Is weight associated with severity of acute respiratory illness?

Obesity was an independent risk factor for severe disease in hospitalized adults during the 2009 pandemic H1N1 influenza season. Few studies have investigated the association between weight and severity of acute respiratory illnesses in children or in adults seeking care in the emergency department (ED) during other winter respiratory seasons.

We prospectively and systematically enrolled patients ≥2 years of age who presented to the ED or inpatient setting in a single geographic region with fever/acute respiratory illness over four consecutive winter respiratory seasons (2010-2014). We collected demography, height and weight, and high risk co-morbid conditions. Multivariable logistic regression was used for prediction of hospital admission (primary outcome), length of stay and supplemental oxygen requirement among those hospitalized, and antibiotic prescription (secondary outcomes).

We enrolled 3560 patients (N = 749 children, 2811 adults), 1405 (39%) with normal weight, 860 (24%) with overweight, and 1295 (36%) with obesity. Following multivariable logistic regression, very young or very old age (p < 0.001) and high-risk conditions (p < 0.001) predicted hospitalization. Risk of hospitalization was decreased for adults with overweight [aOR 0.8 (95% CI 0.6-1.0)], class 1 obesity [aOR 0.7 (95% CI 0.5-1.0)], and class 2 obesity [aOR 0.6 (95% CI 0.4-0.8)] compared to normal-weight. Class 3 obesity was associated with supplemental oxygen requirement in adults [aOR 1.6 (95% CI 1.1-2.5)]. No association was seen in children.

Overweight and obesity were not associated with increased risk of hospitalization during winter respiratory seasons in children or adults.