Serum ubiquinone concentrations after short- and long-term treatment with HMG-CoA reductase inhibitors.

Serum ubiquinone levels were studied during long- and short-term treatment with 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase inhibitors in 17 men with primary non-familial hypercholesterolaemia. The serum ubiquinone levels were determined after the patients had received simvastatin (20-40 mg per day) for 4.7 years, after a 4 week treatment pause and again after they had resumed treatment with lovastatin (20-40 mg per day) for 12 weeks. During the treatment pause the average serum ubiquinone levels increased by 32%; resumption of treatment caused a reduction of 25%. The changes in the levels of ubiquinone and serum total cholesterol as well as those of ubiquinone and low-density lipoprotein cholesterol were closely parallel. This suggested that changes in serum ubiquinone reflected changes in cholesterol-containing serum lipoproteins which could serve as carrier vehicles for ubiquinone. After long-term simvastatin treatment and after short-term lovastatin treatment, average serum ubiquinone levels (1.16 and 1.22 mg.l-1, respectively) were similar to that observed in a group of apparently healthy middle-aged men (1.16 mg.l-1).