Obesity Has Paradoxical Effect on Heart Attack Outcomes
Low body mass index and high waist-to-hip ratio associated with increased mortality rates
THURSDAY, Oct. 16 (HealthDay News) -- In patients with ST-segment elevation acute myocardial infarction, the relationship between obesity and outcomes is complex and deserves further study, according to a report published in the Oct. 15 issue of the American Journal of Cardiology.
Sang-Hee Lee, M.D., of Yeungnam University Hospital in Pusan, South Korea, and colleagues categorized 3,734 patients into four groups for body mass index and into two sets of four groups for waist-to-hip ratio.
In the body mass index category, the researchers found that underweight patients were more likely than obese patients to be older and present with heart failure. In the waist-to-hip category, they found a reverse pattern. After a mean 199 days of follow-up, the investigators found that mortality was highest in patients with the lowest body mass index and the highest waist-to-hip ratio. In both categories, the authors report that important mortality risk factors were underweight (hazard ratio 2.88) and a high waist-to-hip ratio (HR, 5.57).
"Although it is beyond the scope of the assessments in the present study, visceral adipose tissue is a major site of cytokine production that contributes to atherosclerotic progression and plays a major role in insulin resistance and dyslipidemia and in the induction of prothrombotic and chronic inflammatory states," Lee and colleagues write. "We posit that these inherent differences between waist-to-hip ratio and body mass index may explain the persistent reverse trends between the two anthropometric categories seen for important clinical factors and outcomes."