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

Association between contraceptive use and gestational diabetes: Missouri Pregnancy Risk Assessment Monitoring System, 2007-2008

Introduction

The efficacy and safety of contraceptives have been questioned for decades; however, whether a relationship exists between hormonal contraceptives and gestational diabetes (GDM) is undetermined. The aim of this study was to investigate whether maternal risk for GDM was influenced by type of contraceptive method used before pregnancy.

Methods

Data collected in 2007 and 2008 by the Missouri Pregnancy Risk Assessment Monitoring System (PRAMS) were analyzed to determine if type of contraception before pregnancy influenced maternal risk for GDM. We used a logistic regression model to determine the adjusted odds for GDM given exposure to hormonal forms of contraception.

Results

Of the 2,741 women who completed the 2007–2008 PRAMS survey, 8.3% were diagnosed with gestational diabetes, and 17.9% of the respondents had used hormonal contraceptive methods. Women who used hormonal methods of birth control had higher odds for gestational diabetes (adjusted odds ratio [AOR] = 1.43; 95% confidence interval [CI], 1.32–1.55) than did women who used no contraception. A protective effect was also observed for women who had used barrier methods of contraception (AOR = 0.79; 95% CI, 0.72–0.86).

Conclusion

Findings suggest there may be a relationship between type of contraceptive method and GDM. More research is needed to verify contraception as a potential risk factor for GDM.

Effect of low-dose oral contraceptives on metabolic risk factors in African-American women

CONTEXT

The effect of oral contraceptive pill (OCP) use on cardiovascular risk in African-American women is unknown.

OBJECTIVE

Our objective was to examine in African-American women the effect of OCP use on insulin resistance, glucose intolerance, and triglycerides (TGs).

DESIGN

This was a cross-sectional study.

SETTING

The study was conducted at the National Institutes of Health Clinical Research Center.

PARTICIPANTS

A total of 104 healthy nondiabetic African-American women [21 OCP users, 83 controls, age mean +/- sd, 34.7 +/- 7.6 yr, body mass index (BMI) 31 +/- 8.4 kg/m(2)] was included in the study.

INTERVENTIONS

Subjects had oral glucose tolerance tests, insulin-modified frequently sampled iv glucose tolerance tests, and fasting lipid profiles. Insulin resistance was determined by the insulin sensitivity index (S(I)).

MAIN OUTCOME MEASURES

Insulin resistance, glucose tolerance status, and TG levels were determined.

RESULTS

Fasting glucose did not differ between OCP users and controls (P = 0.27). In contrast, compared with controls, 2-h glucose (135 +/- 23 vs.120 +/- 25 mg/dl; P = 0.01) and fasting TGs (73 +/- 31 vs.57 +/- 27 mg/dl; P = 0.02) were higher in OCP users. OCP users tended to be more insulin resistant than controls (S(I): 2.51 +/- 2.01 vs. 3.46 +/- 2.09; P = 0.09). Multiple regression analysis revealed that BMI, age, and OCP use were significant determinants of 2-h glucose (adjusted R(2) = 0.37; P < 0.001) and TG levels (adjusted R(2) = 0.21; P < 0.001). As BMI was a determinant of both 2-h glucose and TGs, participants were divided into nonobese and obese groups, and the analyses repeated. Among the nonobese women, the OCP users were more insulin resistant (S(I): 2.91 +/- 1.58 vs. 4.35 +/- 1.88; P = 0.03) and had a higher prevalence of glucose intolerance than controls (odds ratio 5.7; 95% confidence interval 1.4-24; P = 0.01).

CONCLUSION

In African-American women, OCP use is associated with an increase in markers of cardiovascular risk manifested by increased insulin resistance, glucose intolerance, and elevated TGs.

A 1-year randomized study to evaluate the effects of a dose reduction in oral contraceptives on lipids and carbohydrate metabolism: 20 microg ethinyl estradiol combined with 100 microg levonorgestrel

OBJECTIVES

To evaluate the impact on lipid and carbohydrate variables of a combined one-third ethinyl estradiol (EE)/levonorgestrel (LNG) dose reduction in oral contraceptives.

