Correlation of Body Composition Parameters Derived From Bioelectrical Impedance Analysis With Obstructive Sleep Apnea Severity in Adults

Background and Objective Although obesity and a high body mass index (BMI) are known risk factors for obstructive sleep apnea (OSA), BMI may not fully capture true adiposity. True adiposity is better assessed via body fat percentage, increased abdominal fat, or low lean muscle mass. This study uses bioelectrical impedance analysis (BIA) to evaluate these factors as OSA indicators.Methods Adult patients visiting an otolaryngology clinic for snoring or sleep apnea were recruited following in-laboratory Level I polysomnography. Prior surgeries or neurological disorders were excluded. InBody 270 was used to measure body fat percentage, skeletal muscle mass, and abdominal fat ratio (ABF). Polysomnography and BIA parameters were analyzed for overall and subgroup correlations.Results Thirty-four OSA patients (mean age 52.3±14.2 years; 79.4% male; 73.5% severe OSA) were included. The apnea–hypopnea index (AHI) correlated significantly with BMI, body fat mass, body fat percentage, ABF, and abdominal circumference (all R=0.5–0.7, p<0.05). AHI was inversely correlated with skeletal muscle percentage (R=-0.57, p<0.001). Similarly, the percentage of time with oxygen saturation below 90% (T90) positively correlated with adiposity metrics and inversely with skeletal muscle percentage (R=-0.67, p<0.001). Multivariable regression showed ABF and body fat percentage were stronger independent predictors for AHI and T90, respectively, than BMI.Conclusions In adult OSA, disease severity (AHI) and nocturnal hypoxemia (T90) independently correlate with BIA-derived abdominal fat and body fat percentage, outperforming BMI. BIA serves as a valuable point-of-care tool for risk stratification.