More time sitting down may increase risk for heart disease and diabetes in older women. Photo by anaterate
Feb. 17 (UPI) -- There's an old saying about "idle hands," but it's idle bodies that women should be worried about as they age, according to a study published Monday in the Journal of the American Heart Association.
Researchers assessed the sitting habits of older, post-menopausal women and found those who spent more time seated, and were either overweight or obese, had a higher risk of heart disease and diabetes.
"The findings of this study build upon earlier research including our own, which showed, among older women, that too much time in sedentary behaviors was associated with higher risk for diabetes and heart disease," Dorothy D. Sears, professor of nutrition at the Arizona State University College of Health Solutions and a co-author on the study, said in a press release.
For the study, Sears and her colleagues enrolled 518 Hispanic and non-Hispanic women, who, on average, were 63 years of age and had a body mass index of 31 kg/m2. A BMI greater than 30 is considered the minimum threshold for obesity.
Study participants wore accelerometers on their right hip for up to 14 days, tracking and recording sitting and physical activity, removing them only to sleep, shower or swim. A blood test, performed concurrently with accelerometer wear, measured blood sugar and insulin resistance.
Data from study participants was analyzed as a single group and by two ethnic groups -- Hispanic women and non-Hispanic women -- in order to determine if total sitting time or average uninterrupted sitting periods had an impact on heart disease risk factors and whether these relationships varied by ethnicity.
The authors found post-menopausal Hispanic women sat, on average, almost one hour less per day than non-Hispanic women of the same age group, and they also spent significantly less time in periods of uninterrupted sitting. Overall, post-menopausal Hispanic women sat an average of about 8.5 hours per day, compared to more than 9 hours per day among non-Hispanic women.
Each additional hour of sitting time per day was linked with a more than 6 percent higher fasting insulin and a more than 7 percent increase in insulin resistance, while each additional 15 minutes in average sitting period was associated with a greater than 7 percent higher fasting insulin and an almost 9 percent increase in insulin resistance.
Notably, each additional 15-minute increase in uninterrupted sitting was associated with an approximately 5 percent higher fasting blood sugar in Hispanic women, compared to a less than 1 percent increase in non-Hispanic women.
Insulin resistance is a strong risk factor for both cardiovascular disease and type 2 diabetes, the authors noted.
"We were surprised to observe such a strong negative link between the amount of time spent sitting and insulin resistance, and that this association was still strong after we accounted for exercise and obesity," Sears said, adding that reducing sitting time improves glucose control and blood flow, and engaging in physical activities -- even light-intensity daily life activities like cooking and shopping -- can help prevent, or at least reduce risk for, heart disease and stroke.
"Health care providers should encourage patients, including older adults, to reduce their sitting time, take breaks in their sitting time and replace sitting with brief periods of standing or light physical activity," Sears said.