Effect of injectable and oral contraceptives on glucose and insulin levels.

OBJECTIVE: To estimate the effect of using two methods of hormonal contraceptives (depot medroxyprogesterone acetate) or an oral contraceptive pill (OCP) containing 20 micrograms ethinyl estradiol and 0.15 mg desogestrel) on serum glucose and insulin levels, as well as predictors of any observed changes.
METHODS: Fasting glucose and insulin levels were measured on 703 white, African-American, and Hispanic women using depot medroxyprogesterone acetate, OCPs, or nonhormonal birth control at baseline and every 6 months thereafter for 3 years. Participants also completed questionnaires containing demographic and behavioral measures every 6 months. Mixed-model regression analyses were used to estimate changes over time in glucose and insulin levels by method, along with their predictors.
RESULTS: Depot medroxyprogesterone acetate, but not OCP, users experienced slightly greater increases in glucose and insulin as compared with nonhormonal users (P<.001). Among depot medroxyprogesterone acetate users, a small but steady increase in serum glucose levels (2 mg/dL at 6 months to 3 mg/dL at 30 months) was observed throughout the first 30 months, but it leveled off after that. In contrast, serum insulin levels showed an upward (3 units at 6 months to 4 units at 18 months) trend for the first 18 months of depot medroxyprogesterone acetate use and then remained almost flat thereafter. Elevation of insulin and glucose levels was slightly more pronounced in obese and overweight depot medroxyprogesterone acetate users than those who were normal weight.
CONCLUSION: Use of depot medroxyprogesterone acetate, but not very-low-dose OCPs containing desogestrel, can lead to slightly higher fasting glucose and insulin levels. LEVEL OF EVIDENCE: II.