Effect of Obesity on Falls, Injury, and Disability

Objectives: To examine the effect of obesity on the propensity of older adults to fall, sustain a fall-related injury, and develop disability in activities of daily living (ADLs) after a fall.

Design: Longitudinal population-based survey.

Setting: Five waves of the Health and Retirement Study (HRS), 1998-2006.

Participants: Ten thousand seven hundred fifty-five respondents aged 65 and older in 31,602 person-intervals.

Measurements: Falls within any 2-year interval (9,621 falls). Injuries requiring medical attention (3,130 injuries). Increased ADL disability after a fall within any 2-year interval (2,162 events). Underweight and three classes of obesity (body mass index (BMI) 30.0-34.9 kg/m(2) , Class 1) 35.0-39.9 kg/m(2) , Class 2; ≥40.0 kg/m(2) , Class 3), calculated from self-reported height and weight. Self-reported presence of lower body limitation, pain, dizziness, or vision problems. Self-reported doctor's diagnosis of diabetes mellitus, stroke, or arthritis.

Results: Compared with normal-weight respondents, the odds ratios (OR) for risk of falling were 1.12 (95% confidence interval (CI) = 1.01-1.24) for obesity Class 1, 1.26 (95% CI = 1.05-1.51) for obesity Class 2, and 1.50 (95% CI = 1.21-1.86) for obesity Class 3. Conditional on falling, only obesity Class 3 was related to a lower propensity for a fall-related injury (OR = 0.62, 95% CI = 0.44-0.87). Obesity Classes 1 and 2 were associated with a higher risk of greater ADL disability after a fall than normal-weight respondents (OR = 1.17, 95% CI = 1.02-1.34; OR = 1.39, 95% CI = 1.10-1.75, respectively). Being underweight was not related to risk of falling or to reported injury or greater ADL limitation after a fall. The presence of measured health problems and chronic conditions was associated with greater risk of falling and, of those who fell, greater ADL limitation but not serious injury.

Conclusion: Obesity appears to be associated with greater risk of falling in older adults, as well as a higher risk of greater ADL disability after a fall. Obesity (BMI ≥ 40 kg/m(2) ) may reduce the risk of injury from a fall. Further investigation of the mechanisms of obesity on falls and related health outcomes is warranted.