Gestational diabetes mellitus (GDM) is one of the most common complications of pregnancy although it usually develops in fewer than 10% of all pregnancies. The condition, unique to pregnancy, threatens the health of the woman and the child she carries.

The condition usually resolves itself after childbirth but its effects linger forever. Women diagnosed with GDM are at great risk of developing type 2 diabetes mellitus (T2DM) in the years after pregnancy.

The findings of a recently published study suggest having the one form of diabetes won’t always lead to the other and there are some clearly defined steps a woman can take to dramatically reduce her risk of T2DM following GDM during pregnancy. The most effective way to reduce the risk of chronic diabetes is to simply keep moving.

The research team tapped into data from the Nurses’ Health Study II, which is part of a long-term, ongoing study called the Diabetes & Women’s Health Study. The research team, led by Wei Bao, MD, Ph.D., found 4,554 women in the nurses study who were at one time diagnosed with GDM. The research team tracked their health from 1991 to 2007.

At intervals throughout the study period — in 1991, 1997, 2001, and 2005 — each woman completed a questionnaire describing her state of health and physical activity level. Also documented were each woman’s television-watching habit and the extent of other sedentary behaviors.

Over the course of study, 635 women developed T2DM. The women diagnosed with type 2 diabetes watched more TV and got less physical exercise than the women who were not diagnosed with type 2:

    •    100 minutes per week of physical exercise at moderate activity reduced the risk of type 2 by 9%.
    •    Already-active women who increased their level of exercise to 150 minutes per week of moderate-intensity lowered their risk of type 2 almost in half (47%).
    •    These reduced risk levels for T2DM remained constant among the active group regardless of each woman’s individual body mass index (BMI).

For all women in the study, TV time was measured in increments of:

    •    Fewer than 5 hours per week
    •    6 to 10 hours
    •    11 to 20 hours
    •    20+ hours per week

The more time a woman spent sitting still watching TV the greater her risk of developing type 2 diabetes. Where sedentary activities were concerned, body mass did matter. The women with the higher BMIs (greater body weight) were more likely to develop type 2 diabetes than more slender women.

The Bao study provides clear evidence that a woman’s sedentary lifestyle choices can invite the development of T2DM while the choice to maintain a moderate level of activity can dramatically spare her development of this chronic, debilitating disease that is growing in epidemic proportion around the world.

Source: Bao, Wei, et al. “Physical Activity and Sedentary Behaviors Associated With Risk of Progression From Gestational Diabetes Mellitus to Type 2 Diabetes Mellitus: A Prospective Cohort Study.” JAMA Internal Medicine. American Medical Association. May 19, 2014. Web. Jun 16, 2014.