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A randomized controlled trial of the effects of vitamin D supplementation on arterial stiffness and aortic blood pressure in Native American women.

ABSTRACT: It is unclear if vitamin D supplementation improves central blood pressure or arterial stiffness in Native American (NA) women.Healthy postmenopausal NA women were randomized to receive 400 IU or 2500 IU of vitamin D for 6 months. Central systolic blood pressure (cSBP), central pulse pressure (cPP) and aortic augmentation index (AIx) were estimated by tonometry at baseline and after 6 months.Study volunteers (n = 98) were 61 (7.3) years old. 25(OH)D was 26.4 (11.0) ng/mL. 25(OH)D was similar between the two treatment groups (p = 0.291), as were baseline cSBP, cPP, and CVD risk factors (all p > 0.1). Treatment with 2500 IU of daily vitamin D3 did not affect cSBP, cPP, or AIx (all p > 0.1) compared to 400 IU daily.Despite low serum 25(OH)D at baseline, 6 months of vitamin D supplementation did not improve central blood pressure parameters or arterial stiffness in NA women. CLINICAL TRIALS.NCT01490333.

SUBMITTER: Gepner AD

PROVIDER: S-EPMC4441558 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature

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A randomized controlled trial of the effects of vitamin D supplementation on arterial stiffness and aortic blood pressure in Native American women.

Gepner Adam D AD Haller Irina V IV Krueger Diane C DC Korcarz Claudia E CE Binkley Neil N Stein James H JH

Atherosclerosis 20150425 2

<h4>Objective</h4>It is unclear if vitamin D supplementation improves central blood pressure or arterial stiffness in Native American (NA) women.<h4>Methods</h4>Healthy postmenopausal NA women were randomized to receive 400 IU or 2500 IU of vitamin D for 6 months. Central systolic blood pressure (cSBP), central pulse pressure (cPP) and aortic augmentation index (AIx) were estimated by tonometry at baseline and after 6 months.<h4>Results</h4>Study volunteers (n = 98) were 61 (7.3) years old. 25(O ...[more]

PMID: 25955191

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Project description:Systolic BP and large elastic artery stiffness both increase with age and are reduced by dietary sodium restriction. Production of the natriuretic hormone marinobufagenin, an endogenous ?1 Na+,K+-ATPase inhibitor, is increased in salt-sensitive hypertension and contributes to the rise in systolic BP during sodium loading.The hypothesis was that dietary sodium restriction performed in middle-aged/older adults (eight men and three women; 60 ± 2 years) with moderately elevated systolic BP (139 ± 2/83 ± 2 mmHg) would reduce urinary marinobufagenin excretion as well as systolic BP and aortic pulse-wave velocity (randomized, placebo-controlled, and crossover design). This study also explored the associations among marinobufagenin excretion with systolic BP and aortic pulse-wave velocity across conditions of 5 weeks of a low-sodium (77 ± 9 mmol/d) and 5 weeks of a normal-sodium (144 ± 7 mmol/d) diet.Urinary marinobufagenin excretion (weekly measurements; 25.4 ± 1.8 versus 30.7 ± 2.1 pmol/kg per day), systolic BP (127 ± 3 versus 138 ± 5 mmHg), and aortic pulse-wave velocity (700 ± 40 versus 843 ± 36 cm/s) were lower during the low- versus normal-sodium condition (all P<0.05). Across all weeks, marinobufagenin excretion was related with systolic BP (slope=0.61, P<0.001) and sodium excretion (slope=0.46, P<0.001). These associations persisted during the normal- but not the low-sodium condition (both P<0.005). Marinobufagenin excretion also was associated with aortic pulse-wave velocity (slope=0.70, P=0.02) and endothelial cell expression of NAD(P)H oxidase-p47phox (slope=0.64, P=0.006).These results show, for the first time in humans, that dietary sodium restriction reduces urinary marinobufagenin excretion and that urinary marinobufagenin excretion is positively associated with systolic BP, aortic stiffness (aortic pulse-wave velocity), and endothelial cell expression of the oxidant enzyme NAD(P)H oxidase. Importantly, marinobufagenin excretion is positively related to systolic BP over ranges of sodium intake typical of an American diet, extending previous observations in rodents and humans fed experimentally high-sodium diets.

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A randomized controlled trial of the effects of vitamin D supplementation on arterial stiffness and aortic blood pressure in Native American women.

Publications

A randomized controlled trial of the effects of vitamin D supplementation on arterial stiffness and aortic blood pressure in Native American women.

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