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Abstract
Purpose of the Review Results from epidemiological studies suggest that vitamin D (VD) deficiency (VDD) may be a cause of hypertension (HTN). However, the results of randomized clinical trials (RCTs) designed to address the impact of VD supplementation on reducing blood pressure (BP) remain equivocal. To determine whether VD might serve as a beneficial treatment option for a specific subset of hypertensive patients, we performed a stratified analysis of RCT data and addressed problems associated with some methodological issues. Recent Findings HTN is caused by multiple factors. VDD may be one of the factors contributing to the development of this disorder. There are more than 70 RCTs that examined the impact of VD supplementation on BP. These RCTs can be classified into four groups based on their respective study populations, including participants who are (1) VD-sufficient and normotensive, (2) VD-deficient and normotensive, (3) VD-sufficient and hypertensive, and (4) VD-deficient and hypertensive. Summary Our evaluation of these studies demonstrates that VD supplementation is ineffective when used to reduce BP in VD-sufficient normotensive subjects. VD supplementation for five years or more may reduce the risk of developing HTN specifically among those with VDD. Interestingly, findings from 12 RCTs indicate that daily or weekly supplementation, as opposed to large bolus dosing, results in the reduction of BP in VD-deficient hypertensive patients. Our ongoing research focused on elucidating the mechanisms of VDD-induced HTN will ultimately provide evidence to support the development of etiology-specific prevention and treatment strategies focused on HTN in the VD-deficient population.
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2
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Doneray H, Akbulut OZ, Ozden A, Yildirim A, Orbak Z. Plasma renin, aldosterone, and urinary prostaglandin E 2 levels in children with hypocalcemia due to vitamin D deficiency rickets. Prostaglandins Other Lipid Mediat 2022; 162:106652. [PMID: 35688409 DOI: 10.1016/j.prostaglandins.2022.106652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/30/2022] [Accepted: 06/02/2022] [Indexed: 11/16/2022]
Abstract
We investigated the effect of hypocalcemia on plasma renin, aldosterone, and urine PGE2 levels in children with vitamin D deficiency rickets (VDDR). In the study group, 25 patients with VDDR-induced hypocalcemia were treated with a single dose of 150,000-300,000 IU cholecalciferol and 50 mg/kg/day elemental Ca for 10 days. On any day between 21th and 30th days after the treatment, the patients' clinical, biochemical and radiologic findings were re-evaluated. The healthy children with the same sex and similar age as the study group comprised the control group. Plasma sodium (Na), potassium (K), calcium (Ca), phosphorus (P), alkaline phosphatase (ALP), parathyroid hormone (PTH), 25- hydroxy vitamin D (25OHD), renin, aldosterone; and urinary Ca, creatinine (Cr) and prostaglandin E2 (PGE2) levels were measured in both the study (pre-treatment and post-treatment) and the control group. Plasma Ca, P, 25OHD and renin levels and urinary PGE2/Cr ratio in the post-treatment group were significantly higher than those in the pre-treatment group while K, ALP, and PTH concentrations were significantly lower. Plasma ALP and PTH levels in pre-treatment group were significantly higher than in the control group while Ca, P, 25OHD, aldosterone and renin concentrations and urinary PGE2/Cr ratio were significantly lower. Post-treatment plasma Ca level was significantly decreased in normal limits compared to the control group while other biochemical parameters were not different from the control group. Plasma Ca concentration was positively correlated with renin level and urinary PGE2/Cr ratio. The findings suggest that hypocalcemia may inhibit the production of renin, aldosterone and PGE2 and a blunt aldosterone secretion may develop even after recovery from hypocalcemia.
