Abstract 3144: Prevalence Of Insulin Resistance Among Non-diabetic Chronic Heart Failure Patients And Its Relation To Disease Severity

Abstract

Body: Background Purpose- There is increasing evidence of a reciprocal interrelationship between chronic heart failure (CHF) and insulin resistance (IR) such that IR may be pathophysiologically linked to the evolution of the disease in CHF. However, the prevalence of IR in the CHF population has not been fully defined. The purpose of this study was to establish the prevalence of IR among non-diabetic CHF patients and to assess its relation to disease severity. Methods- The homeostatic model of insulin resistance (HOMA-IR) was assessed in a cohort of 129 CHF patients; mean age (69.2±10.4 yrs) [range 30 –90 yrs], males 76%, CHF of ischemic etiology 82.2% and BMI (27.4±4.4kg/m2). All were on regular CHF medication. Patients underwent cardiopulmonary exercise testing and peripheral endothelial function testing by reactive hyperemia peripheral arterial tonometry (RH-PAT). Results- Prevalence of IR as defined by Fasting Insulin Resistance Index >2.7 was 61% in CHF and was significantly higher than in the 23 subjects who were coronary artery disease controls without HF(P<0.05). The degree of IR was not related to the etiology of CHF. There was a significant correlation between IR and serum triglyceride (r = 0.333, P<0.01), HDL cholesterol (r = − 0.275, p<0.05), impaired fasting glucose (r = 0.358, P<0.01) and central obesity (r = 0.232, p<0.01). The degree of IR was related to the exercise capacity and peak oxygen consumption (VO 2 ). Mean of IR increased significantly with worsening functional NYHA Classes I, II, III and IV [2.1, 2.9, 4.8, 8.9], (r = 0.437, p<0.01). The IR patients had a significantly lower exercise duration (340 ±168.3 vs. 601 ±265.9 s, p< 0.01) and peak VO 2 (6.4 ± 2.3 vs. 14.5 ±1.7 ml/kg per min, p< 0.05). Exercise peak cardiac output determined by the inert gas re-breathing method was lower in patients with IR (5.2 ±1.2 vs. 9.2 ± 0.89 l/min, p<0.05). Endothelial function as measured by RH-PAT decreased significantly in patients with IR compared to the patients with normal insulin sensitivity (1.64 ± 0.36 vs. 2.0 ± 0.53, p<0.05I). Conclusion - These findings suggest that IR is highly prevalent among CHF patients and is associated with decreased exercise effort and capacity in patients with CHF. Targeting IR might represent a new strategy in the treatment of CHF.