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.
Tomaschitz
Andreas
A
Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Austria. andreas.tomaschitz@gmx.at
Pilz
Stefan
S
Ritz
Eberhard
E
Grammer
Tanja
T
Drechsler
Christiane
C
Boehm
Bernhard O
BO
März
Winfried
W
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