Birth Control Pills’ Diabetes Risk, Safety For Sickle Cell Patients Unclear

Hormonal contraceptives are unlikely to predispose women to type 2 diabetes and appear to be safe for those with sickle cell anemia. However, the evidence in both cases is incomplete, according to two new research reviews.

The effect of contraceptives on blood glucose and insulin levels among women without diabetes appears limited in the 24 studies analyzed by Laureen Lopez, Ph.D., of Family Health International and colleagues.Their review appears in The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.Most of the studies included in the Cochrane review were small and prone to patients dropping out, and half of the studies had weight restrictions for the women who participated. “Therefore, we still know very little about women at risk for metabolic problems due to being overweight,” Lopez said.The majority of the research compared different kinds of birth control pills consisting of a mix of the hormones progestin and estrogen used for three months to two years. Women who took a pill with desogestrel as the progestin had better blood glucose levels than those who took other kinds of pills, but the effect was inconsistent when it came to insulin levels, the authors found.Hormonal contraceptives with desogestrel, often called “third-generation” birth control pills, include the brands Ortho-Cept, Cyclessa and Mircette.The jury is still out on whether women with sickle cell disease, a hereditary condition that affects red blood cells, should use hormonal contraceptives, according to a second review by Anu Manchikanti and colleagues at Family Health International.The authors were only able to find one controlled safety study among women with sickle cell disease, a trial with 25 women who had three monthly injections of a progestin-only contraceptive commonly called Depo.Women who received the injections were less likely to have episodes of severe pain called sickling crises than those who got saline injections, the study concluded. “Depo appears to be a safe birth control option and may reduce the frequency of bone pain,” Manchikanti said.Elyse Mandell, A.P.R.N., a nurse practitioner in the hematology division of Brigham and Women’s Hospital in Boston, said there is nothing particular about sickle cell disease that would preclude using hormonal birth control.”I don’t think any of the methods of birth control confer any increased risk to women with sickle cell disease. So whatever will be used, faithfully and correctly, is OK with us,” she said of the hematology groups’ recommendations.(Source: The Cochrane Library : Brigham and Women’s Hospital : June 2007.)