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Affiliation(s)
- Hakan Doneray
- Department of Pediatric Endocrinology, Faculty of Medicine, Ataturk University, Erzurum, Turkey; Clinical Research Development and Design Application and Research Center, Ataturk University, Erzurum, Turkey.
| | | | - Ayse Ozden
- Department of Pediatric Endocrinology, Erzurum Regional Training & Research Hospital, Erzurum, Turkey
| | - Abdulkadir Yildirim
- Department of Biochemistry, Faculty of Medicine, Ataturk University, Erzurum, Turkey
| | - Zerrin Orbak
- Department of Pediatric Endocrinology, Faculty of Medicine, Ataturk University, Erzurum, Turkey
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3
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Tiosano D, Abrams SA, Weisman Y. Lessons Learned from Hereditary 1,25-Dihydroxyvitamin D-Resistant Rickets Patients on Vitamin D Functions. J Nutr 2021; 151:473-481. [PMID: 33438017 DOI: 10.1093/jn/nxaa380] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/25/2020] [Accepted: 11/04/2020] [Indexed: 01/08/2023] Open
Abstract
We summarize here lessons learned from studies on skeletal and extra-skeletal functions of vitamin D in hereditary 1,25-dihydroxyvitamin D-resistant rickets (HVDRR) patients with a mutant, nonfunctioning vitamin D receptor (VDR). During childhood, HVDRR patients are dependent on intestinal VDR, demonstrate low intestinal fraction calcium absorption, and have a bone calcium accretion rate that leads to hypocalcemia and rickets. After puberty, there is recovery in intestinal calcium absorption and in bone calcium accretion and structure. HVDRR monocytes and lymphocytes show impairment in the expression of antimicrobial proteins and demonstrate a proinflammatory cytokine profile. However, HVDRR patients do not exhibit increased rates of infections or inflammatory diseases. Vitamin D deficiency is associated with asthmatic exacerbations. Surprisingly, HVDRR patients do not usually develop asthma. They have normal allergic tests and lung functions and are protected against provoked bronchial hyperactivity. HVDRR patients have decreased IL-5 levels in their exhaled breath condensate. Given that IL-5 is a key cytokine in the development of airway inflammation and hyperactivity and that VDR is important for IL-5 generation, it is plausible that low lung IL-5 protects HVDRR patients from asthma. Vitamin D metabolites have suppressive effects on the renin angiotensin system. However, no HVDRR patient showed hypertension or echocardiographic pathology, and their renin angiotensin metabolites were normal. The VDR is expressed throughout the reproductive system, suggesting a role in reproduction. However, the reproductive history of HVDRR patients is normal despite the lack of a normal VDR. HVDRR patients provide a unique opportunity to study the role of the VDR and the role of vitamin D in various human systems.
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Affiliation(s)
- Dov Tiosano
- Pediatric Endocrinology Unit, Ruth Rappaport Children's Hospital, Rambam Healthcare Campus, Haifa, Israel
| | - Steven A Abrams
- Department of Pediatrics, Dell Medical School at the University of Texas-Austin, Austin, TX, USA
| | - Yoseph Weisman
- Department of Pediatrics, Dana-Dwek Children's Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
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4
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Suessenbach FK, Burckhardt BB. Levels of angiotensin peptides in healthy and cardiovascular/renal-diseased paediatric population-an investigative review. Heart Fail Rev 2020; 24:709-723. [PMID: 31104255 DOI: 10.1007/s10741-019-09797-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The renin-angiotensin-aldosterone system (RAAS) plays a major role in the regulation of blood pressure and homeostasis. Therefore, it is a commonly used target for pharmacotherapy of cardiovascular diseases in adults. However, the efficacy of this pharmacotherapy can only be limitedly derived into children. Comprehensive knowledge of the humoral parameters acting in the paediatric RAAS (e.g. angiotensin I, angiotensin II, angiotensin 1-7, angiotensin III, and angiotensin IV) might facilitate a more effective and rational pharmacotherapy in children. Therefore, this review aims to provide an overview of the maturing RAAS. Out of 925 identified records, 35 publications were classified as relevant. Physiological and pathophysiological concentrations of angiotensin peptides were compiled and categorised according to European Medicines Agency age groups. Age has a major impact on circulating angiotensin I, angiotensin II, and angiotensin 1-7, which is reflected in an age-dependent decrease during childhood. In contrast to data obtained in adults, no gender-related differences in angiotensin levels were identified. The observed increase in peptide concentrations regarding cardiac- and renal-diseased children is influenced by surgical repair, while evidence for a pharmacological impact is conflicting. A comprehensive set of angiotensin I, angiotensin II, and angiotensin 1-7 values from neonates up to adolescents was compiled. Indicating age as a strong effector. However, evidence about potential promising targets of the RAAS like angiotensin III and angiotensin IV is still lacking in children.
