Increased Risk of Bacterial Infections among the Obese with Chronic Diseases

It has been well understood that cigarette smokers have an increased risk of infections; however, the association between obesity and infections has not been well explored in general population.

The analysis was based on data from the Canadian Community Health Survey - Healthy Aging (2008-2009), and included a total of 30 763 Canadians aged 45 years or older. Information on demographic data, body mass index (BMI), smoking status, chronic condition(s) and antibiotics use during the past month were collected. Logistic regression analysis was used to determine the associations of obesity and smoking with antibiotics use and adjusted for potential confounders.

Overall, 6.6% used antibiotics in the previous month. Compared with those of normal weight, overweight and obese individuals were more likely to use antibiotics after adjustment for confounders, with odds ratios (ORs) of 1.28 (95% CI: 1.08, 1.50) and 1.25 (95% CI: 1.04, 1.50), respectively. When stratified by presence/absence of chronic condition(s), the associations were only significant among those with chronic condition(s) and the adjusted ORs were 1.30 (95% CI: 1.09, 1.55) for the overweight and 1.43 (95% CI: 1.18, 1.73) for the obese. Current smokers had an increased risk of antibiotics use when compared with non-smokers. The adjusted OR for smoking was similar for people with or without chronic condition(s), but was significant only for those with chronic condition(s) (OR 1.41, 95% CI: 1.16, 1.73).

Overweight and obese Canadians aged 45 years or more, especially in those with chronic condition(s), had an increased risk of bacterial infections than their normal weight counterparts. The reasons for the modifying effect of chronic condition(s) on the association between body weight and infections were discussed.