METHODS

In an open-label, randomized study, a dose-reduced oral contraceptive containing 20 microg EE and 100 microg LNG (20 EE/100 LNG) was compared with a reference preparation containing 30 microg EE and 150 microg LNG (30 EE/150 LNG). One-year data from 48 volunteers were obtained.

RESULTS

We found a decrease of HDL2 cholesterol and increases of low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol and total triglycerides in both treatment groups from baseline to the 13th treatment cycle. Although for four of six variables, the changes in the 20 EE group were lower compared with the 30 EE group, none of the differences between the two treatments were statistically significant. The median values for the fasting levels of insulin, C-peptide and free fatty acids slightly increased or remained unchanged while the fasting glucose levels slightly decreased after 13 treatment cycles. While the glucose area under the curve (AUC) (0-3 h) was similar in both groups during the OGTT, the insulin AUC(0-3 h) was less increased in the 20 EE/100 LNG group compared with the 30 EE/150 LNG group. None of the differences between the treatment groups for any of the carbohydrate metabolism variables were statistically significant at any time point. Both study treatments were safe and well tolerated by the volunteers.

CONCLUSION

Similar effects on the lipid and carbohydrate profiles were found for both preparations. The balanced one-third EE dose reduction in this new oral contraceptive caused slightly lower, but insignificant, changes in the lipid and carbohydrate variables compared with the reference treatment.

A randomized study over 13 cycles to assess the influence of oral contraceptives containing ethinylestradiol combined with drospirenone or desogestrel on carbohydrate metabolism

In this open-label, randomized study we compared the influence of a new oral contraceptive containing 30 microg ethinylestradiol and 3 mg drospirenone (Yasmin) with a reference preparation containing 30 microg ethinylestradiol and 150 microg desogestrel (Marvelon) on variables of carbohydrate metabolism by means of oral glucose tolerance tests at baseline and in the 6th and 13th treatment cycle. The mean levels of fasting glucose and insulin were similar at baseline and after 13 treatment cycles, whereas C-peptide and free fatty acid levels decreased slightly in both groups. All blood glucose and insulin values measured in the oral glucose tolerance tests were within normal ranges, despite a slight increase in the mean areas under the curves of 0-3 h [AUCs (0-3 h)] of both variables from baseline to treatment cycle 13. Differences between both treatments were not statistically significant. The mean AUCs (0-3 h) for C-peptide were not markedly changed in any treatment group. Free fatty acid levels decreased by 42% in the drospirenone group and increased by 48.9% in the desogestrel group, in terms of means of individual changes. Both preparations were well tolerated and equally efficacious regarding contraception and cycle control. The mean body weight was slightly decreased in most cycles during treatment with the drospirenone combination, as compared to baseline, while it was slightly increased versus baseline in all cycles during treatment with the desogestrel combination. The combination with drospirenone had less impact on blood pressure than the combination with desogestrel. In conclusion, Yasmin, a combined low-dose oral contraceptive with 30 microg ethinylestradiol and 3 mg of the novel progestogen drospirenone, as well as the reference Marvelon, containing 30 microg ethinylestradiol and 150 microg desogestrel had little impact on carbohydrate metabolism when used for 1 year. The observed changes were small and not suggestive of a clinically relevant deterioration of carbohydrate metabolism.

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.

Oral contraceptive use and glucose metabolism in a national sample of women in the united states

OBJECTIVE

This study was undertaken to determine whether users of oral contraceptives in a nationally representative population of US women had elevated levels of measures of glucose metabolism.

STUDY DESIGN

Cross-sectional data from the Third National Health and Nutrition Examination Survey (1988-1994) included hemoglobin A(1c) levels and fasting glucose, insulin, and C-peptide levels. Means were compared among those who had never used oral contraceptives, current users of oral contraceptives, and former users of oral contraceptives, with and without adjustment for potential confounders.

RESULTS

The vast majority of current users of oral contraceptives were using low-dose estrogen formulations. The two most common preparations were a triphasic formulation containing 0. 035 mg ethinyl estradiol and 0.5, 0.75, and 1 mg norethindrone (23. 9%) and a monophasic formulation containing 0.035 ethinyl estradiol and 1 mg norethindrone (20.7%). Current users of oral contraceptives did not have elevated values for any of the four measures of glucose metabolism. Hemoglobin A(1c) level and fasting glucose, insulin, and C-peptide levels were not related to duration of current use, age at which use began, or major formulation type. Among women who were former users of oral contraceptives there was no evidence of higher values among those who had recently ceased use.

