Free - but not total - vitamin D serum concentrations in diabetes patients with impaired kidney function are inversely associated with systolic blood pressure (SBP).
Germany: Free vitamin D measurements as compared to total vitamin D measurements may be more clinically relevant to adjust vitamin D therapy in diabetes patients with impaired kidney function, suggests a recent study. The study results were published in the journal Clinical Nephrology.
Vitamin D is associated with blood pressure (BP) regulation. Shufei Zeng, Fifth Department of Medicine, University Medical Center Mannheim, University of Heidelberg, Heidelberg, Germany, and colleagues aimed to compare the association of BP in diabetic patients with either total vitamin D (standard way of analyzing the vitamin D status) or free vitamin D in an analytical cross-sectional study. This is because only free vitamin D passes the cell membrane and interacts with the nuclear vitamin D receptor (VDR).
The study was conducted with 178 diabetic patients with impaired kidney function. The researchers measured free and total vitamin D concentrations in all patients.
Multiple linear regression analysis considering patient age, sex, body mass index, height, smoking and drinking situation, the use of antihypertensive drugs, cholecalciferol treatment, C-reactive protein and estimated glomerular filtration rate as confounding factors were conducted to compare the association of free and total vitamin D with systolic and diastolic blood pressure (SBP and DBP).
Based on the study, the researchers found the following:
Multiple linear regression analysis revealed that neither SBP nor DBP was correlated with total vitamin D.
However, the concentration of free vitamin D was independently associated with SBP, but not with DBP.
In conclusion, free – but not total – vitamin D serum concentrations in patients with diabetes and impaired kidney function are inversely correlated with SBP.
"Our study suggests that free vitamin D measurements might be more clinically relevant – as compared to measurements of total vitamin D – to adjust vitamin D therapy in diabetic patients with impaired kidney function," wrote the authors.
Reference:
Shufei Zeng, Daniela Bachert, Mira Pavkovic, Peter Sandner, Carl-Friedrich Hocher, Oleg Tsuprykov, Stanislao Morgera, Bernhard Karl Krämer, Berthold Hocher, and Saban Elitok.Free vitamin D is independently associated with systolic blood pressure in diabetic patients with impaired kidney function . ; : 0-6. doi: 10.5414/CN110549.