Performance of urinary vitamin D-binding protein in diabetic kidney disease: a meta-analysis

Abstract

Objective To systematically evaluate the correlation between urinary vitamin D-binding protein (VDBP) and diabetic kidney disease and to evaluate the relationship between urinary VDBP and the albumin-to-creatinine ratio (ACR), renal function indicators [estimate glomerular filtration rate (eGFR), creatinine (CR), blood urea nitrogen (BUN)] and glycaemic control indices [glycated hemoglobin (HbA1c), fasting plasma glucose (FPG)]. Methods We searched the CNKI, Wanfang, VIP, CBM, PubMed, Cochrane Library, Embase and Web of Science databases up to May 31, 2023, for relevant literature. RevMan 5.3 software was used for the meta-analysis. Results Ultimately, 9 articles were included. Due to heterogeneity in the pooled results, the random-effects model was chosen. Meta-analysis results showed that the urinary VDBP concentrations in the normal albuminuria diabetes group were significantly higher than those in the healthy control group [SMD 1.52, 95% CI (0.84, 2.19), p < 0.00001]. The urinary VDBP concentrations in the microalbuminuria diabetes group were significantly higher than those in the normal albuminuria diabetes group [SMD 1.81, 95% CI (1.40, 2.21), p < 0.00001]. The urinary VDBP concentrations in the macroalbuminuria diabetes group were also significantly higher than those in the microalbuminuria diabetes group [SMD 1.51, 95% CI (1.05, 1.96), p < 0.00001]. In addition, urinary VDBP was positively correlated with the ACR, CR, BUN and HbA1c [Summary r = 0.73, 95% CI (0.54, 0.85), p < 0.0001; Summary r = 0.38, 95% CI (0.10, 0.61), p = 0.009; Summary r = 0.37, 95% CI (0.16, 0.55), p = 0.0008; Summary r = 0.40, 95% CI (0.13, 0.62), p = 0.005, respectively] and tended to be negatively correlated with the eGFR [Summary r = −0.64, 95% CI (−0.92, 0.10), p = 0.08] but was not significantly correlated with the FPG [Summary r = 0.16, 95% CI (−0.03, 0.33), p = 0.10]. Sensitivity analysis showed that our pooled results are robust. Conclusion Urinary VDBP may be used as a novel biomarker for the early diagnosis of DKD and can be used to assess the severity of DKD.

Urinary Vitamin D Binding Protein: A Marker of Kidney Tubular Dysfunction in Patients at Risk for Type 2 Diabetes

“…Overall, there has been a very limited number of studies that have examined the relationship between uVDBP with established kidney biomarkers. In particular, studies with humans have used cross-sectional designs and have involved very few participants [ 27 ]. The present study is a pioneering effort to investigate the associations between uVDBP, ACR, and eGFR in a large prospective cohort at multiple time points over 6 years.…”

“…Tian et al and Khodeir et al both reported that uVDBP levels were significantly elevated in patients with type 2 diabetes mellitus (T2DM) with microalbuminuria and T2DM with macroalbuminuria compared to controls with T2DM and normoalbuminuria [ 21 , 25 ]. However, these studies have been limited by cross-sectional designs and small sample sizes [ 27 ]. In addition, the utility of uVDBP to predict declines in kidney function over time has not been examined.…”