• Wei Nie, Yi Zhang, Sun Ha Jee, Keum Ji Jung, Bing Li, and Qingyu Xiu.
• Department of Respiratory Medicine, Shanghai Changzheng Hospital, Second Military Medical University, 415 Fengyang Road, Shanghai 200003, China. lbxwzhao@gmail.com.
• Bmc Med. 2014 Apr 10; 12: 61.

BackgroundIt is unclear whether an 'obesity survival paradox' exists for pneumonia. Therefore, we conducted a meta-analysis to assess the associations between increased body mass index (BMI), pneumonia risk, and mortality risk.MethodsCohort studies were identified from the PubMed and Embase databases. Summary relative risks (RRs) with their corresponding 95% confidence intervals (CIs) were calculated using a random effects model.ResultsThirteen cohort studies on pneumonia risk (n = 1,536,623), and ten cohort studies on mortality (n = 1,375,482) were included. Overweight and obese individuals were significantly associated with an increased risk of pneumonia (RR = 1.33, 95% CI 1.04 to 1.71, P = 0.02, I(2) = 87%). In the dose-response analysis, the estimated summary RR of pneumonia per 5 kg/m(2) increase in BMI was 1.04 (95% CI 1.01 to 1.07, P = 0.01, I(2) = 84%). Inversely, overweight and obese subjects were significantly associated with reduced risk of pneumonia mortality (RR = 0.83, 95% CI 0.77 to 0.91, P < 0.01, I(2) = 34%). The estimated summary RR of mortality per 5 kg/m(2) increase in BMI was 0.95 (95% CI 0.93 to 0.98, P < 0.01, I(2) = 77%).ConclusionsThis meta-analysis suggests that an 'obesity survival paradox' exists for pneumonia. Because this meta-analysis is based on observational studies, more studies are required to confirm the results.

19 keywords...

hide…