In metabolically healthy obesity, risk remains for CVD in women
Women with metabolically healthy obesity are at increased long-term risk for cardiovascular disease vs. metabolically healthy normal-weight women, suggesting that obesity is an independent risk factor, according to an analysis of the Nurses’ Health Study published in The Lancet Diabetes & Endocrinology.
“Obesity remains a risk factor for CVD, even if obese women maintain to be free of metabolic disease, such as diabetes, hypertension or hypercholesterolemia, during long periods of time,” Nathalie Eckel, MSc, a pharmacist and epidemiologist with the German Institute of Human Nutrition in Nuthetal, Germany, told Endocrine Today. “However, the onset of these metabolic diseases increases the risk for CVD not only among obese, but also among many overweight and normal-weight women.”
Eckel and colleagues analyzed data from 90,257 women free of cancer or CVD at baseline participating in the 1980 wave of the Nurses’ Health Study, which includes a biennial questionnaire on lifestyle, health behavior and medical history mailed to participants every 2 years. Researchers followed the cohort through 2010 for incident CVD (fatal and nonfatal myocardial infarction, stroke and total CVD), cross-classifying participants by BMI category, metabolic health (defined as the absence of diabetes, hypertension and hypercholesterolemia) and change in metabolic health status over follow-up. Researchers used Cox proportional hazard models with age as the underlying time scale to calculate risk for total CVD, MI and stroke among women stratified by BMI and metabolic health status.
During 2,127,391 person-years of follow-up with a mean follow-up of 24 years, researchers observed 6,306 cases of CVD, including 3,304 incidents of MI and 3,080 strokes. The researchers found that CVD risk was high among all metabolically unhealthy women; however, women with metabolically healthy overweight (HR = 1.2; 95% CI, 1.04-1.39) and obesity (HR = 1.39; 95% CI, 1.15-1.68) had increased risk for CVD vs. women with metabolically healthy normal weight.
Researchers also found that women who were metabolically healthy at baseline but developed metabolic derangements over time had a CVD risk similar to women who were metabolically unhealthy at baseline. Women with normal weight (HR = 1.29; 95% CI, 1.05-1.58), overweight (HR = 1.93; 95% CI, 1.64-2.26) and obesity (HR = 2.17; 95% CI, 1.83-2.58) who developed incident diabetes saw increasing risk for CVD vs. metabolically healthy normal-weight women without diabetes. Women who were metabolically healthy at baseline who developed incident hypertension had about double the risk for CVD vs. metabolically healthy normal-weight women without incident hypertension, whereas initially metabolically healthy women who developed hypercholesterolemia saw a slightly higher risk for CVD vs. women with metabolically healthy normal weight without incident hypercholesterolemia.
“Still, women with metabolically healthy obesity remained at an increased risk compared with those with metabolically healthy normal weight, even if they did not develop the individual risk factors,” the researchers wrote.
The researchers further investigated the effect of changes in metabolic health status during follow-up, noting that among women who were metabolically healthy in 1980, most converted to metabolically unhealthy over time in all BMI categories. Among women with metabolically healthy obesity at baseline, only 6.1% were still metabolically healthy in 2010, they wrote.
“Obese women should reduce weight regardless of their metabolic health status,” Eckel told Endocrine Today. “Prevention of weight gain remains a main target. However, maintenance of metabolic health is also important for overweight and even normal-weight healthy women.” – by Regina Schaffer
For more information:
Nathalie Eckel, MSc, can be reached at the Department of Molecular Epidemiology, German Institute of Human Nutrition, Potsdam-Rehbrücke, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany; email: firstname.lastname@example.org.
Disclosure: Eckel reports no relevant financial disclosures.