Epidemiology

Altering metabolic syndrome criteria may be clinically useful

Last Updated: 2005-08-29 14:30:14 -0400 (Reuters Health)

NEW YORK (Reuters Health) - Using alternative metabolic syndrome criteria yields cardiovascular risk estimates comparable to those derived by using the National Cholesterol Education Program Adult Treatment Panel 3 (NCEP) criteria, according to results of a study published in the September issue of the American Journal of Epidemiology. However, evaluating risk on more of a continuum may allow consideration of alternative definitions by gender or for patients with other risk factors.

"Studies have shown an increased risk of cardiovascular outcomes with the metabolic syndrome, but information on predictive properties of the NCEP criteria is sparse," Dr. Cynthia J. Girman, of Merck Research Laboratories, West Point, Pennsylvania, and colleagues write.

Using data from the Hoorn population-based study in the Netherlands, the researchers examined the effect of varying cutpoints for the NCEP metabolic syndrome components and their association with cardiovascular morbidity and mortality. They used classification tree, survival tree, and hierarchical and nonparametric clustering techniques. In addition, the team assessed alternative approaches that may better characterize risk as a continuum.

Included in the study were 2484 subjects between the ages of 50 and 75 years. The participants were examined in 1989 and followed for cardiovascular morbidity and mortality through 2000 to assess NCEP criteria. Cluster analyses were used to assess whether NCEP identifies a mixture of heterogeneous groups.

Participants of each gender who met NCEP criteria appeared to be divided into clusters distinguished mainly by triglycerides or high-density lipoprotein cholesterol. When individual metabolic syndrome components were used separately, cutpoints of those predicting cardiovascular events using regression tree techniques varied by gender and endpoint. However, Cox model hazards were generally comparable to the NCEP criteria regardless of cutpoints (range 1.3 to 2.5).

Increasing numbers of components were associated with a clear gradation in risk of cardiovascular outcomes. This elevation in risk differed by gender, with statistically elevated risk for three or more NCEP components in men and for two or more components in women.

"Hence, using the number of components to reflect a gradation in risk may be more useful for clinicians in evaluating patients and considering therapeutic alternatives and lifestyle changes, as previously suggested, and may allow different criteria to be applied for women or patients with other risk factors, if warranted," Dr. Girman's team concludes.

Am J Epidemiol 2005;162:438-447.