Independent association between 1,25-dihydroxyvitamin D, 25-hydroxyvitamin D and the renin-angiotensin system: The Ludwigshafen Risk and Cardiovascular Health (LURIC) study.
BACKGROUND
Antihypertensive and tissue-protective properties of vitamin D metabolites are increasingly attributed to the inhibition of renin synthesis by 1,25-dihydroxyvitamin D [1,25(OH)2D] in the kidney.


METHODS
We aimed to document a potential association between 25-hydroxyvitamin D [25(OH)D], 1,25(OH)2D and the circulating renin-angiotensin system (RAS) in a large cohort of patients referred (n=3316) to coronary angiography.


RESULTS
Of the 3316 subjects, 3296 (median age: 63.5 (56.3-70.6)years; 30.2% women) had a baseline measurement of 25(OH)D [median: 15.6(10.1-23.0)microg/L)], 1,25(OH)2D [median: 33.2(25.2-42.9)pg/mL], plasma renin concentration [PRC; median: 11.4(6.0-24.6)pg/mL] and angiotensin 2 [median: 20.0(12.0-35.0)ng/L]. Multivariate adjusted ANCOVA showed a steady increase of PRC values across declining deciles of 25(OH)D and 1,25(OH)2D values (P=0.013 and P=0.045), respectively. Additionally, mean angiotensin 2 values increased significantly across decreasing 25(OH)D and 1,25(OH)2D values (P=0.020 and P=0.024, respectively). In contrast, multivariate adjusted ANCOVA revealed no significant associations between aldosterone, aldosterone-to-renin ratio and 25(OH)D/1,25(OH)2D values. In multivariate stepwise regression analyses both, 25(OH)D and 1,25(OH)2D emerged as independent predictors of plasma renin and angiotensin 2 concentrations.


CONCLUSIONS
Our data showed for the first time in humans that both, lower 25(OH)D and 1,25(OH)2D values are independently related to an upregulated circulating RAS.
Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Austria. andreas.tomaschitz@gmx.at
Andreas
A
Tomaschitz
Stefan
S
Pilz
Eberhard
E
Ritz
Tanja
T
Grammer
Christiane
C
Drechsler
Bernhard O
BO
Boehm
Winfried
W
März
D000368:Aged; D000704:Analysis of Variance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012084:Renin-Angiotensin System; D012307:Risk Factors; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
D014807:Vitamin D; C097949:1,25-dihydroxyvitamin D; C104450:25-hydroxyvitamin D