Obesity linked with improved survival in pneumonia patients

A study recently conducted found that Pneumonia patients who are obese and overweight are 20-30 percent less likely to die than patients of a normal weight.

The study, conducted by the European Association for the Study of Obesity, used the Nationwide Readmission database of the United States from 2013 to 2014 to identify patients hospitalised with pneumonia.

Use of mechanical ventilation was used to stratify pneumonia of different severity. Hospitalised pneumonia patients were categorised into normal (body mass index [BMI] under 25), overweight (BMI between 25 and 30), and obese (BMI over 30).

To minimise baseline differences between patients with different body weight, the authors carried out a technique call propensity score (PS)-matched analysis. PS contains 41 variables including demographics, social economic status, chronic comorbidities, and severity of pneumonia.

Patients were matched 1:1:1 using this technique across the three groups of normal weight, overweight and obese. The authors then used computer modelling on the PS-matched pairs to assess the association between body weight and 30-day in-hospital mortality.

A total of 1,690,760 pneumonia hospitalisation episodes fulfilled the inclusion criteria, of which 17,992 were overweight, 195,889 were obese, and 1,476,879 were normal weight.

Compared with normal weight patients without the use of a ventilator, overweight patients were 23 percent more likely to survive and obese patients 29 percent more likely to survive.

Similar results were obtained in the cohort of more serious pneumonia requiring the use of ventilator -- overweight and obese patients were 21 percent and 30 percent respectively more likely to survive than normal-weight patients (see table 1 full abstract).

"Using a large and nationally representative sample of over 1,000 hospitals in the US, we found that increase in body mass index was significantly associated with improved survival in patients hospitalised with pneumonia. We also found that severity and comorbidity burden had a modifying effect on survival," concluded the authors.

The study was presented at the European Congress on Obesity in Vienna, Austria.