardiomyopathy, systemic lupus erythematosus, high risk for HIV infection, cirrhosis, liver tumor, sickle cell disease, solid organ transplantation, and drug interactions with antiretrovirals used for prevention or treatment of HIV infection); and 3) inclusion of new contraceptive methods, including new doses or formulations of combined oral contraceptives, contraceptive patches, vaginal rings, progestin-only pills, levonorgestrel intrauterine devices, and vaginal pH modulator. The recommendations in this report are intended to serve as a source of evidence-based clinical practice guidance for health care providers. The goals of these recommendations are to remove unnecessary medical barriers to accessing and using contraception and to support the provision of person-centered contraceptive counseling and services in a noncoercive manner. Health care providers should always consider the individual clinical circumstances of each person seeking contraceptive services. This report is not intended to be a substitute for professional medical advice for individual patients; when needed, patients should seek advice from their health care providers about contraceptive use.

Contraceptive Options Following Gestational Diabetes: Current Perspectives

Gestational diabetes mellitus (GDM) complicates approximately 7% of pregnancies in the United States. Along with risk factors related to pregnancy, women with a history of GDM also have an increased risk of developing type 2 diabetes mellitus later in life. These women require special consideration when discussing contraception and other reproductive health issues. GDM carries a category 1 rating in the US Medical Eligibility Criteria for all contraceptive methods, which supports safety of the various methods but does not account for effectiveness. Contraceptive options differ in composition and mechanisms of action, and concerns have been raised about possible effects of contraception on metabolism. Clinical evidence is limited to suggest that hormonal contraception has significantly adverse effects on body weight, lipid, or glucose metabolism. In addition, the majority of evidence does not suggest a relationship between development of type 2 diabetes mellitus and use of hormonal contraception. Data are limited, so it is challenging to make a broad, general recommendation regarding contraception for women with a history of GDM. A woman’s history of GDM should be considered during contraceptive counseling. Discussion should focus on potential medical comorbidities and the implications of GDM on future health, with special consideration of issues including bone health, obesity, cardiovascular disease, and thrombosis risk. Providers must emphasize the importance of reliable, highly effective contraception for women with GDM, to optimize the timing of future pregnancies. This approach to comprehensive counseling will guide optimal decision-making on contraceptive use, lifestyle changes, and planning of subsequent pregnancies.

The effects of hormonal contraceptives on glycemic regulation

A number of side effects have been linked to the use of hormonal contraceptives, among others, alterations in glucose levels. Hence, the objective of this mini-review is to show the main effects of hormonal contraceptive intake on glycemic regulation. First, the most relevant studies on this topic are described, then the mechanisms that might be accountable for this glycemic regulation impairment as exerted by hormonal contraceptives are discussed. Finally, we briefly discuss the ethical responsibility of health professionals to inform about the potential risks on glycemic homeostasis regarding hormonal contraceptive intake.

Diabetes and pregnancy: an endocrine society clinical practice guideline

OBJECTIVE

Our objective was to formulate a clinical practice guideline for the management of the pregnant woman with diabetes.

PARTICIPANTS

The Task Force was composed of a chair, selected by the Clinical Guidelines Subcommittee of The Endocrine Society, 5 additional experts, a methodologist, and a medical writer.

EVIDENCE

This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system to describe both the strength of recommendations and the quality of evidence.

CONSENSUS PROCESS

One group meeting, several conference calls, and innumerable e-mail communications enabled consensus for all recommendations save one with a majority decision being employed for this single exception.

CONCLUSIONS

Using an evidence-based approach, this Diabetes and Pregnancy Clinical Practice Guideline addresses important clinical issues in the contemporary management of women with type 1 or type 2 diabetes preconceptionally, during pregnancy, and in the postpartum setting and in the diagnosis and management of women with gestational diabetes during and after pregnancy.

