Key role of insulin resistance in vascular injury among hemodialysis patients

Abstract

Insulin resistance prevails not only among diabetic patients but also among hypertensive and obese patients. The relationship between insulin resistance and cardiovascular diseases was investigated in hemodialysis (HD) patients. Eighty-one maintenance HD patients were enrolled. The homeostasis model assessment of insulin resistance (HOMA-IR) method was used to assess insulin resistance. The relationship of HOMA-IR with cardiovascular and all-cause events was assessed. Compared with nondiabetic patients (n = 55), diabetic patients (n = 26) showed higher HOMA-IR (2.5 ± 0.3 vs 1.4 ± 0.2, P < .05), lower ankle-brachial pressure index (ABI, 0.85 ± 0.09 vs 1.12 ± 0.02, P < .01), and shorter HD duration (3 ± 1 vs 9 ± 1 years, P < .01), although their body mass index was similar (22.3 ± 0.5 vs 21.5 ± 0.4 kg/m 2). Nondiabetic patients taking angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (n = 36) had lower HOMA-IR (1.2 ± 0.2 vs 1.8 ± 0.4, P < .05) and higher ABI (1.18 ± 0.02 vs 1.02 ± 0.05, P < .01) than those without (n = 17). Cardiovascular events were less common in HD patients with normal HOMA-IR ( P < .05) or ABI ( P < .01). Our data indicate that 69% of diabetic and 27% of nondiabetic patients have HOMA-IR greater than 1.6, implying reduced insulin sensitivity in HD patients. The present results provide evidence that angiotensin inhibition improves insulin resistance, possibly preventing vascular injury in HD patients. Finally, our findings suggest that insulin resistance is prognostic of cardiovascular events in HD patients.