Waist circumference, metabolic syndrome and coronary artery disease in a Pakistani cohort.

Background: Metabolic syndrome (M-IRS) is common in Asians. This study investigated the relationship of two definitions of M-IRS to atherosclerosis in Indian Asians with suspected coronary arterial disease (CAD).

Methods: 400 patients with chest pain selected for the presence or absence of angiographic disease were recruited from a tertiary referral centre in Pakistan into a prospective case-control study. Patients were categorized by the National Cholesterol Education Program adult treatment panel 3 (NCEP) and International Diabetes Federation (IDF) definitions of the metabolic syndrome and the relationship of these to the presence of CAD and extent of atheroma burden was investigated.

Results: M-IRS was present in 53% by IDF criteria and in 44% using the Asian criteria for NCEP. The 2 populations identified were only 69% concordant. No relationship existed between the presence of NCEP M-IRS and atheroma burden. In contrast, the presence of IDF M-IRS was associated with CAD (65 vs. 34%; RR=1.88; p<0.001) and angiographic disease burden (28 [0-224] vs. 0 (0-198); RR=1.83; p<0.001). This association persisted (beta=18.4; p<0.001) after correction for C-reactive protein (beta=8.67; p<0.001), lipoprotein (a) (beta=8.14; p=0.002), and estimated glomerular filtration rate (beta=-0.22; p=0.01). Differences in presumed underlying factors were found in the 2 populations identified by the definitions though both agreed on the separate weightings given to blood pressure and HDL-C/apolipoprotein A1.

Conclusions: The specific Asian IDF and NCEP definitions of M-IRS show limited concordance in Pakistanis. The IDF criteria in contrast to the NCEP criteria are associated with the presence of CAD even after allowing for other risk factors identified in this population.