Open AccessBody mass index and the incidence of influenza‐associated pneumonia in a UK primary care cohort
Author(s) -
Blumentals William A.,
Nevitt Alan,
Peng Michael M.,
Toovey Stephen
Publication year - 2012
Publication title -
influenza and other respiratory viruses
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.743
H-Index - 57
eISSN - 1750-2659
pISSN - 1750-2640
DOI - 10.1111/j.1750-2659.2011.00262.x
Subject(s) - medicine , underweight , body mass index , overweight , pneumonia , incidence (geometry) , cohort , cohort study , obesity , retrospective cohort study , pediatrics , physics , optics
Please cite this paper as: Blumentals WA. et al. (2012) Body mass index and the incidence of influenza‐associated pneumonia in a UK primary care cohort. Influenza and Other Respiratory Viruses 6(1), 28–36. Background Accumulating data suggest an association between increased BMI/obesity and morbidity in patients with pandemic (H1N1) 2009 influenza. Information on metabolic status and prognosis in seasonal influenza is lacking, however. Methods A retrospective cohort study was carried out using the UK General Practice Research Database. Patients aged ≥18 with ≥1 recorded BMI in the 12–58 kg/m 2 range between January 1, 2000, and December 31, 2007, were observed for an influenza‐associated pneumonia diagnosis after the date of baseline BMI, including ‘influenza with pneumonia’ or a diagnosis of ‘pneumonia’ up to 30 days after a diagnosis of ‘influenza’. Results A total of 1 074 315 patients were included, of whom 73·2% were within the reference BMI range or overweight and 2·2% were underweight (<18·5 kg/m 2 ). Pneumonia rates were 32·33–37·48/100 000 in all BMI categories except the underweight (98·29/100 000). Relative to patients with acceptable weight, those who were underweight had an increased pneumonia rate [adjusted IRR = 2·32 (95% CI 1·80–2·94)], while being overweight (BMI = 25·0–29·9 kg/m 2 ) or obese (BMI ≥ 30·0 kg/m 2 ) was associated with a decreased pneumonia rate [adjusted IRR = 0·77 (95% CI 0·68–0·86) and 0·85 (95% CI 0·73–1·00), respectively]. On the other hand, women and obese women with type 2 diabetes had increased pneumonia rates [adjusted IRR = 1·37 (95% CI 1·08–1·72) and 1·47 (95%CI 1·01–2·06), respectively]. Conclusions In contrast to initial data from pandemic influenza, influenza pneumonia, and pneumonia following influenza were the most common in underweight persons, and an apparent decreased rate of pneumonia was noted with increasing BMI categories. Women with type 2 diabetes had increased rates of pneumonia.