Australian Aboriginal and Torres Straight Islanders (ATSI) are noted to have a higher burden of chronic health conditions. However, there is a paucity of data on Obstructive Sleep Apnoea (OSA) in this population. In this retrospective study, we evaluated the clinical and polysomnographic (PSG) characteristics of ATSI and non- ATSI adult patients who underwent diagnostic PSG between 2011 and 2015. There were a total of 3078 patients. Of the total, 403 (13%) were of ATSI origin. Amongst those of ATSI origin, 61% were male and 39% females, while amongst the non-ATSI cohort, 66% were males. The median age was 47.8 years in ATSI and 51.5 years in the non- ATSI cohort. In the combined cohort, body mass index was >30 kg/m2 ( 61%), hypertension (14.4%), diabetes ( 17.8%) and heart disease ( 23.3%). The ATSI patients had higher rates of class III obesity (27 v 15%), hypertension (26 v 14%), cardiac disease (34 v 23%) and diabetes (37 v 17%). Among all the study participants, the PSG confirmed 83.7% of the patients had an apnoea-hypopnea index (AHI) more than 5/hour, mild (AHI 5-15/hour) in (28.4%), moderate (AHI 15-30/hour) in (22.3%), and severe (AHI > 30/hour) in (33.0%). Among the ATSI patients, 46% had severe OSA. The median total AHI value was higher in the ATSI population (25, IQR: 11 – 58) compared to the non-ATSI (17, IQR: 7 – 36), and in rural/remote population (19, IQR: 8 – 42) compared to urban (17, IQR: 7 – 37). This trend was similar for NREM (Non Rapid Eye Movement)-AHI and REM (Rapid Eye Movement) AHI scores, although statistically significant difference was found only with ATSI status. In the combined cohort the probability of (OR= 1.62, 95% CI: 1.32-2.00, p<0.001) of severe OSA was 62% higher in individual with hypertension , however, when stratified by ATSI status, the association was only significant in the non-ATSI population (OR=1.53 95% CI: 1.21 – 1.94, p<0.001). The odds of severe AHI was also significantly associated with heart disease (1.37; 95%CI: 1.14,1.63, p<0.001), diabetes (1.74; 95%CI: 1.43,2.10; p<0.001) and smoking (1.28; 95%CI: 1.09,1.50, p=0.0023) in the overall study cohort. In both ATSI and non- ATSI patients, BMI, neck circumference, sleep efficiency, wake after sleep onset and respiratory arousal index were significantly higher and independently associated with severe AHI.
Heraganahally, S. S., Kruavit, A., Oguoma, V., Chandran, G., Mehra, S., Judge, D., & Sajkov, D. (2020). Sleep apnoea among Australian Aboriginal and Non- Aboriginal patients in the Northern Territory of Australia– a comparative study. Sleep, 43(3), 1-11. https://doi.org/10.1093/sleep/zsz248