Exercise May Be Best Heart Protection for Overweight Women

Physical activity among overweight women lowered likelihood of being at risk for heart disease

(RxWiki News) Exercise is key to losing weight and keeping that weight off, which is healthy for the heart. But even without weight loss, physical activity may provide quite a bit of benefit to the heart.

A new study showed that for otherwise healthy middle-aged women who were overweight or obese, physical activity was the only lifestyle factor that protected against becoming at-risk for heart disease.

"Get active to lose weight."

This study was led by Unab Khan, MBBS, MS, assistant professor of pediatrics and of family and social medicine at Albert Einstein College of Medicine.

According to Khan and colleagues, being overweight or obese raises a person’s risk for developing heart disease-related conditions, such as hypertension (high blood pressure), which is among the leading causes of death in the US.

For this seven-year study, the researchers identified 866 women, ranging in age from 42 to 52 years, who were enrolled in the Study of Women’s Health across the Nation (SWAN), a mixed ethnicity study designed to examine the health of women during their middle years.

At the start of this study, the women were labeled as metabolically benign overweight/obese women, which means they had at most one risk factor for heart disease, and therefore were at a lower risk for developing heart disease later in life.

Women with a body mass index (BMI) of 25-29.99 were considered overweight. Those with a BMI of 30 or more were considered obese. BMI is a ratio of weight to height that is used to determine if someone is overweight, underweight or a healthy weight.

The researcher's main goal was to identify risk factors that push these women into the at-risk category of overweight/obese. In other words, they were looking for factors that might put women at risk for developing conditions like heart disease. These researchers were also trying to pinpoint possible factors that could prevent women from ever reaching the high-risk classification.

Over the course of the study, the women were tested yearly for heart disease risk factors. They were asked to complete a yearly survey describing the amount and type of physical activity they did in the prior year. Answers ranged from an active lifestyle playing sports and exercising to caregiving and doing housework.

Of the 866 study participants, 373 (43 percent) had progressed from having at most one risk factor for heart disease to having two or more of the following heart disease risk factors: hypertension, low blood level of HDL ("good") cholesterol, elevated blood levels of triglycerides (a fat found in blood), elevated fasting glucose levels (indicating possible pre-diabetes or diabetes) and elevated levels of C-reactive protein (a test which reveals levels of inflammation).

Being physically active at the start of and during the study was the only lifestyle factor found to protect overweight and obese women from becoming high-risk for heart disease. More specifically, women who were more physically active were 16 percent less likely to become at-risk for developing a heart condition.

However, the researchers did note some medical triggers that predisposed women to becoming at-risk for heart disease, even if they were physically active. Women with high levels of glucose (blood sugar) or who were already on a diabetes treatment (such as insulin) and women with hypertension at the beginning of the study were three times more likely to have heart disease.

Study participants who gained weight during the study were also 16 percent more likely to become at-risk for heart disease compared to women who did not gain weight.

“A large number of women who began the study — more than 40 percent of them — were no longer heart-healthy by the end of it," Dr. Khan said in a press statement. "But our study does demonstrate the important role that physical activity can play in protecting overweight or obese women from becoming at-risk for heart disease.”

Overall, the study’s findings suggested that physical activity may help prevent overweight women from developing chronic heart diseases, even if they have previously been diagnosed with risk factors for the disease.

This study was published May 20 in the Journal of Clinical Endocrinology & Metabolism.

SWAN had grant support from the National Institutes of Health, the National Institute on Aging, the National Institute of Nursing Research and the Office of Research on Women’s Health. No conflicts of interest were reported.

Review Date: 
May 26, 2014