The Effect of HMG-CoA Reductase Inhibitor on Insulin Resistance in Patients Undergoing Peritoneal Dialysis

Abstract

BACKGROUND: Insulin resistance is associated with the progression of atherosclerosis and is reported to predict cardiovascular mortality in patients with end-stage renal disease (ESRD). Although statins exert pleiotropic effects, it is uncertain whether statin therapy improves insulin resistance in these patients. In this prospective randomized controlled trial, we aimed to evaluate the effects of statin on insulin resistance among 70 patients undergoing peritoneal dialysis (PD). METHODS: Patients were randomized into a statin group (n = 35) or a control group (n = 35). The statin group received 10 mg per day of rosuvastatin for 6 months. We determined insulin resistance by homeostatic model assessment of insulin resistance (HOMA-IR) index. Serum concentrations of adipokines such as adiponectin, leptin, and resistin were measured using enzyme-linked immunosorbent (ELISA) assay. As inflammatory markers, high sensitive C-reactive protein (hsCRP) and interleukin-6 were also measured. RESULTS: There were no significant differences in baseline characteristics between the two groups. Compared to baseline value, statin treatment significantly decreased HOMA-IR index from 2.37 ± 1.08 to 2.05 ± 0.82 (P = 0.014). There was a concordant decrease in hsCRP levels in the statin group (2.05 ± 1.57 to 1.21 ± 0.84 mg/L, P < 0.001), but such improvements were not observed in the control group. When between-group differences in these parameters were compared, hsCRP levels were more decreased in the statin group than in the control group (P = 0.021 for between-group difference), whereas HOMA-IR index was not (P = 0.189 for between-group difference). During this period, statin treatment did not result in the improved adipokine profiles. CONCLUSION: This study showed that statin therapy failed to improve insulin resistance in PD patients despite a significant decline in hsCRP levels after statin treatment. Our finding suggests that reducing inflammation by statin is of limited help to fully attenuate insulin resistance in these patients.