Does CVD Risk Remain Elevated in Metabolically Healthy Obesity?

Obesity is a risk factor for cardiovascular disease (CVD) even in women who are metabolically healthy for long periods of time, according to new findings.

Researchers arrived at this conclusion following a study of 121,701 female nurses enrolled in the Nurses’ Health Study. Of these participants, 103,298 answered a questionnaire in 1980, which was used as baseline in the present study.
_____________________________________________________________________________________

RELATED CONTENT
AHA Recommends Two Seafood Meals a Week to Lower CVD Risk
Which Obesity Treatment Is Best?
_____________________________________________________________________________________

Ultimately, following exclusion of those with a history of CVD or cancer, those with missing body weight measurements, and those with underweight, 90,257 women were followed from 1980 to 2010 for incident CVD. Median follow-up lasted 24 years.

Participants were categorized based on body mass index (BMI), metabolic health—defined as the absence of diabetes, hypertension, and hypercholesterolemia—and change in metabolic health status over the course of follow-up.

A total of 6306 cases of CVD, including 3304 cases of myocardial infarction (MI) and 3080 strokes, occurred over 2,127,391 person-years of follow-up. Results indicated that CVD risk was significantly elevated in women with metabolically unhealthy normal weight (hazard ratio [HR] 2.43], overweight (HR 2.61), and obesity (3.15).

CVD risk was also found to be higher in women with metabolically health obesity (HR 1.39), although to a lesser extent.

Ultimately, the researchers found that most metabolically healthy women in the study later converted to unhealthy phenotypes (2555 of 3027 with obesity, 22,215 women with normal weight after 20 years).

Women who maintained metabolically healthy obesity throughout follow-up still had a higher risk for CVD compared with women with stable, healthy normal weight (HR 1.57). However, this risk was lower than for initially metabolically healthy women who later converted to an unhealthy phenotype (HR: 1.90 [normal weight]; 2.74 [obesity]).

The presence of incident diabetes and hypertension was found to raise CVD risk among women who were initially metabolically healthy.

“Even when metabolic health is maintained during long periods of time, obesity remains a risk factor for cardiovascular disease,” the researchers concluded. “However, risks are highest for metabolically unhealthy women across all BMI categories.”

—Christina Vogt

Reference:

Eckel N, Li Y, Kuxhaus O, Stefan N, Hu FB, Schulze MB. Transition from metabolic healthy to unhealthy phenotypes and association with cardiovascular disease risk across BMI categories in 90 257 women (the Nurses' Health Study): 30 year follow-up from a prospective cohort study [Published online May 30, 2018]. Lancet Diabetes Endocrinol. https://doi.org/10.1016/S2213-8587(18)30137-2