Impact of continuous positive airway pressure therapy on metabolic and renal parameters in patients with obstructive sleep apnea, type 2 diabetes mellitus, and chronic kidney disease: a prospective cohort study.

BACKGROUND

Continuous positive airway pressure (CPAP) therapy is the gold standard treatment for obstructive sleep apnea (OSA), but its impact on type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD), remains unclear. This study aimed to evaluate the effects of CPAP therapy on metabolic and renal parameters in patients with OSA, T2DM, and CKD for over 18 months.

MATERIAL AND

METHODS

This prospective, non-randomized, single-centre cohort study enrolled 60 patients with moderate-to-severe OSA (AHI > 15 episodes/hour), CKD (eGFR 15-60 mL/min/1.73m2), and T2DM. The patients were divided into a CPAP therapy group (n = 30) and a usual care group (n = 30). CPAP adherence was defined as ≥ 4 h/night for at least 70% of monitored nights. The primary outcomes included changes in the urinary albumin-to-creatinine ratio (UACR) Secondary outcomes included changes in serum creatinine, estimated glomerular filtration rate (eGFR), HbA1c, homeostasis model assessment of insulin resistance (HOMA-IR), apnea-hypopnea index (AHI), and oxygen desaturation index (ODI). Statistical analyses included independent test, repeated measures of analysis of variance, and analysis of covariance (ANCOVA).

RESULTS

8 (13%) patients were lost to follow-up, and therefore 52 patients (27 patients in CPAP group and 25 patients in usual care group) were included in per-protocol analysis. After 18 months, CPAP therapy significantly improved AHI (mean change: 8.96 ± 4.94, p = 0.001), HbA1c (mean change: 1.44 ± 0.46, p = 0.001), HOMA-IR (mean change: 1.85 ± 0.14, p = 0.001), UACR (mean change: 139.08 ± 85.27 mg/g, p = 0.015), and serum creatinine (mean change: 1.02 ± 0.34 mg/dL, p = 0.011). No significant changes were observed in eGFR (p = 0.513) levels.

CONCLUSION

CPAP therapy significantly improved metabolic and renal parameters, particularly albuminuria and insulin resistance, in patients with OSA, T2DM, and CKD. However, it did not significantly impact the eGFR over 18 months.