Insulin resistance and triglyceride/HDLc index are associated with coronary artery disease

Background: Insulin-resistance is associated with cardiovascular disease but it is not used as a marker for disease in clinical practice. Aims: To study the association between the homeostatic model assessment (HOMA-IR) and triglyceride/HDLc ratio (TG/HDLc) with the presence of coronary artery disease in patients submitted to cardiac catheterization. Methods: In a cross-sectional study, 131 patients (57.0 +/- 10 years-old, 51.5% men) underwent clinical, laboratory and angiographic evaluation and were classified as No CAD (absence of coronary artery disease) or CAD (stenosis of more than 30% in at least one major coronary artery). Results: Prevalence of coronary artery disease was 56.7%. HOMA-IR and TG/HDLc index were higher in the CAD vs No CAD group, respectively: HOMA-IR: 3.19 (1.70-5.62) vs. 2.33 (1.44-4.06), p = 0.015 and TG/HDLc: 3.20 (2.38-5.59) vs. 2.80 (1.98-4.59) p = 0.045) - median (p25-75). After a ROC curve analysis, cut-off values were selected based on the best positive predictive value for each variable: HOMA-IR = 6.0, TG/HDLc = 8.5 and [HOMA-IRxTG/HDLc] = 28. Positive predictive value for coronary artery disease for HOMA-IR>6.0 was 82.6%, for TG/HDLc>8.5 was 85.7% and for [HOMA-IRxTG/HDLc]>28 was 88.0%. Adjusted relative risk (age, gender, diabetes, body mass index, systolic blood pressure) for the presence of coronary artery disease was: for HOMA-IR>6.0, 1.47 (95.CI: 1.06-2.04, p = 0.027), for TG/HDLc>8.5, 1.46 (95% CI:1.07-1.98), p = 0.015) and for [HOMA-IR x TG/HDLc] >28, 1.64 (95%CI: 1.28-2.09), p < 0.001). Conclusions: Increased HOMA-IR, TG/HDLc and their product are positively associated with angiographic coronary artery disease, and may be useful for risk stratification as a high-specificity test for coronary artery disease.