Insulin resistance phenotypes and coronary artery disease in a native Pakistani cohort.

Objective: To determine the relationship between insulin resistance (IR) and atheroma burden in Pakistanis.

Methods: A prospective case-control study of 400 patients selected for the presence/absence of angiographic disease. Coronary atheroma burden was quantified and IR and cardiovascular risk factors were measured.

Results: The patients were divided into two groups by QuickI score. Waist circumference (90 +/- 10 vs. 90 +/- 9 cm; p = 0.7) was similar but the groups differed in body mass index (26.5 +/- 3.7 vs. 24.2 +/- 3.5 kg/m(2); p < 0.001) and waist:hip ratio (0.94 +/- 0.09 vs. 0.90 +/- 0.06; p < 0.001). Lipid parameters showed similar high-density lipoprotein cholesterol (HDL-C) (0.77 +/- 0.23 vs. 0.82 +/- 0.22 mmol/l; p = 0.1) differences in triglycerides [1.32 (0.08-3.98) vs. 1.12 (0.37-3.61) mmol/l; p = 0.01], but no difference in low-density lipoprotein cholesterol (LDL-C) (2.75 +/- 1.00 vs. 2.90 +/- 0.94 mmol/l; p = 0.14). In insulin-resistant patients C-reactive protein (CRP) [6.8 (0.3-175.1) vs. 3.9 (0.2-57.9) mg/l: p < 0.001], sialic acid (82 +/- 14 vs. 77 +/- 15 mg/l; p < 0.001) aspartate transaminase [24 (7-171) vs. 21 (7-83) IU/l; p < 0.001] and gamma-glutamyl transferase [27 (8-482) vs. 21 (7-168) IU/l; p = 0.005] levels were increased. In insulin-resistant patients (n = 187), coronary artery disease (CAD) burden correlated (r = 0.55) with age (beta = 1.62; p < 0.001), HDL-C (beta = -53.2; p < 0.001), lipoprotein (a) (beta = 11.4; p = 0.007), smoking (beta = 7.98; p = 0.004), CRP (beta = 6.06; p = 0.03) and QuickI index (beta = -146; p = 0.04). In contrast in insulin-sensitive patients (n = 178) CAD burden (r = 0.46) correlated with LDL-C (beta = 10.0; p = 0.02), CRP (beta = 7.13; p = 0.03), HDL-C (beta = -38.1; p = 0.03), and weakly with age (beta = 0.73; p = 0.07) and smoking (beta = 5.52; p = 0.09).

Conclusions: Indian Asians show a dichotomous insulin-resistance phenotype. Atheroma is associated with low HDL-C and inflammation associated in all but LDL-C is a factor in the insulin sensitive in contrast to age and extent of IR in the insulin resistant.