Clinically Significant Obstructive Sleep Apnea as a Predictor of Kidney Transplant Outcome: Systematic Review and Meta-Analysis

Background: Obstructive sleep apnea (OSA) is a well described risk factor for cardiovascular and metabolic dysfunction, and progression of kidney disease. In kidney transplant recipients (KTRs), OSA may contribute to worse outcomes. However, the extent to which OSA affects KTRs outcomes, and how rapidly these changes occur is unclear. This systemic review and meta-analysis investigates how clinically significant OSA (Apneic hypoxic index “AHI” ≥ 15) impacts transplanted kidney estimated glomerular filtration rate (eGFR). Methods: Systematically searched Scopus, Pubmed, Cochrane library, and CINAHL from inception to March 13th, 2025. Eligible studies included adult KTRs comorbid with OSA. Of 489 screened studies, 14 met initial inclusion, with 9 later excluded due to inconsistent OSA definitions. Primary outcomes of eligible studies included eGFR and creatinine. Student’s t test compared differences in renal function measures in between OSA groups. A linear regression was used to examine the rate at which kidney function was affected depending on AHI. Results: Eligible studies included a total of 764 patients, which were stratified into clinically significant OSA and non-clinically significant OSA. Renal function measures (eGFR and creatinine) alongside general parametric information (BMI, age, etc.) were obtained. Average follow-up time was 63 months ± 22 months. There was a significant difference (P < 0.0001) in reported eGFR between the clinically significant OSA group and non-clinically significant OSA group. Regression analysis also demonstrated a stronger inverse relationship between AHI and eGFR in the clinically significant OSA group. Conclusion: Clinically significant OSA may be linked to adverse KTRs outcomes. Although a stronger correlation of higher AHI and eGFR decline was observed, it did not reach statistical significance possibly due to relatively short follow-up time. Longer term studies are needed to better describe the potential risk of OSA on KTRs outcomes. Comparison Between Clinically Significant OSA Against Not Clinically Significant OSA - AHI < 15 AHI ≥ 15 Δ P value eGFR (mL/min/1.73m2) 44.737 (30.370 - 59.104) 39.775 (25.454 - 54.096) -4.962 P < 0.0001 Creatinine (mg/dL) 3.584 (2.658 - 4.509) 5.204 (0.830 - 9.578) 1.62 P < 0.0001 BMI 26.035 (25.362 - 26.708) 28.750 (27.906 - 29.593) 2.715 P < 0.0001 Age 48.672 (46.166 - 51.179) 55.594 (53.700 - 57.488) 6.922 P < 0.0001