Association between body mass index and the risk of falls: a nationwide population-based study

The association of BMI with falls differed between men and women in Korea. Obesity was associated with a greater risk of falls in women, whereas underweight seemed to increase the risk of falls compared with normal weight in men.

This study examined the sex-specific association between body mass index (BMI) and falls in Korean adults using data from a large population-based survey.

We analyzed 113,805 men and women (age ≥ 50 years) who participated in the Korean Community Health Survey in 2013. Logistic regression was used to assess the relationship between BMI and falls.

The mean (± standard deviation) age and BMI of all participants were 63.8 ± 9.6 years and 23.2 ± 2.9 kg/m², respectively. Among the 113,805 subjects, 19.1% and 6.7% had histories of falls and recurrent falls, respectively. The association of BMI with recurrent falls differed between men and women. The multivariable-adjusted odd ratios (ORs) for recurrent falls were 0.98 (95% confidence interval [CI] 0.86-1.12), 1.23 (1.14-1.32), and 1.51 (1.26-1.81) in women with BMIs of < 18.5, 25-29.9, and ≥ 30 kg/m², respectively, relative to those with BMIs of 18.5-24.9 kg/m². The corresponding ORs for men were 1.20 (95% CI 1.01-1.42), 1.05 (0.96-1.14), and 0.97 (0.69-1.38), respectively. Older age and low economic level were associated independently with higher ORs of recurrent falls in men and women, respectively. In addition, comorbidities, including diabetes, stroke, arthritis, osteoporosis, and asthma, correlated significantly with an increased risk of recurrent falls (all p < 0.001).

Obesity was associated with a greater risk of recurrent falls in women, whereas underweight seemed to be associated with a greater risk of falls in men.