The effect of statins on insulin resistance is controversial and poorly studied in nondiabetic subjects. In addition, the effect of statins on leptin and adiponectin has never been studied.
Forty healthy nondiabetic volunteers (22 men and 18 women) aged 28 to 72 were randomized either to placebo or pravastatin 40 mg daily for a 12-week period. Insulin resistance, assessed using the Quantitative Insulin Sensitivity Check Index (QUICKI), as well as serum leptin and adiponectin levels, was measured at baseline and at the end of therapy.
Pravastatin treatment decreased total cholesterol, low-density lipoprotein cholesterol, and triglycerides levels by 24%, 32%, and 14%, respectively (P < .05 for all), but did not affect glucose and insulin levels, the (QUICKI) index, and adiponectin and leptin levels. When stratification was performed according to QUICKI index or sex, no significant differences were observed in the prevalues and postvalues of leptin, adiponectin, or QUICKI index in the pravastatin group. Adiponectin, leptin, and QUICKI index were statistically higher in women than in men (P < .001 for both variables). Adiponectin was negatively correlated with body mass index (BMI; r = -0.39, P < .05) and positively correlated with the QUICKI index (r = 0.54, P < .001) and with high-density lipoprotein cholesterol (r = 0.50, P < .01). The relation between adiponectin and QUICKI index remained significant after adjustment for sex and BMI (P = .005 and P = .007, respectively). Leptin was only related to BMI (r = 0.57, P < .001) and to sex (P < .001) with no significant correlations with lipid parameters or QUICKI index. Both sex and BMI are independent predictors of leptin (P < .001 and P < .001).
A 12-week treatment with pravastatin 40 mg/d does not change the QUICKI index and leptin and adiponectin levels in healthy volunteers. In addition, our results emphasize the importance of sex and BMI in the determination of both adiponectin and leptin. Adiponectin was also related to QUICKI index, whereas this relation was not found with leptin.