Long-acting contraceptive raises glucose and insulin, but not much

A new study suggests that long-acting birth control with depot medroxyprogesterone acetate is associated with mild elevations of fasting glucose and insulin. Oral contraceptives are not.

The 3-year study by researchers at the University of Texas Medical Branch in Galveston measured fasting glucose and insulin levels at baseline and every 6 months thereafter in 703 Caucasian, African American, and Hispanic women who were using depot medroxyprogesterone acetate, oral contraceptive pills, or nonhormonal birth control.

Women using depot medroxyprogesterone acetate experienced slightly greater increases in glucose and insulin than women using nonhormonal birth control. Very-low-dose oral contraceptive users did not.

The authors write that increases are “probably not clinically meaningful,” and women taking “very-low-dose oral contraceptives with desogestrel will not experience any changes in fasting levels. Thus, data from this longitudinal study are reassuring overall regarding the effects of these 2 contraceptives on insulin-glucose metabolism.”

Serum glucose levels in women taking depot medroxyprogesterone acetate showed a small but steady increase during the first 30 months of use then leveled off. Serum insulin levels rose for the first 18 months of use before stabilizing.

Overweight or obese women using depot medroxyprogesterone acetate experienced slightly greater increases in insulin and glucose levels than normal-weight users.

The study was published in Obstetrics and Gynecology (2011;117[1]:41-47).