A Nonlinear Relationship Between Serum 25-Hydroxyvitamin D and Urine Albumin to Creatinine Ratio in Type 2 Diabetes: A Cross-Sectional Study in China

Abstract

Background: Diabetic kidney disease often presents as increased urine albumin to creatinine ratio (UACR). 25-hydroxyvitamin D (25(OH)D) is considered as the best indicator of vitamin D status. Previous studies have shown that 25(OH)D is related to the UACR. However, evidence concerning the connection between 25(OH)D and UACR is still limited in the Chinese population. Materials and Methods: A total of 549 participants with type 2 diabetes were enrolled in the study from Shenzhen People's Hospital, China. The participants were grouped by the tertiles of 25(OH)D level. The association between 25(OH)D and UACR was examined by multiple linear regression. A generalized additive model (GAM) was used to verify a nonlinear relationship. We conducted a subgroup analysis to evaluate the robustness of the results. Results: After adjusting for relevant variables, 25(OH)D was negatively correlated with UACR (β = −8.7, 95% CI (−12.0, −5.4)). A non-linear relationship was discovered between 25(OH)D and UACR, and the 25(OH)D threshold was 67. The effect sizes and confidence intervals on the left and right sides of the inflection point were −13.9 (−18.2, −9.6) and 8.9 (−1.1, 18.9), respectively. Subgroup analysis showed a stronger correlation could be detected in males. The same trend also could be found in patients older than 70 years old, those with using ACEI/ARB, with history of hypertension, with SBP ≥140 mmHg and eGFR <60 mL/ min/1.73m 2 . Conclusion:The relationship between 25(OH)D and UACR is non-linear. 25(OH)D was negatively related to UACR when 25(OH)D is less than 67 nmol/L.

The Role of Vitamin D, DKK1, Hepcidin and Oxidative Stress Biomarkers in Type 2 Diabetes Mellitus Patients With and Without Diabetic Nephropathy

“…In agreement with our results, Alatawi et al (19) elucidated that diabetic rats showed a significant decrease in SOD and GPx but a significant elevation in MDA, the situation was reversed after treatment of diabetic rats with vitamin D supplementation indicating that vitamin D played a crucial role in the protection of tissues from damage by free radicals. Furthermore, we noticed inverse relationship between vitamin D and UACR, a finding supported by Liang et al (20) .…”

Association of Serum 25 (OH) Vitamin D With Chronic Kidney Disease Progression in Type 2 Diabetes

“…Previous studies were mainly focused on T2DM population to explore the relationship of VD levels and the presence of DKD ( 12 , 13 , 28 ). Recent studies have indicated that hypovitaminosis D was associated with a higher risk of developing DKD in T2DM ( 15 ).…”

“…In addition, it plays a vital role in modulating cell proliferation, apoptosis, differentiation, inflammation response, immune function, and vascular and metabolic properties such as insulin secretion and insulin sensitivity (8)(9)(10). 25hydroxyvitamin D [25(OH)D] is synthesized by 25-hydroxylase catalyzing VD, which is considered as the best indicator of VD status (11,12). In recent years, lower serum 25(OH)D level has been implicated in the incidence of T2DM, which may rely on its association with impaired glucose and insulin metabolism (12,13).…”

“…25hydroxyvitamin D [25(OH)D] is synthesized by 25-hydroxylase catalyzing VD, which is considered as the best indicator of VD status (11,12). In recent years, lower serum 25(OH)D level has been implicated in the incidence of T2DM, which may rely on its association with impaired glucose and insulin metabolism (12,13). More importantly, VD deficiency increases the risk of T2DM development and the incidence of its complication (14,15).…”

Vitamin D and Diabetic Kidney Disease

“…Patients with DKD are more likely to be vitamin D deficient than those without DKD [ 6 , 108 , 109 , 110 , 111 , 112 , 113 , 114 , 115 ]. A cross-sectional study involving 300 patients with diabetes found that CKD was significantly associated with vitamin D deficiency ( p = 0.043).…”