Diabetes and oral contraception

The prevalence of diabetes mellitus is increasing dramatically worldwide, resulting in more and more women of reproductive age being affected by either type 1 or type 2 diabetes. Management of contraception is a major issue due to the specific risks associated with pregnancy and those potentially induced by hormonal contraceptives in diabetic women. This review emphasizes the urgent need to improve the use of contraception in women with diabetes. There is no consistent evidence that combined oral contraceptives significantly influence the risk of developing diabetes, even in women with a history of gestational diabetes. Furthermore, although data from specific studies remain sparse, no worsening effect has been reported in diabetic women, either in glycemic control or on the course of microvascular complications. Thus, the use of estroprogestive pills is now recognized as a safe and effective option for preconception care of women with uncomplicated diabetes. According to recent guidelines, these contraceptives must be avoided in case of associated cardiovascular risk factors, cardiovascular disease or severe microvascular complications such as nephropathy with proteinuria or active proliferative retinopathy. Prescription of combined hormonal contraception in type 2 diabetic women must also be considered with caution due to a frequent association with obesity and vascular risk factors which increase both thromboembolic and arterial risks. Thanks to their metabolic and vascular safety profile, progestin-only contraceptives, as well as non-hormonal methods, represent alternatives according to patient wishes.

Hormonal Contraception and Diabetes

Women with gestational diabetes mellitus are at increased risk for developing diabetes mellitus (DM), mainly type 2 DM, as well as metabolic syndrome. The presence of subsequent pregnancies increases the risk. In addition, pregnancy in patients with type 1 and type 2 DM also elevates the risk of morbidity and mortality for both mothers and offspring. Thus, all women with pre-existing type 1 or type 2 DM should receive preconception care to optimize glycemic control (HbA1c ≤ 6%). In those cases with macrovascular or microvascular complications, family planning is even more important in order to avoid the risk of aggravation of such complications associated with a new pregnancy. The present review analyzes the metabolic and cardiovascular repercussions of hormone contraception in non-diabetic women as well as in type 1 and type 2 DM patients with and without macrovascular and microvascular complications. Finally, the recommendations pertaining to hormonal contraceptive methods for women with diabetes are summarized.

Divergent effects of a combined hormonal oral contraceptive on insulin sensitivity in lean versus obese women

OBJECTIVE

To evaluate the effects of a commonly used combined hormonal oral contraceptive (OC) on carbohydrate metabolism in obese as compared with lean women.

DESIGN

6-month prospective study.

SETTING

Clinical research center at an academic medical center.

PATIENT(S)

Premenopausal nondiabetic women with body mass index <25 kg/m(2) (n = 15) or >30 kg/m(2) (n = 14).

INTERVENTION(S)

Ethinyl estradiol (35 μg) and norgestimate (0.18/0.215/0.25 mg) for 6 cycles.

MAIN OUTCOME MEASURE(S)

Insulin sensitivity by frequent sampling intravenous glucose tolerance test; other indices of insulin sensitivity (homeostatic model assessment of insulin sensitivity index [ISI HOMA], the Matsuda index); fasting lipid panel.

RESULT(S)

Insulin sensitivity changed from 6.62 ± 3.69 min(-1)/mIU/L (baseline) to 8.23 ± 3.30 min(-1)/mIU/L (6 months) in lean women, and from 4.36 ± 2.32 to 3.82 ± 2.32 min(-1)/mIU/L in obese women. Divergent effects on insulin sensitivity were also observed with ISI HOMA and the Matsuda index. Low-density lipoprotein increased by approximately 20 mg/dL in both the lean and obese groups.

CONCLUSION(S)

Lean and obese women exhibit differential changes in insulin sensitivity when given 6 months of a commonly used oral contraceptive. The mechanisms of these differences and whether these divergent effects persist in the long term require further investigation.

Managing women with gestational diabetes mellitus in the postnatal period

Guidelines for management of women with a history of gestational diabetes mellitus (GDM) in the postpregnancy period have lagged behind the recognition that this is an important time for medical intervention. However, in the past decade, the evidence-base for screening algorithms, contraceptive management, diabetes prevention strategies and implications for offspring has expanded. In this review, we discuss current recommendations for managing women with GDM in the postnatal period, with particular attention to postpartum diabetes screening, prevention of future glucose intolerance and family planning.

A longitudinal study of lipids and blood pressure in relation to method of contraception in Latino women with prior gestational diabetes mellitus

OBJECTIVE

To investigate the effect of nonhormonal contraception (NHC), combination oral contraception (COC), and depo-medroxyprogesterone acetate (DMPA) on lipids and blood pressure in women with recent gestational diabetes mellitus (GDM).