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Affiliation(s)
- F K Suessenbach
- Institute of Clinical Pharmacy and Pharmacotherapy, Heinrich Heine University, Universitaetsstr. 1, 40225, Dusseldorf, Germany
| | - B B Burckhardt
- Institute of Clinical Pharmacy and Pharmacotherapy, Heinrich Heine University, Universitaetsstr. 1, 40225, Dusseldorf, Germany.
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5
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Investigating the association of vitamin D with blood pressure and the renin–angiotensin–aldosterone system in hypertensive subjects: a cross-sectional prospective study. J Hum Hypertens 2017; 32:114-121. [DOI: 10.1038/s41371-017-0005-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 08/17/2017] [Accepted: 08/29/2017] [Indexed: 11/08/2022]
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Afzal S, Nordestgaard BG. Vitamin D, Hypertension, and Ischemic Stroke in 116 655 Individuals From the General Population: A Genetic Study. Hypertension 2017; 70:HYPERTENSIONAHA.117.09411. [PMID: 28760944 DOI: 10.1161/hypertensionaha.117.09411] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Revised: 04/11/2017] [Accepted: 06/19/2017] [Indexed: 01/01/2023]
Abstract
Observational studies indicate that low concentrations of plasma 25-hydroxyvitamin D (25(OH)D) are associated with high blood pressure, hypertension, and ischemic stroke. However, whether these associations are causal remain unknown. A total of 116 655 white individuals of Danish descent from the general population were genotyped for genetic variants in DHCR7 and CYP2R1 affecting plasma 25(OH)D concentrations; 35 517 had plasma 25(OH)D measurements. Primary outcomes were blood pressure, hypertension, and ischemic stroke. Median follow-up for incident ischemic stroke was 9.3 years (range, 1 day-33.6 years). DHCR7/CYP2R1 allele score was as expected associated with lower 25(OH)D concentration (F=328 and R2=1.0%). A genetically determined 10 nmol/L lower 25(OH)D concentration was associated with a 0.68 (95% confidence interval [CI], 0.20-1.17) mm Hg higher systolic blood pressure and a 0.36 (95% CI, 0.08-0.63) mm Hg higher diastolic blood pressure with corresponding observational estimates of 0.58 (95% CI, 0.50-0.68) and 0.40 (95% CI, 0.35-0.45) mm Hg. The odds ratio for hypertension was 1.02 (95% CI, 0.97-1.08) for a genetically determined 10 nmol/L lower 25(OH)D with a corresponding observational odds ratio of 1.06 (95% CI, 1.05-1.07). The odds ratio for ischemic stroke was 0.98 (95% CI, 0.86-1.13) for a genetically determined 10 nmol/L decrease in 25(OH)D with a corresponding observational odds ratio of 1.03 (95% CI, 1.01-1.05). Genetic and observational low 25(OH)D concentrations were associated with higher blood pressure, as well as with hypertension consistent with causal relationships. Because observational but not genetic low 25(OH)D concentration was associated with ischemic stroke, and as the CIs overlapped, we can neither support nor exclude a causal relationship.
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Affiliation(s)
- Shoaib Afzal
- From the Department of Clinical Biochemistry and the Copenhagen General Population Study, Herlev and Gentofte Hospital (S.A., B.G.N.) and the Copenhagen City Heart Study, Frederiksberg Hospital (B.G.N.), Copenhagen University Hospital, Herlev, Denmark; and Faculty of Health and Medical Sciences, University of Copenhagen, Denmark (S.A., B.G.N.)
| | - Børge G Nordestgaard
- From the Department of Clinical Biochemistry and the Copenhagen General Population Study, Herlev and Gentofte Hospital (S.A., B.G.N.) and the Copenhagen City Heart Study, Frederiksberg Hospital (B.G.N.), Copenhagen University Hospital, Herlev, Denmark; and Faculty of Health and Medical Sciences, University of Copenhagen, Denmark (S.A., B.G.N.).
