P040 Identifying key OSA predisposing factors in non-Caucasian populations of Australia

Abstract Introduction Obstructive sleep apnoea (OSA) is linked to obesity, daytime sleepiness, cardiovascular disease, type 2 diabetes mellitus, and increased accident risk.1,2 While traditional risk factors are well-studied in Caucasians, data on non-Caucasian Australians remains limited, despite higher cardiovascular risks.3 Emerging evidence suggests OSA in these groups may involve factors beyond obesity alone. This study compares key OSA predictors across ethnic groups within our health service to support more equitable and targeted screening. Methods We retrospectively analysed records of adults (≥18 years) who underwent diagnostic sleep studies in 2022-2023 at a local tertiary public hospital and private sleep clinic in Queensland, Australia. The association between traditional OSA predictors and AHI (apnoea-hypopnoea index) in Caucasians and non-Caucasians was determined with linear regression. Results Among 2181 patients, 77% had OSA (31% mild, 23% moderate, 32% severe). Median age was 50 years (IQR 39-61); 60% were male. BMI (body mass index) significantly predicted AHI in both groups, with a stronger effect in non-Caucasians; Asian population showed the strongest BMI-AHI association (1.8units per BMI point; p<.001). BMI threshold for moderate-to-severe OSA was lower in non-Caucasians (28kg/m2). Male sex and hypertension were also linked to higher AHI. Discussion Our findings suggest a trend toward greater OSA severity in non-Caucasian patients at lower BMIs, with gender and hypertension also emerging as potential predictors in these groups. These patterns highlight the need for ethnicity-specific screening thresholds and risk-assessment strategies. Further research should evaluate the performance of tools like STOP-BANG and Epworth Sleepiness Scale in diverse populations to enhance diagnostic accuracy and equity.