The Association of Vitamin D Status and Vitamin D Replacement Therapy with Glycemic Control, Serum Uric Acid Levels, and Microalbuminuria in Patients with Type 2 Diabetes and Chronic Kidney Disease

Abstract

Objective: To evaluate the relationship of vitamin D status and vitamin D replacement therapy with glycemic control, serum uric acid (SUA) levels, and microalbuminuria (MAU) in patients with type 2 diabetes (T2DM) and chronic kidney disease (CKD). Subjectsand Methods: A total of 1,463 patients with T2DM and CKD (aged 14-88 years), 927 females and 536 males, were included in this study. The serum data of 25-hydroxyvitamin D, i.e., 25(OH)D, level, SUA, hemoglobin (Hb)A1_c, creatinine, estimated glomerular filtration rate, and urine albumin-to-creatinine ratio (UACR) were obtained from the medical records. The Mann-Whitney U test, the χ² test, the Mantel-Haenszel test, and linear regression models were used for data analysis. Results: Vitamin D deficiency and insufficiency were evident in 770 (52.0%) and 357 (24.0%) patients, respectively. Median HbA1_c levels (7.3 [IQR 3.9] vs. 6.5 [IQR 2.3]%; p < 0.01) were significantly higher in patients deficient in vitamin D than in those with a normal vitamin D status. A significantly low level of vitamin D was noted with a high UACR (β −0.01; 95% CI −0.01 to −0.001; p = 0.017) and HbA1_c (β −1.1; 95% CI −1.6 to −0.6; p < 0.001), but with low levels of SUA (β 1.3; 95% CI 0.5-2.2; p = 0.002). Vitamin D replacement was associated with a significantly low level of HbA1_c (7.4 [2.7] vs. 6.7 [1.9]%; p < 0.001]. Conclusion: In this study, there was a high prevalence of hypovitaminosis D among T2DM patients with CKD, with a higher UACR, higher HbA1_c, and lower SUA being noted as playing a role in predicting a decrease in vitamin D levels and potential benefits of vitamin D replacement therapy on glycemic control in T2DM management.

Urinary Uromodulin/Creatinine Ratio as a Potential Clinical Biomarker for Chronic Kidney Disease Patients with Gout: A Pilot Study

“…Most studies have documented that elevated serum uric acid independently predicts the development of CKD [10-13]. Mild hyperuricemia, induced in normal rats by the uricase inhibitor (oxonic acid), induced oxidative stress and endothelial dysfunction, resulting in the development of both systemic and glomerular hypertension in association with elevated renal vascular resistance, reduced renal blood flow, and led to the development of arteriolosclerosis, glomerular injury, and tubulointerstitial fibrosis [14-16].…”

Effects of vitamin D on the renin-angiotensin system

“…Studies by Sipahi (2017) show that vitamin D is involved in the absorption of calcium and phosphorus in the small intestine, and under its action a specific protein is formed on the surface of the small intestinal mucosa, known as calcium binding protein, responsible for calcium binding and transport via active transport through the walls of the small intestine (24).…”

“…There is evidence from studies by Sipahi (2017) and Atalay (2017) that in the kidneys vitamin D affects the phosphate ion reabsorption, increasing it and increasing its blood concentration (hyperphosphatemia) in the course of phosphorous exchange, and this effect is also opposed to the parathormone effect (24,25).…”

“…Sibuh (2018) points out that in experiments with rats subjected to high fructose diet, a significant improvement in serum glucose and lipid profile after vitamin D supplementation was observed and described. Supplementation was associated with protective properties in terms of developing dyslipidemia and hyperglycemia (23,24,(27)(28)(29). Li (2003) suggests that the spectrum of physiological effects of vitamin D goes beyond its role as one of the factors involved in the regulation of calcium-phosphorus homeostasis and bone metabolism.…”

The Relationship between Vitamin D and Type 2 Diabetes Is Intriguing: Glimpses from the Spect-China Study

“…The relationship between vitamin D deficiency and T2DM has been studied in some epidemiological studies [12,13]. A cross-section study has reported that 25(OH)D was significantly decreased in group T2DM compared to the control group [14].…”