Oral Contraceptive Use and Association With Glucose, Insulin, and Diabetes in Young Adult Women: The CARDIA Study

Catherine Kim, MD, MPH, David S. Siscovick, MD, MPH, Stephen Sidney, MD, MPH, Cora E. Lewis, MD, MSPH, Catarina I. Kiefe, MD, PHD, Thomas D. Koepsell, MD, MPH

Disclosures

Diabetes Care. 2002;25(6) 

In This Article

Abstract and Introduction

Objective. We studied the associations between 1) current use of oral contraceptives (OCs) and 2) glucose levels, insulin levels, and diabetes in young women.
Research Design and Methods. Subjects were women (n = 1,940) in the Coronary Artery Risk Development in Young Adults (CARDIA) study, a prospective observational study of African-Americans and whites aged 18–30 years at enrollment in 1985–1986. We analyzed the cross-sectional associations between 1) current use of OCs and 2) fasting glucose, fasting insulin, and presence of diabetes using generalized estimating equations to adjust for repeated measures. We also examined the effect of current use of OCs on incident diabetes at year 10 of the study.
Results. In unadjusted analyses, current use was associated with lower fasting glucose levels [–3.1 mg/dl, 95% CI (-3.7, -2.5)] and reduction in the odds of diabetes [odds ratio 0.56 (0.32, 0.97)], but not lower fasting insulin levels [-0.01 µU/ml (-0.03, 0.02)], compared with nonuse in both African-American and white women. After adjustment for covariates, current use of OCs was still associated with lower fasting glucose levels [–1.8 mg/dl (-2.4, –1.3)] and lower odds of diabetes [odds ratio 0.56 (0.33, 0.95)], although the associations were attenuated. After adjustment, current use of OCs was associated with higher insulin levels [0.12 µU/ml (0.006, 0.23)]. No association existed between pattern of use of OCs and incident diabetes at year 10, although the total number of new persons with diabetes at year 10 was small (n = 17).
Conclusions. Current use of OCs is associated with lower glucose levels in young African-American and white women and may be associated with lower odds of diabetes.

Given the increasing incidence of type 2 diabetes in the U.S. among young minority women [1,2], it is important to understand the association between combination oral contraceptives (OCs) and glucose intolerance in this population. Combination estrogen-progestin OCs are used by more than 10 million women in the U.S. [3], and most studies indicate that they are associated with increased glucose and insulin levels [4–7].

However, the association has been inconsistent. This inconsistency is possibly explained by small numbers of participants and inability to evaluate and adjust for all potential confounders, such as increased BMI, age, nonwhite race, lower education level, family history of diabetes, or health behaviors. Also, studies that did not find an association did not specifically exclude persons with diabetes, and persons with diabetes may have taken OCs less often because of their disease [8,9].

Prospective cohort studies of both older high-dose estrogen-progestin formulations [10] and newer low-dose estrogen-progestin formulations [11] did not find an increased incidence of type 2 diabetes in current OC users or former OC users after adjustment for these factors. However, the populations studied had an older age at enrollment and were not adjusted for race. They were also unable to study fasting glucose or insulin levels and, therefore, the effect of use of OCs on concurrent glucose and insulin metabolism.

To determine whether use of OCs increased glucose and insulin levels and risk of diabetes, we studied the cross-sectional association between 1) current use of OCs and 2) glucose levels, insulin levels, and diabetes in a population of 1,940 young African-American and white women participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study. We also examined the longitudinal association between current use of OCs and incident diabetes at year 10. Extensive data were collected on possible confounders.

Comments

3090D553-9492-4563-8681-AD288FA52ACE
Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as:

processing....