The clinical impacts of sleep apnea on mortality and allograft function in kidney transplant patients: A meta-analysis

Background: Sleep apnea (SA) is common in patients with advanced chronic kidney disease. However, its prevalence and clinical significance in kidney transplant patients are unknown. Objective: To demonstrate the clinical impacts of SA on kidney allograft and mortality from current evidence to date. Materials and methods: Ovid MEDLINE, EMBASE, and the Cochrane Library were searched for eligible publications. Kidney transplant recipients aged . 18 years with SA were included. The outcomes included overall mortality, graft failure, and graft loss. Graft loss was attributed by either 1) graft failure requiring renal replacement therapy (RRT)or 2) death. Results: Four observational studies (n = 5,259) were included in the meta-analyses. The mean age was 49.6 ± 0.4 years. Most patients were male (58.3%) and white (82.1%). Up to 25.1% had diabetes, 15.2% had SA, and 36.8% had history of smoking. The mean body mass index was 26.9 ± 0.9 kg/m2. With the mean follow-up duration of 14.4 ± 4.2 years, the pooled adjusted odds ratios (ORs) for graft failure and mortality among kidney transplant patients with SA were 1.061 (95% CI, 0.851-1.322; I2 = 41.3%) and 1.044 (95% CI, 0.853-1.278; I2 = 0%), respectively. The pooled adjusted OR for graft loss was 0.837 (95% CI, 0.597-1.173; I2 = 0%). On subgroup analyses, the ORs for graft failure were similar after adjusted by study year, country, study design, sample size, ethnicity, and sex. No potential publication bias was detected. Conclusion: With 14-year followup, SA in kidney transplant patients was not associated with worsening clinical and allograft outcomes, such as graft loss, graft failure, and mortality. However, additional observational studies are needed to confirm this finding.