Statins and the Risk of Pneumonia
Statins and the Risk of Pneumonia
Study Objective: To determine if the use of statins affects pneumonia-related outpatient visits, hospitalizations with survival, and deaths.
Design: Population-based, retrospective, nested case-control analysis.
Data Source: United Kingdombased General Practice Research Database.
Participants: The study population (134,262 patients aged 8E 30 yrs) consisted of 55,118 patients who took statins and/or fibrates, 29,144 patients with hyperlipidemia not taking lipid-lowering agents, and 50,000 randomly selected patients without hyperlipidemia and without lipid-lowering treatment.
Measurements and Main Results: We identified 1253 patients with pneumonia and matched them with 4838 control subjects based on age, sex, general practice, and index date. After adjusting for comorbidity and frequency of visits to general practitioners, we calculated the risks (odds ratios with 95% confidence intervals) of uncomplicated pneumonia, hospitalization for pneumonia with survival, and fatal pneumonia in participants who used statins compared with those who did not. Current statin users had a significantly reduced risk of fatal pneumonia (adjusted odds ratio 0.47, 95% confidence interval 0.250.88) and slightly but not significantly reduced risks of uncomplicated pneumonia and pneumonia hospitalization with survival. Recent or past statin use and fibrate use at any time were not associated with a reduced risk of pneumonia.
Conclusion: Current use of statins was associated with a reduced risk of pneumonia. The risk reduction was particularly strong in the subgroup of patients with fatal pneumonias.
The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) have antiinflammatory and immunomodulatory activities in addition to their lipid-lowering properties. In vitro¯ and in vivo studies¯ have shown that statins decrease levels of proinflammatory cytokines (e.g., tumor necrosis factor-a, interleukin [IL]-2, IL-6, interferon-g) and increase levels of antiinflammatory cytokines (e.g., IL-4, IL-5, IL-10). These effects are thought to contribute to the protection against cardiovascular and cerebrovascular diseases that statin treatment affords.
In addition, statins have beneficial effects on the clinical course of several infectious diseases, including bacterial sepsis in animals and humans.¯ Moreover, a recent retrospective cohort study showed that statin use was associated with a decreased risk of mortality in patients hospitalized with community-acquired pneumonia.
Hospital-based studies are not useful for evaluating the effects of statins on uncomplicated pneumonia requiring only outpatient treatment, severe pneumonia requiring hospitalization after which patients survive, or fatal pneumonia. For this reason, we undertook an observational study using a population-based database to determine whether treatment with statins affects these pneumonias in adults.
Abstract and Introduction
Abstract
Study Objective: To determine if the use of statins affects pneumonia-related outpatient visits, hospitalizations with survival, and deaths.
Design: Population-based, retrospective, nested case-control analysis.
Data Source: United Kingdombased General Practice Research Database.
Participants: The study population (134,262 patients aged 8E 30 yrs) consisted of 55,118 patients who took statins and/or fibrates, 29,144 patients with hyperlipidemia not taking lipid-lowering agents, and 50,000 randomly selected patients without hyperlipidemia and without lipid-lowering treatment.
Measurements and Main Results: We identified 1253 patients with pneumonia and matched them with 4838 control subjects based on age, sex, general practice, and index date. After adjusting for comorbidity and frequency of visits to general practitioners, we calculated the risks (odds ratios with 95% confidence intervals) of uncomplicated pneumonia, hospitalization for pneumonia with survival, and fatal pneumonia in participants who used statins compared with those who did not. Current statin users had a significantly reduced risk of fatal pneumonia (adjusted odds ratio 0.47, 95% confidence interval 0.250.88) and slightly but not significantly reduced risks of uncomplicated pneumonia and pneumonia hospitalization with survival. Recent or past statin use and fibrate use at any time were not associated with a reduced risk of pneumonia.
Conclusion: Current use of statins was associated with a reduced risk of pneumonia. The risk reduction was particularly strong in the subgroup of patients with fatal pneumonias.
Introduction
The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) have antiinflammatory and immunomodulatory activities in addition to their lipid-lowering properties. In vitro¯ and in vivo studies¯ have shown that statins decrease levels of proinflammatory cytokines (e.g., tumor necrosis factor-a, interleukin [IL]-2, IL-6, interferon-g) and increase levels of antiinflammatory cytokines (e.g., IL-4, IL-5, IL-10). These effects are thought to contribute to the protection against cardiovascular and cerebrovascular diseases that statin treatment affords.
In addition, statins have beneficial effects on the clinical course of several infectious diseases, including bacterial sepsis in animals and humans.¯ Moreover, a recent retrospective cohort study showed that statin use was associated with a decreased risk of mortality in patients hospitalized with community-acquired pneumonia.
Hospital-based studies are not useful for evaluating the effects of statins on uncomplicated pneumonia requiring only outpatient treatment, severe pneumonia requiring hospitalization after which patients survive, or fatal pneumonia. For this reason, we undertook an observational study using a population-based database to determine whether treatment with statins affects these pneumonias in adults.
