Obstructive sleep apnoea and long-term risk of incident diabetes in middle-aged and older general population

Abstract

Obstructive sleep apnoea (OSA) is associated with increased risk of type-2 diabetes. However, results from large population-based prospective cohort studies are rare. The main aim of the present study was to investigate the relative risk (RR) of 8-year incident type-2 diabetes in relation to OSA severity in a prospective cohort study of middle-aged and older adults. A total of 2,918 participants (avg. age of 59 years) of the Korean Genome and Epidemiology Study (KoGES), who underwent homebased overnight polysomnography at baseline examination between year 2011 and 2014, were followed up 4-yearly between 2015–2018 and 2019–2021. A total of 1,697 participants were present in both the follow-ups. After excluding participants who had diabetes at baseline (n=481), a total of 1,216 participants were eligible for the analyses. OSA at baseline were categorized by apnoea–hypopnoea index (AHI) levels as non-OSA (0–4.9 events·h⁻¹), mild OSA (5.0–14.9 events·h⁻¹) and moderate-severe OSA (≥15.0 events·h⁻¹). Incident type-2 diabetes was identified at each follow-ups. Compared to non-OSA, participants with moderate-severe OSA had 1.5 times higher risk of developing type-2 diabetes at the end of 8-year follow-up after adjusting for potential covariates (RR=1.50, 95% confidence interval=1.02–2.21). In the same analytical models for 4-year RR of incident type-2 diabetes, none of the OSA groups were in significantly higher risk compared to non-OSA group. Moderate-severe OSA, a modifiable risk factor, poses a higher risk of incident type-2 diabetes compared to non-OSA group over 8-year period in general middle-aged and older adults.