Obstructive sleep apnoea, a risk factor for cardiovascular and microvascular disease in patients with type 2 diabetes mellitus: findings from a population-based cohort study

<div><b>Objective</b>: To determine risk of cardiovascular diseases (CVD), microvascular complications and mortality in patients with type 2 diabetes who subsequently develop obstructive sleep apnoea(OSA) compared to patients with type 2 diabetes without a diagnosis of OSA.</div><div><b>Research Design and Methods</b>: An age-, sex-, body mass index- and diabetes duration-matched cohort study using data from a UK primary care database from 01/01/2005 to 17/01/2018. Participants aged ≥16 years with type 2 diabetes were included. Exposed participants were those who developed OSA after their diabetes diagnosis; unexposed participants were those without diagnosed OSA. Outcomes were composite CVD (ischaemic heart disease(IHD), stroke/transient ischaemic attack(TIA), heart failure(HF)); peripheral vascular disease(PVD); atrial fibrillation(AF); peripheral neuropathy(PN); diabetes-related foot disease(DFD); referable retinopathy; chronic kidney disease(CKD); all-cause mortality. The same outcomes were explored in patients with pre-existing OSA before a diagnosis of type 2 diabetes versus diabetes without diagnosed OSA.</div><div><b>Results</b>: 3,667 exposed participants and 10,450 matched controls were included. Adjusted hazard ratios for the outcomes were: composite CVD 1.54(95%CI 1.32,1.79); IHD 1.55(1.26,1.90); HF 1.67(1.35,2.06); stroke/TIA 1.57(1.27,1.94); PVD 1.10(0.91,1.32); AF 1.53(1.28,1.83); PN 1.32(1.14,1.51); DFD 1.42(1.16,1.74); retinopathy 0.99(0.82,1.21); CKD (stage 3-5) 1.18(1.02,1.36); albuminuria 1.11(1.01,1.22); all-cause mortality 1.24(1.10,1.40). In the prevalent OSA cohort the results were similar but some associations not observed.<br></div><div><b>Conclusions</b>: Patients with type 2 diabetes who develop OSA are at increased risk of CVD, AF, PN, DFD, CKD, and all-cause mortality compared to patients without diagnosed OSA. Patients with type 2 diabetes who develop OSA are a high-risk population and strategies to detect OSA and prevent cardiovascular and microvascular complications should be implemented.</div>