Bottom Line: Increased physical activity among women who had gestational diabetes mellitus (GDM) can lower the risk of progression to Type 2 diabetes mellitus (T2DM).1
Author: Wei Bao, M.D., Ph.D., of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Rockville, Md., and colleagues.
Background: GDM is a common pregnancy complication, defined as glucose intolerance with onset or first recognition during pregnancy. T2DM is an escalating worldwide epidemic and preventing the disease is a global health priority. About one-third of women of reproductive age with T2DM have a history of GDM, so a diagnosis of GDM may provide an opportunity for women to recognize the increased risk of T2DM and take steps to try to prevent it in the future.
How the Study Was Conducted: The authors examined the role of physical activity, television watching and other sedentary activity, along with changes in these behaviors, in the progression to T2DM. The study included 4,554 women from the Nurses’ Health Study II who had a history of GDM and were followed from 1991 to 2007.
Results: The authors documented 635 cases of T2DM. Each increase in an increment of 5-metabolic equivalent hours per week (MET-h/wk), which is equal to about 100 minutes per week of moderate-intensity physical activity or 50 minutes per week of vigorous-intensity activity, was associated with a 9 percent lower risk of T2DM. Women who increased their total physical activity levels by the federal government recommendation of 7.5 MET-h/wk or more (equivalent to 150 minutes per week of moderate-intensity physical activity or 75 minutes per week of vigorous-intensity activity) had a 47 percent lower risk of T2DM. While an increase in physical activity was associated with a lower risk for T2DM, an increase in the amount of time spent watching TV was associated with a greater risk of T2DM.
Discussion: “These findings suggest a hopeful message to women with a history of GDM, although they are at exceptionally high risk for T2DM, promoting an active lifestyle may lower the risk.”
In a related commentary2, Monique Hedderson, Ph.D., and Assiamira Ferrara, M.D., Ph.D, of Kaiser Permanente Northern California, Oakland, write: “The study by Bao et al in this issue sends a hopeful message to women with GDM, suggesting that it is possible to reduce diabetes risk through modifiable lifestyle behavior. Considering the urgency of addressing the current diabetes and obesity epidemics, their article is also a call to action for researchers and health systems to develop successful interventions to increase physical activity among women of reproductive age.”
1. JAMA Intern Med. Published online May 19, 2014. doi:10.1001/jamainternmed.2014.1795.
2. JAMA Intern Med. Published online May 19, 2014. doi:10.1001/jamainternmed.2014.709.