RESEARCH DESIGN AND METHODS

An observational cohort of 972 nondiabetic, normotensive, postpartum Latino women who elected NHC (n = 448), COC (n = 430), or DMPA (n = 94) were followed for at least one subsequent metabolic evaluation on the same contraception. Baseline and follow-up measures included glucose tolerance testing, fasting serum LDL and HDL cholesterol, triglycerides, and systolic (SBP) and diastolic (DBP) blood pressure. Patterns of changes in lipids and blood pressure were evaluated by comparing slopes over follow-up time using random coefficient linear mixed-effects models.

RESULTS

Median follow-up times were 20, 12, and 11 months in the NHC, COC, and DMPA groups. The DMPA users gained significantly more weight (4.3 +/- 6.9 kg/year) compared with NHC and COC users (1.2 +/- 4.7 and 0.7 +/- 6.0 kg/year, respectively; P < 0.0001). Patterns of change in LDL cholesterol, triglycerides, and DBP were not significantly different among groups. HDL cholesterol change differed only between COC and NHC groups (adjusted slopes: 1.0 vs. -1.6 mg x dl(-1) x year(-1), respectively; P < 0.0001). SBP change differed only between COC and DMPA groups (adjusted slopes: 1.3 vs. -1.7 mmHg/year, respectively; P = 0.01).

CONCLUSIONS

These results, derived predominantly from the initial 1-2 years of treatment in Hispanic women, demonstrate that DMPA was associated with greater weight gain than NHCs or COCs. Other differences in blood pressure and lipid effects were very small. These findings should be taken into account when advising women with recent GDM about their contraceptive choices.

After Pregnancy Complicated by Diabetes: Postpartum Care and Education

The postpartum period in women with pregestational or gestational diabetes allows the physician and mother to switch from intensive medical and obstetric management into a proactive and preventive mode, and to jointly develop a reproductive health plan. The woman's individual needs regarding contraception and breastfeeding, an appropriate diet to achieve healthy weight goals, the medical management of diabetes, daily exercise, and future pregnancy planning must be considered. Essential is the active participation of the woman, who, through education, gains an understanding of the far-reaching effects her active participation will have on her subsequent health, her newborn child's health, and possibly that of her future children.

Effects of oral contraceptives on glucose flux and substrate oxidation rates during rest and exercise

We examined the effects of oral contraceptives (OC) on glucose flux and whole body substrate oxidation rates during rest (90 min) and two exercise intensities [60-min leg ergometer cycling at 45 and 65% peak O(2) uptake (Vo(2 peak))]. Eight healthy, eumenorrheic women were studied during the follicular and luteal phases before OC and the inactive and high-dose phases after 4 mo of a low-dose, triphasic OC. Subjects were studied in the morning 3 h after a standardized (308 kcal) breakfast. There were significant reductions in glucose rates of appearance and disappearance during exercise of both intensities with OC but not rest. There were no phase effects on substrate oxidation during rest or exercise. These results are interpreted to mean that, in women fed several hours before study, 1) OC decreases glucose flux, but not overall carbohydrate and lipid oxidation rates during moderate-intensity exercise; and 2) synthetic ovarian hormone analogs in the doses contained in OC have greater metabolic effects on glucose metabolism during exercise than do endogenous ovarian hormones.

Postpartum care of the woman with diabetes

The postpartum period in women with diabetes or GDM allows both the physician and mother to relax from the intensive medical and obstetric management that has permitted, in most cases, a successful and joyous outcome. The role of the physician, however, must switch to a proactive and preventive mode to formulate a reproductive health plan for women with diabetes and GDM. The plan should be individualized to address glycemic management and surveillance, nutritional management, contraception prescription, future pregnancy planning, and lifestyle changes. Essential to the development of a reproductive health plan is the active participation of the patient, who through education gains an understanding of the far-reaching effects her active participation will have on her subsequent health and possibly on that of her future children.

Modification of plasma insulin-like growth factors and binding proteins during oral contraceptive use and the normal menstrual cycle

OBJECTIVE

Sex steroid regulation of the insulin-like growth factor axis is a subject of contention. We examined the effect of combined oral contraceptives and investigated the cyclic variations in the insulin-like growth factor axis.

STUDY DESIGN

Fasting blood samples were taken from 9 women receiving oral contraceptives, 10 women receiving no medication, and 10 male subjects.

