The effect of simvastatin on inflammatory cytokines in community-acquired pneumonia: a randomised, double-blind, placebo-controlled trial

Abstract

Objectives: it has been suggested that statins have an effect on the modulation of the cytokine cascade and on the outcome of patients with community-acquired pneumonia (CAP). The aim of this prospective, randomised, double-blind, placebo-controlled trial was to determine whether statin therapy given to hospitalised patients with CAP improves clinical outcomes and reduces the concentration of inflammatory cytokines. Setting: a tertiary teaching hospital in Barcelona. Participants: thirty-four patients were randomly assigned and included in an intention-to-treat analysis (19 to the simvastatin group and 15 to the placebo group). Intervention: patients were randomly assigned to receive 20 mg of simvastatin or placebo administered in the first 24 h of hospital admission and once daily thereafter for 4 days. Outcome: primary end point was the time from hospital admission to clinical stability. The secondary end points were serum concentrations of inflammatory cytokines and partial pressure of arterial oxygen/fractional inspired oxygen (PaO2/FiO2) at 48 h after treatment administration. Results: the trial was stopped because enrolment was much slower than originally anticipated. The baseline characteristics of the patients and cytokine concentrations at the time of enrolment were similar in the two groups. No significant differences in the time from hospital admission to clinical stability were found between study groups (median 3 days, IQR 2-5 vs 3 days, IQR 2-5; p=0.47). No significant differences in PaO2/FiO2 (p=0.37), C reactive protein (p=0.23), tumour necrosis factor-α (p=0.58), interleukin 6 (IL-6; p=0.64), and IL-10 (p=0.61) levels at 48 h of hospitalisation were found between simvastatin and placebo groups. Similarly, transaminase and total creatine kinase levels were similar between study groups at 48 h of hospitalisation (p=0.19, 0.08 and 0.53, respectively). Conclusions: our results suggest that the use of simvastatin, 20 mg once daily for 4 days, since hospital admission did not reduce the time to clinical stability and the levels of inflammatory cytokines in hospitalised patients with CAP.