Update on the epidemiology of obstructive sleep apnea syndrome in Central Eastern Tunisia over 11 years.

Introduction: obstructive sleep apnea syndrome (OSAS) is the most common sleep-related breathing disorder. Knowledge about OSAS incidence trends could be extremely useful in assessing health needs and implementing preventive measures accordingly. This study aimed at the epidemiological and clinical specificities of OSAS and to give an update on its current chronological trends.

Methods: we conducted a retrospective study including all cases of OSAS diagnosed over 11 years, from January 1, 2012, to December 31, 2022, at the Sleep Unit of the Neurophysiology Department of the Sahloul University Hospital, Tunisia.

Results: overall, 848 new cases of OSAS were diagnosed. The mean annual number of OSAS cases was 74.8/year. The crude incidence rate (CIR) was 12.3/100000 inhabitants/year, it was significantly increasing over the years (rho=0.7; p=0.01). The median age was 56 (IQR= [48-64]) years, it increased significantly during the study period from 54 years (IQR= [43-63]) in 2012 to 58 years (IQR= [50.5-65]) in 2022 (rho=0.7; p=0.015). The median BMI was 35.5 (IQR= [31.3-40.3]) kg/m. The median BMI of patients diagnosed with OSAS increased significantly from 34.6 kg/m to 38.3 kg/m (rho=0.75; p=0.008). This equated to an annual increase in median BMI of 0.41 kg/m. The median AHI showed a significant upward trend for all patients, rising from 26.30 events/h in 2012 to 34.07 events/h in 2022 (rho=0.68; p=0.02).

Conclusion: the CIR of OSAS is related to BMI and age. Thus, we assume that it will continue to increase in the coming years with the rise in obesity and the aging of the population.