Obstructive sleep apnoea is associated with accelerated progression of diabetic kidney disease

Persons with type 2 diabetes and diabetic kidney disease (DKD) are at high risk of end-stage kidney disease or death. We investigated the possible contribution of obstructive sleep apnoea (OSA) to decline in kidney function and renal outcomes.

About 120 participants with estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² (not on renal replacement therapy [RRT]) and elevated urine albumin-creatinine ratio (UACR) were evaluated for OSA using the apnoea-hypopnea index (AHI) determined by the portable home sleeping device ApneaLink+. Forty-one participants without OSA (AHI <5) were compared with 36 with moderate-to-severe OSA (AHI ≥15). With the date of OSA assessment defined as index, data on UACR and eGFR were sampled from 5 years prior to index and until end-of-follow-up (median 3.2 years from index).

At index, age, eGFR (32.2 vs. 32.9 mL/min/1.73 m²), medication, blood pressure, lipid levels, and glycaemic control were comparable between the two groups, but participants with OSA had higher body mass index (BMI) and UACR. The eGFR decline from -5 years to end-of-follow-up (adjusted for age, sex and UACR at -5 years) was larger in OSA than non-OSA participants (p = 0.016). Participants with OSA were at increased risk of CKD progression (eGFR decline >50% or RRT, adjusted hazard ratio 3.4, 95% CI: 1.3-9.1), robust to adjustment for age, sex, eGFR, UACR, BMI and blood pressure. The combined endpoint of CKD progression or death also occurred more often among OSA participants (adjusted hazard ratio 3.2 [1.3-7.7]).

Our results suggest OSA to be an important and independent contributor to the progression of DKD.