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7
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Kinoshita Y, Ito N, Makita N, Nangaku M, Fukumoto S. Changes in bone metabolic parameters following oral calcium supplementation in an adult patient with vitamin D-dependent rickets type 2A. Endocr J 2017; 64:589-596. [PMID: 28367941 DOI: 10.1507/endocrj.ej16-0583] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Vitamin D-dependent rickets type 2A (VDDR2A) is a rare inherited disorder with decreased tissue responsiveness to 1,25-dihydroxyvitamin D [1,25(OH)2D], caused by loss of function mutations in the vitamin D receptor (VDR) gene. Approximately 50 types of mutations have been identified so far that change amino acids in either the N-terminal DNA binding domain (DBD) or the C-terminal ligand binding domain (LBD) of the VDR protein. The degree of responsiveness to 1,25(OH)2D varies between patients with VDDR2A, which may depend on their residual VDR function. In this report, we describe a female patient with VDDR2A caused by an early stop codon (R30X) in the VDR gene that resulted in a severely truncated VDR protein. She developed alopecia and bowed legs within a year after birth and was diagnosed with rickets at the age of 2. She had been treated with active vitamin D and oral calcium supplementation until 22 years of age, when she developed secondary hyperparathyroidism and high bone turnover. The genetic diagnosis of VDDR2A promoted the discontinuation of active vitamin D treatment in favor of monotherapy with oral calcium supplementation. We observed amelioration of the secondary hyperparathyroidism and normalization of bone metabolic parameters within 6 years.
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Affiliation(s)
- Yuka Kinoshita
- Division of Nephrology & Endocrinology, Department of Medicine, the University of Tokyo Hospital, Tokyo, Japan
| | - Nobuaki Ito
- Division of Nephrology & Endocrinology, Department of Medicine, the University of Tokyo Hospital, Tokyo, Japan
| | - Noriko Makita
- Division of Nephrology & Endocrinology, Department of Medicine, the University of Tokyo Hospital, Tokyo, Japan
| | - Masaomi Nangaku
- Division of Nephrology & Endocrinology, Department of Medicine, the University of Tokyo Hospital, Tokyo, Japan
| | - Seiji Fukumoto
- Fujii Memorial Institute of Medical Sciences, Tokushima University, Tokushima, Japan
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Grübler MR, März W, Pilz S, Grammer TB, Trummer C, Müllner C, Schwetz V, Pandis M, Verheyen N, Tomaschitz A, Fiordelisi A, Laudisio D, Cipolletta E, Iaccarino G. Vitamin-D concentrations, cardiovascular risk and events - a review of epidemiological evidence. Rev Endocr Metab Disord 2017; 18:259-272. [PMID: 28451877 DOI: 10.1007/s11154-017-9417-0] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Vitamin D has long been established as an elemental factor of bone physiology. Beyond mineral metabolism, the expression of the vitamin D receptor has been identified throughout the cardiovascular (CV) system. Experimental studies showed beneficial effects of vitamin D on heart and vessels, but vitamin D intoxication in animals also led to hypercalcemia and vascular calcification. Our knowledge has been extended by epidemiological studies that showed that 25-hydroxyvitamin D (25(OH)D) levels are inversely associated with an increased CV risk itself, but also with established CV risk factors, such as arterial hypertension, endothelial dysfunction and atherosclerosis. Conversely, randomized controlled trials could not document significant and consistent effects of vitamin D supplementation on CV risk or events. Potential explanations may lie in differences in reference ranges or the possibility that low vitamin D in CV disease is only an epiphenomenon. In the latter case, the key question is why low 25(OH)D levels are such a strong predictor of health. While we wait for new data, the current conclusion is that vitamin D is a strong risk marker for CV risk factors and for CV diseases itself.
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Affiliation(s)
- Martin Robert Grübler
- Swiss Cardiovascular Centre Bern, Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse 8, 3010, Bern, Switzerland.