CONCLUSION

Oral contraceptive formulations currently available in the United States are not associated with an adverse glucose metabolic profile.

Diabetes mellitus and fertility control: contraception management issues

The need to prevent complications in the woman and fetus mandates that pregnancies in diabetic women always be planned and that safe and effective contraceptives be used at all times until it is determined that pregnancy is a safe and desired option. Pregnancy may aggravate complications of diabetes such as retinopathy and coronary artery disease. A pregnant diabetic woman is also more likely to experience such complications as hypertension, urinary tract infection, polyhydramnios, and cesarean section. Her fetus is at increased risk for congenital malformations, prematurity, stillbirth, neonatal morbidity, and diabetes later in life. Good diabetic control must be maintained before and throughout the pregnancy to minimize the risk of these and other complications. Until such time as good control is achieved and the woman desires pregnancy, a reliable method of contraception should be used. Most recent research supports the use of barrier methods, low-dose monophasic or triphasic oral contraceptives, or progestin-only methods, at least for the short-term. Under some circumstances the intrauterine device may be an appropriate option. Long-term data regarding the use of these methods is lacking. The decision regarding which method of contraception is used should be made by the woman in consultation with her physician.

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

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

Glucose tolerance in women: the effects of age, body composition, and sex hormones

OBJECTIVE

To determine the separate and interactive effects of age, phase of the menstrual cycle, menopausal hormone status, body fat mass, and regional fat distribution on glucose tolerance in healthy women.

DESIGN

Retrospective study.

SETTING

The Baltimore Longitudinal Study of Aging.

PATIENTS

Two hundred sixty healthy women aged 22-89 years.

MEASUREMENTS

Plasma levels of estradiol and progesterone, body mass index (BMI), waist-to-hip ratio (WHR), and plasma glucose values in the fasting state (FPG) as well as 120 minutes after 40 gm/m2 of oral glucose (G120) were measured for each participant.

RESULTS

We found a progressive decline in oral glucose tolerance of 0.4 mM (6.7 mg/dL)/decade at G120) in women from early to late adult years, with no relationship to phase of the menstrual cycle and no abrupt change associated with the menopause. Multiple regression analysis revealed significant, independent effects of BMI and WHR on FPG and G120. The influence of age (P less than 0.01) on G120 was stronger than that of the BMI or WHR (P less than 0.05). There was no significant relationship between the levels of endogenous sex hormones and glucose tolerance after adjustments for age, BMI, and WHR. However, women taking oral contraceptives, but not those receiving postmenopausal replacement therapy, did exhibit mildly elevated G120 values.

CONCLUSIONS

Age per se, and to a lesser extent BMI and WHR, but not levels of endogenous sex steroids, contribute to the physiological decline in glucose tolerance in older women.

Epidemiologic studies utilizing surveys: accounting for the sampling design

BACKGROUND

Since large-scale health surveys usually have complicated sampling schemes, there is often a question as to whether the sampling design must be considered in the analysis of the data. A recent disagreement concerning the analysis of a body iron stores-cancer association found in the first National Health and Nutrition Examination Survey and its follow-up is used to highlight the issues.

METHODS

We explain and illustrate the importance of two aspects of the sampling design: clustering and weighting of observations. The body iron stores-cancer data are reanalyzed by utilizing or ignoring various aspects of the sampling design. Simple formulas are given to describe how using the sampling design of a survey in the analysis will affect the conclusions of that analysis.

RESULTS

The different analyses of the body iron stores-cancer data lead to very different conclusions. Application of the simple formulas suggests that utilization of the sample clustering in the analysis is appropriate, but that a standard utilization of the sample weights leads to an uninformative analysis. The recommended analysis incorporates the sampling weights in a nonstandard way and the sample clustering in the standard way.

CONCLUSIONS

Which particular aspects of the sampling design to use in the analysis of complex survey data and how to use them depend on certain features of the design. We give some guidelines for when to use the sample clustering and sample weights in the analysis.

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.