Engaging in regular vigorous physical activity before pregnancy reduces the risk of gestational diabetes mellitus (GDM).
Boston-based researchers led by Dr. Cuilin Zhang from the Harvard School of Public Health looked at the amount, type, and intensity of pre-gravid physical activity in relation to GDM risk in the Nurses’ Health Study II. Among 19,462 women who delivered at least one infant between 1990 and 1998, a new diagnosis of GDM was reported in 1192 women.
In analyses adjusted for a number of covariates including age, family history of diabetes and dietary factors, both total and vigorous activity were "significantly inversely related with GDM risk," the authors report in meeting materials.
For increasing quintiles of total activity, relative risks for GDM were 1.00, 1.02, 0.75, 0.90, and 0.73 (p for trend < 0.001). Adjustment for pre-pregnancy BMI attenuated ties between total activity and GDM risk, but the relationship between vigorous physical activity and reduced GDM risk remained significant. Women in the highest versus the lowest quintile of vigorous activity had a relative risk of 0.81 for GDM.
"Compared with women who were sedentary both at an early age and before the index pregnancy, those who frequently engaged in vigorous activity in both periods had a 26% lower risk of GDM," Dr. Zhang and colleagues report. Among women who did not participate in vigorous physical activity, faster walking pace and greater stair climbing also curbed the risk of GDM.
Compared with "casual" walking pace, adjusted relative risks for "normal" and "brisk" walking were 0.84 and 0.70, respectively. Compared with women who climbed 0 to 2 flights of stairs per day, women who climbed 15 or more flights of stairs per day had an adjusted relative risk of 0.42 for the development of GDM.
"Our prospective study suggests that regular physical activity is associated with lower GDM risk," the authors conclude.
Presented at the American Diabetes Association’s 65th Annual Scientific Sessions in San Diego.