This study examined the effects of simvastatin on C-reactive protein (CRP) and other inflammatory markers in study subjects with significant elevations in triglyceride (TG) blood levels. CRP, vascular cellular adhesion molecule (VCAM), serum amyloid A (SAA), and interleukin 6 (IL-6) were measured in archived plasma samples from 2 multicenter, randomized, double-blind, placebo-controlled studies designed to examine the lipid-altering efficacy of simvastatin in study subjects with elevated TGs. In the first study, 130 study subjects with mixed hyperlipidemia (low-density lipoprotein [LDL] cholesterol > or =130 mg/dl; TGs 300 to 700 mg/dl) received placebo or simvastatin 40 or 80 mg once daily for three 6-week periods in a complete-block crossover design. In the second study, 195 study subjects with hypertriglyceridemia (TGs 300 to 900 mg/dl) received daily doses of placebo or simvastatin 20, 40, or 80 mg for 6 weeks. Significant but weak correlations were observed between baseline CRP values and baseline levels of LDL cholesterol and high-density lipoprotein (HDL) cholesterol, but not with TGs. CRP was also correlated with body mass index and fasting levels of glucose and insulin. Treatment with simvastatin 20, 40, and 80 mg led to significant reductions in CRP plasma levels versus placebo (p <0.05). Although CRP change was weakly correlated with changes in LDL cholesterol, TGs, and HDL cholesterol, results of regression analyses showed that only baseline CRP and treatment allocation were significant predictors of CRP response after 6 weeks of study drug administration. Simvastatin had no effect on VCAM, SAA, or IL-6. In summary, simvastatin significantly reduced CRP in patients with mixed hyperlipidemia and hypertriglyceridemia.