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, Graz, Austria.
| | - Winfried März
- Vth Department of Medicine (Nephrology, Hypertensiology, Endocrinology, Diabetology, and Rheumatology), Mannheim Medical Faculty, University of Heidelberg, Mannheim, Germany
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
- Synlab Academy, Synlab Services GmbH, and Augsburg, Mannheim, Germany
| | - Stefan Pilz
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, Graz, Austria
- Department of Epidemiology and Biostatistics, EMGO Institute for Health and Care Research, VU University Medical Centre, Amsterdam, Netherlands
| | - Tanja B Grammer
- Mannheim Institute of Public Health, Mannheim Medical Faculty, University of Heidelberg, Mannheim, Germany
| | - Christian Trummer
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, Graz, Austria
| | - Christian Müllner
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, Graz, Austria
| | - Verena Schwetz
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, Graz, Austria
| | - Marlene Pandis
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, Graz, Austria
| | - Nicolas Verheyen
- Department of Internal Medicine, Division of Cardiology, Medical University of Graz, Graz, Austria
| | - Andreas Tomaschitz
- Department of Internal Medicine, Division of Cardiology, Medical University of Graz, Graz, Austria
- Bad Gleichenberg Clinic, Schweizereiweg 4, 8344, Bad Gleichenberg, Austria
| | | | | | - Ersilia Cipolletta
- Department of Medicine, Surgery Odontoiatrics-Scuola Medica Salernitana, University of Salerno, Salerno, Italy
| | - Guido Iaccarino
- Department of Medicine, Surgery Odontoiatrics-Scuola Medica Salernitana, University of Salerno, Salerno, Italy
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Cuervo C, Abitbol CL, Zilleruelo GE, Freundlich M. Fibroblast growth factor-23 and renin-angiotensin system levels in vitamin-D-dependent rickets type I. Pediatr Nephrol 2016; 31:1189-93. [PMID: 26939683 DOI: 10.1007/s00467-016-3356-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Revised: 02/12/2016] [Accepted: 02/13/2016] [Indexed: 12/20/2022]
Abstract
BACKGROUND As 1,25(OH)2D3 vitamin D3 induces fibroblast growth factor-23 (FGF-23) production and suppresses the renin-angiotensin-aldosterone system (RAAS), its absence in vitamin-D-dependent rickets type I (VDDR-I) may have adverse health consequences. CASE DESCRIPTION An infant presented at age 8 months with hypocalcemia and rickets and very low 1,25(OH)2D3 levels. Genetic analysis confirmed VDRR-I, and calcitriol therapy was initiated. During periods of nonadherence to therapy, chemical measurements revealed detectable FGF-23 levels, with undetectable 1,25(OH)2D3, hypophosphatemia, low tubular reabsorption of phosphate, hypocalcemia, and very elevated parathyroid hormone (PTH) levels. These changes, in addition to elevated RAAS levels, normalized during calcitriol therapy despite elevated FGF-23 levels. At age 12 years, all rachitic manifestations were absent, and bone mineral density (BMD) and the echocardiogram were normal. CONCLUSIONS Whereas 1,25(OH)2D3 is not indispensable for FGF-23 production, PTH in the absence of vitamin D may maintain FGF-23 secretion despite hypocalcemia. Normalization of urinary phosphate losses despite elevated FGF-23 during calcitriol-mediated suppression of secondary hyperparathyroidism points to a cardinal role of PTH as a cause of the phosphaturia in VDRR-I. Normalization of RAAS by calcitriol may conceivably prevent adverse cardiovascular outcomes.
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Affiliation(s)
- Carlos Cuervo
- Division of Pediatric Nephrology, University of Miami Miller School of Medicine, PO Box 016960(M-714), Miami, FL, 33101, USA
| | - Carolyn L Abitbol
- Division of Pediatric Nephrology, University of Miami Miller School of Medicine, PO Box 016960(M-714), Miami, FL, 33101, USA
| | - Gaston E Zilleruelo
- Division of Pediatric Nephrology, University of Miami Miller School of Medicine, PO Box 016960(M-714), Miami, FL, 33101, USA
| | - Michael Freundlich
- Division of Pediatric Nephrology, University of Miami Miller School of Medicine, PO Box 016960(M-714), Miami, FL, 33101, USA.