RESULTS

In women receiving oral contraceptives, insulin-like growth factor binding protein 1 remained highly phosphorylated and levels were acutely increased by sex steroid treatment (305 +/- 110 microg/L on day 14 of the cycle [medication phase] vs 118 +/- 70 microg/L during the medication-free period, P <.03). In women receiving no medication, insulin-like growth factor binding protein 1 levels were significantly lower (69 +/- 50 microg/L on day 14 of the menstrual cycle, P <.001) and varied cyclically, with a rise in the late-secretory phase that coincided with the appearance of nonphosphorylated and less phosphorylated insulin-like growth factor binding protein 1 isoforms. Compared with those in untreated women and in men, insulin-like growth factor I levels were decreased in women receiving oral contraceptives (405 +/- 104 ng/mL in untreated women and 330 +/- 28 ng/mL in men vs 287 +/- 73 ng/mL in women receiving oral contraceptives, P <.004). Oral contraceptive use had no effect on insulin-like growth factor II levels, and neither insulin-like growth factor I nor insulin-like growth factor II showed cyclic variation.

CONCLUSION

The bioavailability of insulin-like growth factor I is reduced in users of oral contraceptives. This may contribute to the metabolic changes observed in such subjects.

Contraception in diabetic women

Contraceptive prescription in diabetic women with current diabetic mellitus (type I or type II) or in prediabetic women with previous gestational diabetes mellitus must consider the specific metabolic effects and risks in diabetic women. This article addresses these issues, enabling the practitioner to develop individually tailored contraceptive programs to meet the changing needs and demands of the reproductive-aged diabetic woman. If focuses on the most efficacious, reversible option available--hormonal methods and intrauterine devices--both of which have been controversial for diabetic women.

Biochemical effects in women following one year's exposure to a new triphasic contraceptive--I. chemistry profiles

1. Thirty-nine nonsmoking women, 14 who had never used oral contraceptives and 25 who had a prior history of contraceptive use were placed on a 1-year regimen of oral triphasic contraception containing a new progestin. 2. Biochemical determinations of 21 different variables were made at baseline, 3 months, 6 months, and 12 months of exposure. 3. Most of the significant changes were in those women with no prior exposure to contraceptives. 4. Thyroxine increased and T3 decreased, as did urinary cortisol. No changes were noted in the CBC, hematocrit, or platelet count. Slight increases in cholesterol and triglycerides resulted, with small nonsignificant increases in LDL also occurring; this increase was also noted for HDL. 5. The experimental contraceptive seems to have a very minimal influence on chemistry profiles, suggesting a favorable biochemical response to the progestin.

New progestogens in oral contraception

The major developments in combined oral contraceptives (COCs) have been a reduction in the total dose of both the oestrogen and progestogen administered per cycle and the introduction of new progestogens which are claimed to be more 'selective' than the older ones. This review examines in detail the clinical efficacy of the new COCs, where possible in comparison with those containing levonorgestrel or norethisterone, and their pharmacological effect on carbohydrate and lipid metabolism, haematological factors, pituitary-ovarian function and serum protein and androgen concentrations. Based mainly on the pharmacological evidence, the newer COCs are an improvement over the older low-dose formulations and are clearly preferable to the high-dose ones. However, the older low-dose COCs, despite many years of use, have not resulted in a high incidence of adverse effects. The increasing use of the new COCs, as evidenced by their increasing market share throughout Europe, does indicate that they have been well accepted in clinical practice.

Effect of the different phases of the menstrual cycle and oral contraceptives on athletic performance

