Objective: High-density lipoprotein (HDL)-associated paraoxonase (PON) activity may play an important role in the inhibition of low-density lipoprotein (LDL) oxidation. Previous studies have demonstrated that serum PON activity is decreased in patients with hyperlipoproteinaemia and coronary heart disease. The study presented here examined the effect of short-term treatment with simvastatin and atorvastatin on lipids and PON activity in patients with hyperlipoproteinaemia.
Research design and methods: A prospective, non-blinded, single-group, cross-over, comparative trial was performed. Following an 8-week dietary run-in period, 49 patients (23 men and 26 women, mean age: 59.8 +/- 7.9 years) with Fredrickson type IIa. and IIb. hyperlipoproteinaemias were randomized to receive either simvastatin 20 mg/day or atorvastatin 10 mg/day for 3 months. Following an 8-week washout period, patients were crossed-over to receive the other drug for a further 3 months. Serum lipids were measured and serum PON activity was determined spectrophotometrically using paraoxon as a substrate.
Results: Simvastatin treatment significantly reduced serum cholesterol, LDL-cholesterol (LDL-C) and apolipoprotein (apo) B levels (p < 0.001). Atorvastatin had a more pronounced cholesterol, LDL-C- and apo B-lowering effect (p < 0.001) compared with simvastatin. Both statins also significantly reduced serum triglyceride levels (p < 0.01). Simvastatin and atorvastatin caused no significant change in the levels of HDL-cholesterol (HDL-C) and apo A1. HDL-associated PON activity did not change significantly after simvastatin therapy, but significantly increased after atorvastatin treatment (p < 0.05).
Conclusions: Short-term administration of simvastatin did not increase PON activity. Atorvastatin treatment had a favourable effect on lipid profile and increased the activity of HDL-associated PON.