Obstructive sleep apnea (OSA) is highly prevalent in chronic kidney disease (CKD) patients and strongly linked to obesity, metabolic syndrome, and type 2 diabetes. Besides elevating cardiovascular disease risk, OSA may worsen renal function and diminish quality of life, making its understanding critical for CKD patient health. This study will establish a large, long-term cohort of non-dialysis CKD patients to identify OSA risk factors, explore OSA's association with adverse renal outcomes, and determine OSA prevalence and epidemiological characteristics within the CKD population. The findings will provide a scientific foundation for early OSA identification, diagnosis, and intervention in CKD patients.