The female athlete, during her reproductive years, has a complex and ever-changing milieu of female steroid hormones, whether it is the endogenous variations in estradiol and progesterone of a regular menstrual cycle, or the exogenous synthetic hormones of the oral contraceptives. Both estrogens and progestins have individual, interactive and sometimes opposing physiological actions with potential implications for the exercising female. In retrospective surveys on the menstrual cycle and performance, from 37 to 63% of athletes did not report any cycle 'phase' detriment, while 13 to 29% reported an improvement during menstruation. The best performances were generally in the immediate postmenstrual days, with the worse performances during the premenstrual interval and the first few days of menstrual flow. However, this type of study has an inherent built-in bias, and is further limited by the lack of substantiation of cycle phase. Many of the women studied associated premenstrual symptoms, such as fluid retention, weight gain, mood changes, and dysmenorrhoea with performance decrement. Such factors have also been causally linked with an increase in traumatic musculoskeletal injuries during the premenstrual and menstrual period. Neuromuscular coordination, manual dexterity, judgement and reaction time for complex tests have been shown to be adversely affected in women with premenstrual syndrome or symptoms, but confounding variables may include nutrition status and blood sugar levels. In addition, not all women suffer to the same level with premenstrual symptoms. Fluctuations in many physiological functions occur throughout the normal menstrual cycle. Results of early studies are difficult to interpret owing to the small numbers of women studied, wide range of fitness levels, and variability in the definitions of cycle phase. Nevertheless, investigators did not document any significant changes in measures of athletic performance as a function of timing of testing during the menstrual cycle. Swimmers have shown a premenstrual worsening of performance times, with improvement during the menstrual phase and on the eighth day of the cycle. An increase in perceived exertion was noted premenstrually and during the early menstrual stage with very intense exercise. In cross-country skiers, the best times were recorded in the postovulatory and postmenstrual phases, prompting the recommendation that training loads be selected according to cycle phase to achieve maximum benefit. Investigations using estradiol and progesterone levels as a confirmatory index of ovulation have not generally found significant differences across the cycle in either maximal or submaximal exercise responses, although a slight decrease in aerobic capacity during the luteal phase has been reported.(ABSTRACT TRUNCATED AT 400 WORDS)

Contraception for women with diabetes: an update

Today several effective contraceptive methods are available for women with IDDM. Contraceptive guidance as part of the pre-pregnancy counselling needs to be more widely implemented by general practitioners and in non-specialized obstetrical and gynaecological departments. Women with diabetes are generally well motivated, and thus the barrier methods may prove both acceptable and reliable contraceptive agents for some of these women. When, however, a high risk of user failure can be predicted, the IUD or hormonal contraception may be the only reversible alternative. According to our findings, IUDs can be recommended without reservation to women with IDDM. In women with previous GDM it seems that low dose oral contraceptive compounds may be administered without running the risk of inducing glucose intolerance, but long-term results are still unavailable. Natural oestrogens may be administered in combination with a progestogen for a limited period as an efficient and acceptable mode of contraception in women with IDDM without any concomitant adverse effects on diabetic control. From our investigations it also appears that short-term administration of combined low dose OCs containing the traditional progestogens (e.g. norethisterone or levonorgestrel) or the new gonane progestogens (e.g. gestodene) does not alter glycaemic control in women with IDDM. Similarly, these compounds do not cause any significant changes in lipid/lipoprotein levels during short-term treatment, although the intake of monophasic ethinyloestradiol/norethisterone preparations may result in higher triglyceride levels and tends to increase lipid levels more than triphasic ethinyloestradiol/levonorgestrel compounds. The results from our clinic have shown that OCs can be safely recommended at pre-conception counselling so that women with diabetes can obtain both optimal glycaemic control and efficient spacing of their pregnancies.

Effect of low-dose oral contraceptives on carbohydrate and lipid metabolism in women with recent gestational diabetes: results of a controlled, randomized, prospective study

Women with recent gestational diabetes mellitus were randomly assigned to one of two low-dose oral contraceptives to evaluate the effect of low-dose oral contraceptives on carbohydrate and lipid metabolism. A cohort of similar women requesting a non-oral-contraceptive method served as controls. The two oral contraceptives studied were ethinyl estradiol (0.035 mg)-norethindrone (0.40 mg) and ethinyl estradiol (0.030 to 0.040 mg)-levonorgestrel (0.050 to 0.125 mg). A 75 gm, 2-hour oral glucose tolerance test and a fasting lipid profile (total cholesterol, triglyceride, high- and low-density lipoprotein cholesterols) were performed at entry, after 3 months, and after 6 to 13 months of treatment. The prevalence of diabetes at 6 to 13 months (27/156 patients) was not significantly different between groups (non-oral-contraceptive group, 17%; ethinyl estradiol-norethindrone, 15%; ethinyl estradiol-levonorgestrel, 20%). When examined by prior gestational diabetes mellitus class, diabetes mellitus was present in 7% of prior class A1 and 29% of women with prior class A2 disease (p less than 0.001). Mean cholesterol and low-density lipoprotein cholesterol levels were significantly improved in all three groups at 3 months and at 6 to 13 months, whereas triglycerides remained unchanged. There were no differences in cholesterol, low-density lipoprotein cholesterol, or triglycerides levels between the groups. After 6 to 13 months, there was a significant increase in high-density lipoprotein cholesterol in the ethinyl estradiol-norethindrone group compared with the ethinyl estradiol-levonorgestrel and non-oral-contraceptive groups.

