Abdominal obesity is an independent predictor of heart failure hospitalization and recurrent cardiovascular events in patients with stable coronary heart disease (CHD), according to the prospective cohort Heart and Soul Study published Oct. 1 in the American Journal of Cardiology.
Christian Spies, MD, from the Queen's Medical Center in Honolulu, Hawaii, and colleagues said the goal of their present study was to identify potential mechanisms underlying the association between obesity and recurrent events among patients with established CHD.
The researchers measured the waist-to-hip ratio and body mass index in 979 outpatients with stable CHD and followed them for a mean of 4.9 years. They used proportional hazards models to evaluate the extent to which the association of obesity with subsequent heart failure hospitalization or cardiovascular events (MI, stroke or CHD death) was explained by baseline co-morbidities, cardiac disease severity, inflammation, insulin resistance, neurohormones and adipokines.
Of the 979 participants, the investigators reported that 13 percent were hospitalized for heart failure and 16 percent developed a cardiovascular event. Each standard deviation increase in the waist-to-hip ratio was associated with a 30 percent increased risk of heart failure hospitalization.
The authors noted that this association was not attenuated after adjustment for potential mediators. Likewise, they said each standard deviation increase in the waist-to-hip ratio was associated with a 20 percent greater risk of cardiovascular events and this remained unchanged after adjustment for potential mediators.
However, the body mass index was not associated with the risk of heart failure or cardiovascular events.
Spies and colleagues observed discordance in the associations of the waist-to-hip ratio and body mass index with the left ventricular mass index—a “discrepancy not been previously reported and [one that] warrants additional study.”
They also noted that the association between abdominal obesity to heart failure hospitalization and recurrent cardiovascular events does not appear to be mediated by co-morbid conditions, cardiac disease severity, insulin resistance, inflammation, neurohormones or adipokines.
The researchers said that the “main strength” of the study was the collection of detailed phenotypic data, including “measurement of an extensive list of possible mediators of the association between abdominal obesity and adverse cardiovascular events.”