Overweight, obesity increased CVD risk, despite metabolic syndrome

Patients who are overweight or obese are at increased risk for developing MI or ischemic heart disease, regardless of whether they also have metabolic syndrome.

For a recent study, researchers categorized 71,527 white participants collected from the Copenhagen General Population Study according to BMI (normal, BMI 18.5 to 24.9, n=31,452; overweight, BMI 25 to 29.9, n=28,579; obese, BMI ≥30, n=11,496) and metabolic syndrome status. They evaluated the incidence of MI and ischemic heart disease during a median follow-up of 3.6 years.

Incident MI occurred in 634 cases, and 1,781 patients received a diagnosis of ischemic heart disease. Multivariate analysis indicated that overweight (HR=1.26; 95% CI, 1-1.61) and obese patients (HR=1.88; 95% CI, 1.34-2.63) without metabolic syndrome were at increased risk for MI compared with normal-weight patients without metabolic syndrome. Obese patients with metabolic syndrome were at further increased risk (HR=2.33; 95% CI, 1.81-3).

Similar but attenuated results were observed for the incidence of ischemic heart disease, with increased risk observed among obese patients both with (HR=1.67; 95% CI, 1.44-1.93) and without metabolic syndrome (HR=1.45; 95% CI, 1.2-1.77).

Multivariate analysis indicated that risk for MI was elevated across all BMI categories for patients with metabolic syndrome (adjusted HR=1.54; 95% CI, 1.32-1.81) vs. those without metabolic syndrome. However, cumulative incidence of MI (P=.006 for trend) and ischemic heart disease (P<.001) increased with increasing weight among patients with and without metabolic syndrome. No significant interaction was observed between increasing weight and the presence or absence of metabolic syndrome with regard to risk for MI (P=.9) or ischemic heart disease (P=.44).

“These findings suggest that overweight and obesity, even in the absence of metabolic syndrome, are not benign conditions, and that weight loss should be encouraged regardless of the presence or absence of metabolic syndrome to reduce risk of MI and ischemic heart disease,” the researchers concluded. “Our findings also suggest that metabolic syndrome is no more valuable than BMI in identifying individuals at risk of MI and ischemic heart disease.”

In a related commentary, Chandra L. Jackson, PhD, MS, and Meir J. Stampfer, MD, DrPH, of Harvard School of Public Health, said these results provide important new evidence about the adverse effects of being overweight, even among patients otherwise considered metabolically healthy.

“These results also underscore the importance of focusing on weight gain prevention due to the difficulty in achieving and maintaining weight loss to reverse being overweight or obese,” Jackson and Stampfer wrote.

For more information:

Jackson CL. JAMA Intern Med. 2013;doi:10.1001/jamainternmed.2013.8298.

Disclosure: The researchers, Jackson and Stampfer report no relevant financial disclosures.