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10
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Abstract
Vitamin D is a precursor of the steroid hormone calcitriol that is crucial for bone and mineral metabolism. Both the high prevalence of vitamin D deficiency in the general population and the identification of the vitamin D receptor in the heart and blood vessels raised interest in the potential cardiovascular effects of vitamin D. Experimental studies have demonstrated various cardiovascular protective actions of vitamin D, but vitamin D intoxication in animals is known to induce vascular calcification. In meta-analyses of epidemiological studies, vitamin D deficiency is associated with an increased cardiovascular risk. Findings from Mendelian randomization studies and randomized, controlled trials (RCTs) do not indicate significant effects of a general vitamin D supplementation on cardiovascular outcomes. Previous RCTs, however, were not adequately designed to address extraskeletal events, and did not focus on vitamin D-deficient individuals. Therefore, currently available evidence does not support cardiovascular benefits or harms of vitamin D supplementation with the commonly used doses, and whether vitamin D has cardiovascular effects in individuals with overt vitamin D deficiency remains to be evaluated. Here, we provide an update on clinical studies on vitamin D and cardiovascular risk, discuss ongoing vitamin D research, and consider the management of vitamin D deficiency from a cardiovascular health perspective.
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11
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Abstract
The classical clinical consequence of vitamin D deficiency is osteomalacia, presenting as rickets in children. This remains a common problem in parts of the Middle East and the Indian subcontinent, and occurs when serum 25-hydroxyvitamin D levels are <25 nmol/L. Osteomalacia remains the only problem that is unequivocally a consequence of vitamin D deficiency. Low levels of 25-hydroxyvitamin D are observed in a wide range of conditions, but consistent trial evidence of amelioration of these conditions with vitamin D is lacking. Monotherapy with vitamin D has not been found to be effective in meta-analyses of trials assessing its effects on bone density, fractures or falls. At present, supplements should be advised for individuals at risk of having serum 25-hydroxyvitamin D levels in the 25-40 nmol/L range, or below, with a view to prevention of osteomalacia.
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Affiliation(s)
- Ian R Reid
- University of Auckland, Auckland, New Zealand Department of Endocrinology, Auckland District Health Board, Auckland, New Zealand
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12
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Ersoy B, Kiremitci S, Isojima T, Kitanaka S. Successful intermittent intravenous calcium treatment via the peripheral route in a patient with hereditary vitamin D-resistant rickets and alopecia. Horm Res Paediatr 2015; 83:67-72. [PMID: 25573344 DOI: 10.1159/000367711] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 08/18/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Hereditary vitamin D-resistant rickets (HVDRR) is a rare genetic disorder caused by mutations in the vitamin D receptor (VDR) gene, which result in end-organ resistance to 1,25-(OH)2D3. PATIENTs with HVDRR are mostly treated using i.v. calcium therapy with a central catheter. However, central catheter-related complications have been reported. PATIENT The patient was a 3-year-old boy presenting with waddling gait and alopecia. He had hypocalcemia [8 mg/dl (2 mmol/l)], hyperparathyroidism (1,232 ng/l), and elevated 1,25-(OH)2D3 levels (>250 pmol/l). DNA sequence analyses of the VDR gene showed a homozygous C-T transition at codon 152, resulting in a non-sense mutation in exon 5. INTERVENTIONS AND OUTCOMES The patient was initially treated with calcitriol (80 ng/kg/day) and high-dose oral calcium (150 mg/kg/day) for one year. At the end of the first year, intermittent (5 days per month) i.v. calcium therapy without a central catheter was initiated because of insufficient clinical and radiological improvement. After 2 years of intermittent i.v. calcium therapy, there was a clear improvement based on clinical progress and on X-ray and biochemical findings. No peripheral complications were reported either. CONCLUSION HVDRR with a non-sense mutation in the ligand-binding domain and alopecia was successfully treated with intermittent i.v. calcium without a central catheter.
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Affiliation(s)
- Betul Ersoy
- Division of Pediatric Endocrinology and Metabolism, Celal Bayar University, School of Medicine, Manisa, Turkey
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13
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Chen S, Sun Y, Agrawal DK. Vitamin D deficiency and essential hypertension. ACTA ACUST UNITED AC 2015; 9:885-901. [PMID: 26419755 DOI: 10.1016/j.jash.2015.08.009] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 07/14/2015] [Accepted: 08/11/2015] [Indexed: 12/19/2022]
Abstract
Essential hypertension (EH) results when the balance between vasoconstriction and vasodilation is shifted in favor of vasoconstriction. This balance is controlled by the interaction of genetic and epigenetic factors. When there is an unstable balance, vitamin D deficiency as an epigenetic factor triggers a shift to the side of vasoconstriction. In this article, we critically analyze clinical findings on the effect of vitamin D on blood pressure, combined with progress in molecular mechanisms. We find that vitamin D repletion exerts a clinically significant antihypertensive effect in vitamin D-deficient EH patients. Of note, a few trials reported no antihypertensive effect from vitamin D due to suboptimal study design. Short-term vitamin D supplementation has no effect on blood pressure in normotensive subjects. This could explain the mixed results and may provide a theoretical basis for future trials to identify beneficial effects of vitamin D in intervention for EH.
