We’ve heard a lot about the health benefits of exercise. But what about the effects of prolonged sitting that comes with increasing screen time and many desk jobs?
It seems that for some post-menopausal women, sitting more during the day—or doing so for longer stretches at a time—is associated with being at greater risk for heart disease, according to research
published in the Journal of the American Heart Association
. This trend was true for both Hispanic and non-Hispanic women. But while women of Hispanic descent spent less of their day sitting and sat for shorter times, they had higher bumps in fasting blood sugar with each additional 15-minutes of uninterrupted sitting sit (5% versus 1% seen in the non-Hispanic group).
Researchers looked at the sitting habits of 518 women with an average age of 63 who were also overweight or obese. Of those, 102 women were Hispanic. Study participants wore activity monitors on their hips for 14 days except when sleeping, bathing or swimming. These devices tracked and recorded sitting and physical activity. Sitting behavior was measured by total sitting time each day, as well as the average time of uninterrupted sessions, or bouts, of sitting throughout the day. A single blood test was done during this time to measure blood sugar levels and insulin resistance, which is a strong risk factor for heart disease and type 2 diabetes.
Overall, post-menopausal Hispanic women sat for an average of 8½ hours per day, compared with more than 9 hours per day among non-Hispanic women. Researchers found that sitting for longer was associated with a higher risk for heart disease and diabetes, given higher levels of body mass index (BMI), waist circumference, fasting blood sugar, insulin, and triglycerides—a type of fat in the blood. Each additional hour of sitting time each day was associated with higher BMI, waist circumference, insulin, and insulin resistance. Insulin resistance occurs when the body produces insulin but fails to use it correctly, leading to high blood sugar levels.
The possible heart risks of sitting for too long was worse among women who were obese compared with overweight women. In addition, the connection between sitting time and heart disease risk remained even after accounting for women’s exercise levels, meaning that the potential heart harms of sitting were seen even among women who exercised regularly.
Researchers note that this is an important study given that Americans over 60 are more prone to sitting and other sedentary behaviors. Also, women’s chance of developing heart disease goes up as levels of the hormone estrogen decline after menopause.
“Traditionally, clinicians focus on encouraging patients to exercise more and increase physical activity with little focus specifically on sitting time,” the authors wrote. Their findings underscore the need to advise older adults on strategies for how to cut down on sitting time and add brief periods of activity and exercise when sitting for long stretches.
This is an observational study, which means additional research is needed to determine whether sitting habits are, in fact, resulting in worse heart disease risk factors. But this research demonstrates a clear link, especially as the relationship between sitting for longer remained even after accounting for age, education, marital status, weight, and physical fitness.