At the time of the study, Dr. Waring was a scientist in the Epidemiology Research Center, Marshfield Clinic Research Foundation.
Evaluation of obesity as an independent risk factor for medically attended laboratory-confirmed influenza
Version of Record online: 14 MAY 2012
© 2012 Blackwell Publishing Ltd
Influenza and Other Respiratory Viruses
Volume 7, Issue 2, pages 160–167, March 2013
How to Cite
Coleman, L. A., Waring, S. C., Irving, S. A., Vandermause, M., Shay, D. K. and Belongia, E. A. (2013), Evaluation of obesity as an independent risk factor for medically attended laboratory-confirmed influenza. Influenza and Other Respiratory Viruses, 7: 160–167. doi: 10.1111/j.1750-2659.2012.00377.x
- Issue online: 11 FEB 2013
- Version of Record online: 14 MAY 2012
- Accepted 3 April 2012. Published Online 14 May 2012.
- Body mass index;
Please cite this paper as: Coleman et al. (2013) Evaluation of obesity as an independent risk factor for medically attended laboratory-confirmed influenza. Influenza and Other Respiratory Viruses 7(2) 160–167.
Background The relationship between obesity and susceptibility to influenza infection in humans is unclear. Morbidly obese people were at an increased risk of complications from 2009 pandemic H1N1 influenza [A(H1N1)pdm09].
Objective The goal of this study was to determine whether medically attended, laboratory-confirmed influenza is independently associated with obesity in adults with acute respiratory illness.
Patients/Methods Adults ≥20 years with a medical encounter for acute respiratory illness were recruited from a population cohort during the 2007–2008 (n = 903), 2008–2009 (n = 869), and 2009 pandemic (n = 851) season. Nasopharyngeal swabs were tested for influenza by real-time reverse-transcription polymerase chain reaction. Body mass index (BMI) was calculated using data from the electronic medical record. Logistic regression evaluated the association between influenza and obesity, adjusting for gender, vaccination, age, and high-risk medical condition.
Results Influenza was detected in 50% of patients in 2007–2008, 15% in 2008–2009, and 14% during the 2009 pandemic. Predominant seasonal viruses in this population were A/H3N2 in 2007–2008, and A/H1N1 and B in 2008–2009. Mean (±SD) BMI was 30·58 (±7·31) in patients with influenza and 30·93 (±7·55) in test-negative controls during all seasons. Mean BMI of patients with influenza did not vary by season. After adjusting for confounders, neither obesity nor extreme obesity were associated with influenza by season or for all years combined (OR 0·95: 95% CI 0·75, 1·20 and 1·10: 0·80, 1·52, respectively, for obesity and extreme obesity, all years).
Conclusions Obesity was not associated with medically attended influenza among adults with acute respiratory illness in this population.