Body mass index as a surrogate measure of obesity in the chronic spinal cord injury population
Background. Body mass index does not capture obesity or cardiovascular disease risk in small, limited samples of people with SCI. Objectives. (1) To determine sensitivity of the current BMI cut-off for obesity in a representative sample of persons with SCI; (2) To explore the feasibility of developing a more sensitive BMI cut-off for obesity based on percent fat mass (%FM) and C-reactive protein (CRP). Methods. A cross-sectional study of 77 adults with chronic SCI involved collection of anthropometric and biological data. Statistical analyses included sensitivity analyses, piecewise regression, non-linear regression, and receiver operator characteristic curves. Results. BMI cut-off of 30 kg/m2 fails to identify 79.5% of obese participants compared to 26.1% at 25 kg/m 2. BMI cut-offs determined from risk levels of %FM and CRP ranged from 22.1 kg/m2-26.5 kg/m2. Conclusions. People with SCI and BMI values greater than 22 kg/m2 should be identified as at high risk for chronic disease.