Abstract
BACKGROUND: Disturbances in calcium (Ca), vitamin D, and electrolyte balance have been implicated in diabetic kidney disease (DKD), yet existing evidence remains inconsistent. Moreover, the role of albumin-corrected Ca-a more accurate measure of biologically active Ca in patients with frequent hypoalbuminemia-remains poorly defined in type 2 diabetes mellitus (T2DM). We aimed to investigate the association between albumin-corrected Ca, vitamin D, electrolytes and DKD in a large T2DM cohort. METHODS: In this cross-sectional study, 5550 T2DM patients were enrolled, including 1574 participants with DKD. Multivariable regression analyses were used to assess the association between albumin-corrected Ca, vitamin D and DKD. Spearman's correlation analyses were conducted to examine the correlation between electrolyte levels, vitamin D and indicators of renal impairment. RESULTS: Patients with DKD in T2DM were older, predominantly male, with longer diabetes duration, higher blood pressure, poorly glycemic control and more diabetic complications compared to those without DKD. Notably, patients with DKD also showed significant electrolyte imbalances, suggesting dysregulated mineral metabolism. Multivariate logistic regression revealed albumin-corrected Ca (odds ratio [OR]: 4.032, 95% confidence interval [CI]: 2.017-8.062, P < 0.001), 1,25-(OH)(2)-VitD(3) (OR: 0.967, 95% CI: 0.960-0.974, P < 0.001) were independently associated with DKD after accounting for confounding factors. CONCLUSIONS: We demonstrated that elevated albumin-corrected Ca and decreased 1,25-(OH)(2)-VitD(3) were significantly associated with DKD in T2DM patients. These findings suggest the potential of mineral metabolism parameters, particularly albumin-corrected Ca, to enhance early detection and risk stratification. Future prospective cohort studies are essential to establish a causal relationship and clarify their clinical therapeutic guidance value.