Objectives: To investigate the association between body mass index (BMI) and the risk of nonfatal body injury.
Methods: We analyzed data from 113,203 adults who participated in the Canadian Community Health Survey conducted in 2009-2010. Log-binomial models were used to estimate crude and adjusted relative risks of the association between BMI and the risk of body injury for men and women.
Results: Of 113,203 adult participants, 15,194 had self-reported body injuries during the past 12 months, with a 12-month cumulative incidence of 13.7% (weighted to Canadian population). There was a significant interaction between gender and BMI in relation to the risk of body injury, and therefore, analyses were stratified by gender. For women, we found a significant association between BMI and an increased risk of body injury. Women with an increased BMI had a significant increased risk of body injuries as compared with those with normal weight (adjusted relative risk: 1.13, 95% confidence interval (CI)=1.02-1.25 for BMI 30.0-34.9 kg m(-)(2); 1.17, 95% CI=1.00-1.37 for BMI 35.0-39.9 kg m(-)(2); 1.41, 95% CI=1.16-1.69 for BMI ⩾ 40 kg m(-)(2)). A reduced risk of injury was observed in underweight women. There was no significant association between BMI and the risk of body injury for men. Obese persons of both gender were more likely to suffer injuries to the knee and lower leg, and in less demanding activities such as household chores or using the stairs.
Conclusions: We therefore conclude that increased BMI may be a risk factor for body injury in women, but not in men.