Abstract

Objective: To assess the relation of the metabolic insulin resistance syndrome (M-IRS) with coronary heart disease (CHD) in Pakistani patients.

Subjects: 200 patients with angiographic disease (CHD(+)) matched with 200 patients with chest pain without occlusive disease (CHD(−)).

Design: Prospective case–control study.

Setting: Tertiary referral cardiology unit in Pakistan.

Results: M-IRS was present in 37% of CHD(+) versus 27% of CHD(−) patients by criteria for white patients or 47% versus 42%, respectively, by Asian criteria (p < 0.001). After adjustment for other risk factors, M-IRS was not a significant predictor for CHD or angiographic disease. Age (p  =  0.03), smoking (p < 0.001), diabetes-years (p = 0.003), sialic acid (p  =  0.01), and creatinine (p  =  0.008) accounted for the excess risk of CHD. Similarly, age (p  =  0.005), creatinine (p < 0.001), cigarette pack-years (p  =  0.02), diabetes-years (p  =  0.003), and sialic acid (p  =  0.08) were predictors of greater angiographic disease. M-IRS differed between Pakistani and white patients, as waist circumference correlated weakly (r  =  −0.03–0.08, p  =  0.45–0.52) with triglycerides, high density lipoprotein cholesterol, systolic blood pressure, or glucose. Sialic acid was the only inflammatory marker associated with M-IRS.

Conclusions: Despite strong associations between individual risk factors associated with M-IRS and a univariate association between M-IRS and CHD in native Pakistanis, the principal discriminant risk factors in this group are age, smoking, inflammation, diabetes-years, and impaired renal function. The poor sensitivity of M-IRS for CHD reflects the high underlying prevalence of M-IRS, thus reducing sensitivity, confounding by other urban lifestyle traits, or a lack of association of waist circumference with M-IRS risk factors. The definition of M-IRS may have to be revised to increase its power as a discriminant risk factor for CHD in Pakistani populations.