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.

Effects of oral contraceptives on carbohydrate and lipid metabolisms in a healthy population: the Telecom study

In a cross-sectional study that aimed to identify risk factors for diabetes, 1290 consecutive, healthy, nonpregnant women of child-bearing age were examined in a center for preventive medicine. An in-depth interview about menses, use of oral contraceptives, and menopause was performed. Plasma glucose at fasting and 2 hours after a 75 gm glucose load, glycated hemoglobin A1c, fasting plasma insulin, total plasma cholesterol, and triglycerides were measured. Compared with nonusers taking no progestogens, oral contraceptive users (n = 431; 33.4%) were younger (p less than 0.001) and leaner (p less than 0.001). After adjustment for age and body mass index, oral contraceptive users had higher 2-hour plasma glucose (p less than 0.001), higher fasting plasma insulin (p less than 0.01), and higher triglycerides levels (p less than 0.01). Fasting plasma glucose, glycated hemoglobin A1c, and total cholesterol did not significantly differ between the two groups. In relation to dosage and types of steroid components, few differences have been found between high-dose and low-dose oral contraceptives or according to the estrogen-progestogen balance of the preparations. Use of oral contraceptives appears to induce an increase of insulin-resistance markers, which have recently been cited as risk factors for ischemic vascular diseases. These markers should be carefully monitored in oral contraceptive users.

Mechanism of action of oral contraceptives on carbohydrate metabolism at the cellular level

Although the available scientific data on the undesired metabolic effects of sex steroids have accumulated rapidly, most are of a descriptive nature, and only a few studies elucidate the impact at the cellular level and the possible interrelationship between different metabolic systems. This review summarizes the influence of different contraceptive steroid combinations on glucose metabolism and points to the possible mechanisms behind a disturbance of the euglycemic homeostasis with a concomitant change in lipid metabolism. Today the general concept is that the influence of combined sex steroid products on glucose metabolism is mainly caused by the progestogen components, although artificial estrogens may act synergistically. The diabetogenic effects of the progestogens make it important to consider the development during the last decade of the new more selective progestogens of the gonane type. From recent studies it seems, however, that intake of contraceptive combinations of ethinyl estradiol in combination with these types of gonanes, such as desogestrel and gestodene, may also be accompanied by increased insulin resistance, specifically, a hyperinsulinemic response to a glucose challenge despite unchanged glucose values compared with a baseline test. This is similar to observations made with combinations of ethinyl estradiol and other more traditional types of progestogens of the gonane and estrane type. It is conceivable that the diabetogenic effects of the progestogens are caused by a change in insulin receptor binding or a postreceptor defect in the cellular insulin action. The clinical implications of the diabetogenic effects of the sex steroids are hard to interpret, but more long-term exposure of arterial tissue to elevated concentrations of glucose and insulin results in inhibition of lipolysis and synthesis of cholesterol and triglycerides, which result in the development of lipid-filled lesions--fatty streaks--similar to those of early atherosclerosis.

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.

Oral contraceptives, insulin resistance and ischemic vascular disease

From a large prospective study on diabetes risks, 1112 professionally active, non-menopausal, non-pregnant, healthy women were cross-sectionally analysed according to their use of oral contraception. After adjustment for age, weight and diabetes risk factors, those taking the pill, compared to those who did not, had significantly higher fasting serum insulin, triglycerides and 2-h 75 g OGTT blood glucose levels. The insulin-resistance markers which have recently been cited as ischemic vascular disease risk factors should be carefully monitored in pill users.

