Abstract 19160: Insulin Resistance over a 10-Year Period is Associated with Coronary Atherosclerosis in HIV-Infected and Uninfected Men in the Multicenter AIDS Cohort Study

Abstract

Aims: HIV infection and its treatments are associated with insulin resistance and diabetes, which may influence the risk of coronary artery disease (CAD). We investigated the degree of insulin resistance in HIV-infected and uninfected men and its association with coronary atherosclerosis. Methods: We conducted a multicenter, cross-sectional study which included 448 HIV-infected and 306 uninfected men, ages 40 to 70 years old, without a history of prior coronary revascularization from the Multicenter AIDS Cohort Study (MACS). Coronary computed tomography angiography (CTA) was performed to identify the presence of coronary artery plaque, to characterize plaque composition (calcified, non-calcified, and mixed), and to identify coronary artery stenoses > 50%. Insulin resistance was evaluated by the homeostatic model assessment (HOMA-IR) measured at each semi-annual visit between 2003 and 2014. The mean HOMA-IR was calculated from all visits before participants underwent CTA. Associations between HOMA-IR and the prevalence of plaque or of stenosis > 50% were assessed with logistic regression by adjusting for age, race, HIV serostatus, and CAD risk factors. Results: Mean HOMA-IR compiled over a median of 8.4 years was higher in HIV-infected than uninfected men (3.2 vs. 2.7, p = 0.002), but the prevalence of stenosis > 50% was similar (17% vs. 15%, p = 0.41). In fully adjusted models comparing men in the highest and lowest tertiles of mean HOMA-IR, mean HOMA-IR was associated with the presence of stenosis > 50% (OR = 2.81 [95% CI, 1.51-5.22]), but not with any particular plaque type. There was no significant interaction between HIV serostatus and associations between mean HOMA-IR and coronary stenosis. Among HIV-infected men, further adjustment for HIV disease control and severity (suppressed HIV-1 RNA, CD4 T-cell count) did not alter the association between mean HOMA-IR and the presence of stenosis > 50% (OR = 2.67 [95% CI, 1.26-5.89]). Conclusions: Insulin resistance over a 10 year period was greater among HIV-infected than uninfected men and was associated with coronary artery stenosis, but not with any specific plaque type. Our findings suggest that insulin resistance is a potential mechanism mediating the increased risk of CAD among HIV-infected men.