The relationship between serum zinc level and prognosis of non-dialysis CKD patients.

BACKGROUND

Chronic kidney disease (CKD) constitutes a major public health challenge. Zinc deficiency is highly prevalent among CKD patients and is closely associated with the progression of kidney impairment. However, research focusing on serum zinc levels in non-dialysis chronic kidney disease (ND-CKD) patients remains limited.

METHODS

A single-center retrospective study was conducted on patients diagnosed with ND-CKD in the Department of Nephrology, General Hospital of Ningxia Medical University from October 2021 to December 2024. Participants were categorized into quartiles based on serum zinc levels, and clinical characteristics along with prognostic outcomes were compared across these groups.

RESULTS

The study included 206 ND-CKD patients. The median serum zinc level was 11.49(10.57,13.29) µmol/L. Over a median follow-up of 36 months, 46 patients (22.3%) experienced endpoint events. Comparative analysis revealed that ND-CKD patients with lower serum zinc levels had a significantly reduced survival rate (P < 0.05). Restricted Cubic Spline analysis confirmed a non-linear relationship between serum zinc levels and prognosis, as serum zinc levels increased, the hazard ratio(HR) gradually decreased and eventually plateaued or exhibited a slight increase (P < 0.001). Further analysis using a Trajectory model showed that the prognosis of high serum zinc level and slow decline group (class2) was significantly better than that of low serum zinc level and rapid decline group (class1) (P = 0.002, 0.23 (0.09, 0.58)).

CONCLUSION

In the subgroup of ND-CKD patients with clinical indications, low serum zinc level was independently associated with poor renal prognosis and was a significant predictor of clinical outcome. Serum zinc levels gradually decline as ND-CKD progresses, lower serum zinc levels are correlated with an increased risk of endpoint events and a poorer prognosis. However, as this is a single‑center retrospective study, the generalizability of the findings may be limited, and prospective multicenter validation is needed.