Triphasic Randomized Clinical Trial: Comparison of effects on carbohydrate metabolism

One hundred thirty women were randomly assigned to treatment with one of three triphasic oral contraceptives and 43 women using nonhormonal methods served as controls for a 6-month study of the metabolic effects of these formulations. One of the oral contraceptives contained ethinyl estradiol and levonorgestrel, and the other two contained ethinyl estradiol and norethindrone. Compared with pretreatment assessment, all three triphasic oral contraceptives produced small increases in the mean plasma glucose levels that were statistically significant but clinically unimportant. No subjects had abnormal glucose response curves in glucose tolerance test results. Compared with pretreatment assessment, all of the oral contraceptive preparations produced small increases in the mean insulin levels at 3 months but not at 6 months. Overall there were no statistically significant differences among the three formulations in their effects on carbohydrate metabolism as measured by glucose or insulin levels after 6 months of treatment.

Clinical aspects of three new progestogens: desogestrel, gestodene, and norgestimate

Three new 19-nortestosterone progestogens, which are chemically related to levonorgestrel, are now clinically available in combination oral contraceptives in Europe. Desogestrel and norgestimate must be transformed to metabolites for all or part of their biologic activity; gestodene is active in its original form. Compared with present low-dose monophasic and triphasic levonorgestrel formulations, the new combinations appear to be equivalent in efficacy and type and frequency of side effects. Cycle control may be slightly improved with the gestodene preparation and somewhat poorer with the desogestrel regimen. As with the present triphasics, most changes reported in coagulation indexes for the new combinations remained within normal limits, as did changes in carbohydrate and lipid metabolism. There is no present evidence that either the norgestimate or aesogestrel formulation provides a clinical improvement over the levonorgestrel triphasic. In the gestodene combination, the progestogen's increased biologic activity allows further reduction of total steroid dose.

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.

Lack of metabolic effects of a triphasic formulation containing norethindrone in normal women studied prospectively

The glucose and insulin responses to oral glucose tolerance tests and lipid values in normal women taking a triphasic pill containing norethindrone (Ortho 7/7/7) were performed. After three months, no significant changes in these metabolic indices were found. These results confirm and expand the knowledge regarding the metabolic safety of norethindrone-containing triphasic formulations.

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.

Oral contraceptives in diabetic women: metabolic effects of four compounds with different estrogen/progestogen profiles

The metabolic effects of four oral contraceptives with different estrogen/progestogen profiles (monophasic nonalkylated estrogen/norethindrone, low-dose monophasic ethinyl estradiol (EE2)/norethindrone, progestogen only treatment with norethindrone, and triphasic EE2/levonorgestrel) were examined in insulin-dependent diabetic women. During the 6-month study period, no differences were found in fasting plasma glucose, 24-hour insulin requirements, glycated hemoglobin, free fatty acids, low-density lipoprotein cholesterol concentrations, or high-density lipoprotein cholesterol/total cholesterol ratio between the patients in each treatment group. Compared with the nonalkylated estrogen/norethindrone and the triphasic EE2/levonorgestrel formulations, the low-dose EE2/norethindrone combination resulted in small but significant increases in plasma triglyceride and very low-density lipoprotein cholesterol levels (P less than 0.01), which seemed unfavorable from a clinical point of view. Norethindrone-only treatment appeared to be an appropriate alternative to both the nonalkylated estrogen/norethindrone combination and the triphasic EE2/levonorgestrel formulations.

Oral contraceptives and insulin receptor binding in normal women and those with previous gestational diabetes

The effect of a low-dose triphasic oral contraceptive (ethinyl estradiol and levonorgestrel) on glucose tolerance, plasma insulin response to a glucose challenge, and insulin receptor binding to monocytes and erythrocytes was investigated in seven women with previous gestational diabetes and seven nondiabetic control subjects. Investigations were performed in the luteal phase before the hormonal intake and after hormonal treatment for 2 and 6 months. Before treatment, women with previous gestational diabetes had significantly impaired glucose tolerance (p less than 0.05) when compared with the healthy controls, but no differences in insulin receptor binding were observed. Glucose tolerance and the insulin response to oral glucose remained unchanged in both groups during the treatment period. In the control subjects a significant decrease (p less than 0.05) in insulin receptor binding to monocytes was observed after hormonal intake for 6 months whereas the insulin receptor binding remained unchanged in the women with previous gestational diabetes. No correlation was found between the receptor binding data obtained from monocytes and erythrocytes in either group of women. The study demonstrates that in lean nondiabetic women and women with previous gestational diabetes of normal weight without first-degree history of diabetes there is no apparent direct association between glucose tolerance, plasma insulin levels, and insulin binding to erythrocytes and monocytes during intake of low-dose oral contraceptives.