Clinical Importance of Obesity Versus the Metabolic Syndrome in Cardiovascular Risk in Women

TLDR

Obesity and metabolic syndrome frequently coexist and both are linked to cardiovascular disease, yet the independent contribution of obesity to cardiovascular risk remains uncertain. In the WISE study, 780 women undergoing coronary angiography were categorized by BMI and metabolic syndrome status (with or without diabetes) to compare the prevalence of significant coronary artery disease and 3‑year cardiovascular risk across these groups. The metabolic syndrome, but not BMI, was associated with significant coronary artery disease and a two‑fold increase in 3‑year risk of death or major adverse cardiovascular events, indicating that metabolic syndrome—not obesity alone—predicts future cardiovascular risk in women.

Abstract

Background— Obesity and the metabolic syndrome frequently coexist. Both are associated with cardiovascular disease (CVD). However, the contribution of obesity to cardiovascular risk, independent of the presence of the metabolic syndrome, remains controversial. Methods and Results— From the WISE study, 780 women referred for coronary angiography to evaluate suspected myocardial ischemia were classified by body mass index (BMI; <24.9=normal, n=184; ≥25.0 to ≤29.9=overweight, n=269; ≥30.0=obese, n=327) and presence (n=451) or absence (n=329) of the metabolic syndrome, further classified by diabetes status. Prevalence of significant angiographic coronary artery disease (CAD; ≥50% stenosis) and 3-year risk of CVD were compared by BMI and metabolic status. The metabolic syndrome and BMI were strongly associated, but only metabolic syndrome was associated with significant CAD. Similarly, unit increases in BMI (normal to overweight to obese) were not associated with 3-year risk of death (adjusted hazard ratio [HR] 0.92, 95% CI 0.59 to 1.51) or major adverse cardiovascular event (MACE: death, nonfatal myocardial infarction, stroke, congestive heart failure; adjusted HR 0.95, 95% CI 0.71 to 1.27), whereas metabolic status (normal to metabolic syndrome to diabetes) conferred an approximate 2-fold adjusted risk of death (HR 2.01, 95% CI 1.26 to 3.20) and MACE (HR 1.88, 95% CI 1.38 to 2.57). Levels of C-reactive protein (hs-CRP) were more strongly associated with metabolic syndrome than BMI but were not independently associated with 3-year risk of death or MACE. Conclusions— The metabolic syndrome but not BMI predicts future cardiovascular risk in women. Although it remains prudent to recommend weight loss in overweight and obese women, control of all modifiable risk factors in both normal and overweight persons to prevent transition to the metabolic syndrome should be considered the ultimate goal.