Effect of Low-Dose Oral Contraceptives on Metabolic Risk Factors in African-American Women

Abstract

Abstract 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/m2] 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 (SI). 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 (SI: 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 R2 = 0.37; P < 0.001) and TG levels (adjusted R2 = 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 (SI: 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.