Abstract P229: Pericardial Fat Density is Associated With Insulin Resistance in Treated HIV Infection: The SATURN-HIV Trial

Abstract

Objective: To examine associations of pericardial fat (PCF) volume and density with baseline and changes in insulin resistance among HIV+ subjects participating in a trial of statin therapy. Methods: SATURN-HIV was a 96-week double-blind, randomized trial of 10 mg daily rosuvastatin versus placebo among 147 HIV+ subjects on stable antiretroviral therapy with LDL-c ≤130mg/dL and evidence of heightened T-cell activation or increased inflammation (high sensitivity C-reactive protein ≥2mg/L). PCF volume (ml) and density (mean Hounsfield Units) were measured from coronary calcium CT scans at entry. Homeostatic model of insulin resistance (HOMA-IR) was calculated from insulin and glucose at entry, 24, 48, and 96 weeks. Pearson correlations and linear mixed modeling were used to explore relationships between PCF and insulin resistance. Results: Median (Q1, Q3) age was 46 (40, 53) years; 78% were male and 68% African American; 49% were on a protease inhibitor. Median HOMA-IR was 1.84 (1.06, 3.33) at baseline, and participants randomized to statin had larger 0-96 week mean percentage increase in HOMA-IR (+73% vs +33%, statin vs placebo, p=0.009). PCF density did not correlate with measures of total body adiposity (BMI r=0.057 and total body fat r=-0.034, both p>0.4), but was negatively correlated to waist-hip ratio (-0.337, p<0.001). In a linear mixed model, PCF density was associated with baseline HOMA-IR independent of PCF volume, BMI, metabolic syndrome, and biomarkers of immune activation and systemic inflammation; however, PCF density was not associated with longitudinal changes in HOMA-IR (see Table). Conclusions: Coronary calcium scans are widely used to assess cardiovascular risk and appropriateness of statin therapy. In this HIV+ population, PCF density, a simple measure obtained from these scans, appears to be a novel marker of insulin resistance that is independent of PCF volume. Larger, adequately powered studies are needed to determine if PCF density predicts development of insulin resistance on statin.