Atorvastatin increases HDL cholesterol in hypercholesterolemic patients. Evidence of a relationship with baseline HDL cholesterol

Abstract

Background and aim: It has been reported that atorvastatin increases high-density lipoprotein cholesterol (HDL-C) more in patients with low than in those with high baseline HDL-C levels. This may have a biological explanation, but also suggests a statistical artifact known as the regression to the mean.

Methods and results: Atorvastatin 10 mg/day led to a 4% increase in HDL-C after two months in 67/121 patients with hypercholesterolemia (55%), who had lower baseline HDL-C levels than the patients in whom HDL-C did not increase. In the patients with baseline HDL-C below the median, HDL-C significantly increased whereas no change was observed in patients with baseline HDL-C above the median. The correlation coefficient between pre- and post-treatment HDL-C was 0.84, thus suggesting a regression to the mean. However, the regression artifact did not entirely explain the increase in HDL-C in patients with low baseline HDL-C or the lack of an increase in those with high baseline HDL-C. The adjusted mean increase was 5.4% in patients with low pretreatment HDL-C, and 2.4% in the patients with high pretreatment HDL-C. Multiple regression analysis with the changes in HDL-C as the dependent variable showed that baseline HDL-C and the changes in serum triglycerides independently contributed to the change in HDL-C levels.

Conclusions: Atorvastatin 10 mg/day increases HDL-C more in patients with low pretreatment HDL-C levels, an effect that seems to be related to the hypotriglyceridemic activity of the drug.