Identification of risk factors and development of a predictive model for early renal impairment in patients with obstructive sleep apnea-hypopnea syndrome

OBJECTIVE: This study aims to identify independent risk factors associated with early renal impairment in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) and to develop a predictive model for individualized risk stratification. METHODS: This retrospective cross-sectional study included 259 patients with a confirmed diagnosis of OSAHS based on overnight polysomnography (PSG). Participants were classified into two groups based on urine albumin-to-creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR): a normal renal function group (n = 173) and an early renal impairment group (n = 86). Data on demographic variables, clinical comorbidities, PSG-derived indices, and laboratory parameters were collected. Univariate and multivariate logistic regression analyses were performed to identify independent predictors of early renal impairment. A nomogram was subsequently developed, with its performance assessed using receiver operating characteristic (ROC) curve analysis, the Hosmer-Lemeshow goodness-of-fit test, decision curve analysis (DCA), and bootstrap internal validation. RESULTS: Multivariate analysis identified elevated body mass index, presence of hypertension and diabetes mellitus, increased cumulative time with oxygen saturation below 90%, higher levels of high-sensitivity C-reactive protein, and elevated serum cystatin C as independent risk factors for early renal impairment. Conversely, higher minimum nocturnal oxygen saturation was identified as a protective factor. The constructed nomogram demonstrated good discriminatory capacity (area under the ROC curve = 0.796) and calibration (Hosmer-Lemeshow test, p = 0.231). DCA supported its clinical utility within a predicted probability range of 0.2-0.8. CONCLUSION: Early renal impairment in patients with OSAHS is significantly associated with obesity, cardiometabolic comorbidities, hypoxemia-related burden, and systemic inflammation. The developed nomogram showed acceptable discrimination and calibration and may serve as a preliminary tool for individualized risk stratification in patients with OSAHS.