0545 From Waist to Calf: Mapping the Anthropometric Anatomy of Hypoxic Burden

Abstract Introduction Hypoxic burden (HB) integrates the depth, duration, and frequency of oxygen desaturations and may reflect cardiometabolic risk in Obstructive Sleep Apnea (OSA). Objective: To evaluate the relationship between anthropometric measurements, HB, and the oxygen desaturation index (ODI) in OSA. Methods A cross-sectional analysis was performed in 36 patients, 58.1% women, mean age 53.95 + 11.86 years. Measurements included Body Mass Index (BMI), ODI, cervical circumference (CC), abdominal circumference (AC), calf circumference (CaC), and HB, calculated as the area under the curve of desaturations > 3%. Results The sample presented a mean and standard deviation for BMI of 30.77 + 8.06, for cervical circumference of 38.51 + 4.38, for abdominal circumference of 103.59 + 13.56, for ODI of 20.65 + 41.29, and for hypoxic burden of 51.30 (ranging from 14.93 to 88.15). The sleep ODI percentile was equivalent to 6.9 (ranging from 1.75 to 18.08). A positive correlation was observed between: AC and HB (r = 0.662; p = 0.001), AC and sleep ODI (r = 0.799; p = 0.000), AC and BMI (r = 0.729; p = 0.000); CC and AC (r = 0.384; p = 0.025); and AC and CC (r = 0.510; p = 0.002). The mean of the variables was evaluated according to the abdominal circumference measurement (AC greater than 130 cm vs AC less than 130 cm, respectively), showing: Age (54.41 + 10.46 vs 51.00 + 20.14; p = 0.729), BMI: (30.17 + 7.56 vs 35.25 + 11.53; p = 0.449), CC (37.4 + 3.39 vs 44.67 + 9.29; p = 0.336), CaC (37.94 + 8.59 vs 41.00 + 4.24; p = 0.480), AC (101.78 + 11.76 vs 132.50 + 2.12; p = 0.000), and ODI (12.85 + 13.03 vs 98.65 + 138.52; p = 0.537). Sleep ODI: (11.59 + 14.09 vs 102.85 + 145.17; p = 0.537), HB (58.26 + 45.90 vs 441.15 + 618.22; p = 0.02). Conclusion AC showed the strongest association with HB, indicating central adiposity better reflects hypoxemia severity than BMI. The data suggest abdominal measures may support risk assessment in OSA. Support (if any)