Elevated BMI Impairs Balance Among Older Adults with Vestibular Disorders

Each year, more than 2.5 million geriatric patients are admitted to emergency departments for fall-related injuries. Identifying variables that predict fall risk may help manage this problem. Physical activity and body composition are potential predictors. The average elderly fall risk patient walks \u3c2,200 steps per day and is commonly advised to minimize physical activity owing to elevated risk of injury. Limiting exposure can be effective in the short term but the chronic anthropometric consequences may exacerbate risk in the future. PURPOSE: To evaluate the effect of body mass index (BMI) on balance in geriatric patients who are at risk of falling. METHODS: We enrolled 24 patients (12 men, 12 women) with a diagnosed vestibular disorder who were ≥65 years of age. Patients were excluded if they had a history of injury precluding participation or currently participated in an exercise program. We collected demographic, anthropometric, and balance data at baseline. Balance was assessed using a CSMi HUMAC System Balance Board. After baseline testing, subjects were randomized to either a fatigue intervention (modified Bruce treadmill protocol) or a mild walking intervention (2 mph, 0% incline, 4 minutes). Following exercise, patients repeated the balance assessment. Linear regression tested the effects of age, sex, obesity, and group assignment on the change in balance score. RESULTS: The regression model explained 78% of the variance in the change in balance score (p\u3c0.001). Holding all other predictors constant, performing the fatigue protocol associated with a greater loss of balance (3.9 percentage points; p=0.044); for each 1-point increase in BMI, patients experienced an additional loss of 0.7 percentage points. When evaluating obesity as a binary variable, being classified as obese associated with a loss in balance of 5.0 percentage points (p=0.011). CONCLUSIONS: The relationship between fall risk and level of activity is complex. In our sample, obesity associated with a greater deterioration of balance following physical activity. When patients who are at risk of falling are advised to avoid physical activity, that advice may result in chronic compromise of balance, elevating the risk of future falls. Conversely, exercise performed in a safe, controlled environment may have therapeutic potential