Lovastatin enhances paraoxonase enzyme activity and quells low-density lipoprotein susceptibility to oxidation in type 2 diabetic nephropathy
Objectives: To investigate the effect of lovastatin therapy and withdrawal on paraoxonase 1 (PON1) and arylesterase (ARE) activities, and low-density lipoprotein cholesterol (LDL-C) susceptibility to oxidation in people with type 2 diabetic nephropathy (T2DN). Design and methods: Lovastatin (20 mg/day) was administered to 30 people with T2DN for 90 days and then withdrawn for 30 days. PON1 and ARE activities were measured by the spectrophotometric method. Susceptibility of LDL-C to oxidation was determined as the production of conjugated dienes. Results: After 90 days of lovastatin intervention, PON1 and ARE activities and LDL-C lag phase were significantly increased (p = 0.004, 0.002, and <0.001), while after 30 days of lovastatin withdrawal, PON1 and ARE activities and LDL-C lag phase had not changed significantly. Conclusion: Lovastatin therapy improves PON1 and ARE activities, and LDL-C susceptibility to oxidation. Despite withdrawal of lovastatin, PON1 and ARE activities, and LDL-C susceptibility to oxidation remain unchanged in people with T2DN. (C) 2010 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.