Understanding the potential role of statins in pneumonia and sepsis.

OBJECTIVE: To examine the association of statin use with clinical outcomes and circulating biomarkers in community-acquired pneumonia and sepsis. DESIGN: Multicenter inception cohort study. SETTING: Emergency departments of 28 U.S. hospitals. PATIENTS: A total of 1895 subjects hospitalized with community-acquired pneumonia. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Our approach consisted of two different comparison cohorts, each reflecting methods used in prior publications in this area. We first compared subjects with prior statin use (prior use cohort), defined as a history of statin use in the week before admission, with those with no prior use. We then compared prior statin users whose statins were continued inhospital (continued use cohort) with those with either no prior use or no inhospital use. We adjusted for patient characteristics, including demographics, comorbid conditions, and illness severity, and accounted for healthy user effect and indication bias using propensity analysis. We determined risk of severe sepsis and 90-day mortality. We measured markers inflammation (tumor necrosis factor, interleukin-6, interleukin-10), coagulation (antithrombin, factor IX, plasminogen activator inhibitor, d-dimer, thrombin antithrombin complex), and lymphocyte cell surface protein expression during the first week of hospitalization. There were no differences in severe sepsis risk between statin users and nonusers for prior (30.8% vs. 30.7%, p = .98) or continued statin use (30.2% vs. 30.8%, p = .85) in univariate analyses and after adjusting for patient characteristics and propensity for statin use. Ninety-day mortality was similar in prior statin users (9.2% vs. 12.0%, p = .11) and lower in continued statin users (7.9% vs. 12.1%, p = .02). After adjusting for patient characteristics and propensity for statin use, there was no mortality benefit for prior (odds ratio, 0.90 [0.63-1.29]; p = .57) or continued statin use (odds ratio, 0.73 [0.47-1.13]; p = .15). Only antithrombin activity over time was higher in statin subjects, yet the magnitude of the difference was modest. There were no differences in other coagulation, inflammatory, or lymphocyte cell surface markers. CONCLUSIONS: We found no evidence of a protective effect for statin use on clinical outcomes and only modest differences in circulating biomarkers in community-acquired pneumonia, perhaps as a result of healthy user effects and indication bias.

Differences in immune response may explain lower survival among older men with pneumonia.

OBJECTIVE: Lower life expectancy in men is generally attributed to higher likelihood of risky behavior and because men develop chronic conditions earlier. If sex-related differences in survival are independent of preinfection chronic health and health behavior, it would suggest that survival differences may occur because of sex differences in quality of care and biological response to infection, and these differences may contribute to sex differences in life expectancy. We assessed if sex-related survival difference following community-acquired pneumonia (CAP) is due to differences in clinical characteristics, quality of care, or immune response. DESIGN, SETTING, AND SUBJECTS: Prospective observational cohort of 2183 subjects with CAP. MEASUREMENTS AND MAIN RESULTS: Mean age was 64.9 years. Men were more likely to smoke and had more comorbidity compared with women. At emergency department presentation, men had different biomarker patterns, as evidenced by higher inflammation (tumor necrosis factor, interleukin [IL]-6, and IL-10) and fibrinolysis (d-dimer), and lower coagulation biomarkers (antithrombin-III and factor IX) (p < 0.05). Small differences in favor of men were seen in care quality, including antibiotic timing and compliance with American Thoracic Society guidelines. Men had lower survival at 30, 90, and 365 days. The higher 1-year mortality was not attenuated when adjusted for differences in demographics, smoking, resuscitation, insurance, and vaccination status, comorbidity, hospital characteristics, and illness severity (unadjusted hazard ratio [HR] = 1.35, p = 0.003; and adjusted HR = 1.29, p = 0.004). HR was no longer statistically significant when additionally adjusted for differences in emergency department concentrations of tumor necrosis factor, IL-6, IL-10, d-dimer, antithrombin-III, and factor IX (adjusted HR = 1.27, p = 0.17). Patterns of biomarkers observed in men were associated with worse survival for 1 year. CONCLUSIONS: Lower survival among men following CAP was not explained by differences in chronic diseases, health behaviors, and quality of care. Patterns of inflammatory, coagulation, and fibrinolysis biomarkers among men may explain reduced short-term and long-term survival.