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Affiliation(s)
- Songcang Chen
- Center for Clinical & Translational Science and Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE, USA.
| | - Yingxian Sun
- Department of Cardiology, First Affiliated Hospital, China Medical University, Shenyang, People's Republic of China
| | - Devendra K Agrawal
- Center for Clinical & Translational Science and Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE, USA
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Vimaleswaran KS, Cavadino A, Berry DJ, Jorde R, Dieffenbach AK, Lu C, Alves AC, Heerspink HJL, Tikkanen E, Eriksson J, Wong A, Mangino M, Jablonski KA, Nolte IM, Houston DK, Ahluwalia TS, van der Most PJ, Pasko D, Zgaga L, Thiering E, Vitart V, Fraser RM, Huffman JE, de Boer RA, Schöttker B, Saum KU, McCarthy MI, Dupuis J, Herzig KH, Sebert S, Pouta A, Laitinen J, Kleber ME, Navis G, Lorentzon M, Jameson K, Arden N, Cooper JA, Acharya J, Hardy R, Raitakari O, Ripatti S, Billings LK, Lahti J, Osmond C, Penninx BW, Rejnmark L, Lohman KK, Paternoster L, Stolk RP, Hernandez DG, Byberg L, Hagström E, Melhus H, Ingelsson E, Mellström D, Ljunggren O, Tzoulaki I, McLachlan S, Theodoratou E, Tiesler CMT, Jula A, Navarro P, Wright AF, Polasek O, Wilson JF, Rudan I, Salomaa V, Heinrich J, Campbell H, Price JF, Karlsson M, Lind L, Michaëlsson K, Bandinelli S, Frayling TM, Hartman CA, Sørensen TIA, Kritchevsky SB, Langdahl BL, Eriksson JG, Florez JC, Spector TD, Lehtimäki T, Kuh D, Humphries SE, Cooper C, Ohlsson C, März W, de Borst MH, Kumari M, Kivimaki M, Wang TJ, Power C, Brenner H, Grimnes G, van der Harst P, Snieder H, Hingorani AD, Pilz S, Whittaker JC, Järvelin MR, Hyppönen E. Association of vitamin D status with arterial blood pressure and hypertension risk: a mendelian randomisation study. Lancet Diabetes Endocrinol 2014; 2:719-29. [PMID: 24974252 PMCID: PMC4582411 DOI: 10.1016/s2213-8587(14)70113-5] [Citation(s) in RCA: 257] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Low plasma 25-hydroxyvitamin D (25[OH]D) concentration is associated with high arterial blood pressure and hypertension risk, but whether this association is causal is unknown. We used a mendelian randomisation approach to test whether 25(OH)D concentration is causally associated with blood pressure and hypertension risk. METHODS In this mendelian randomisation study, we generated an allele score (25[OH]D synthesis score) based on variants of genes that affect 25(OH)D synthesis or substrate availability (CYP2R1 and DHCR7), which we used as a proxy for 25(OH)D concentration. We meta-analysed data for up to 108 173 individuals from 35 studies in the D-CarDia collaboration to investigate associations between the allele score and blood pressure measurements. We complemented these analyses with previously published summary statistics from the International Consortium on Blood Pressure (ICBP), the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium, and the Global Blood Pressure Genetics (Global BPGen) consortium. FINDINGS In phenotypic analyses (up to n=49 363), increased 25(OH)D concentration was associated with decreased systolic blood pressure (β per 10% increase, -0·12 mm Hg, 95% CI -0·20 to -0·04; p=0·003) and reduced odds of hypertension (odds ratio [OR] 0·98, 95% CI 0·97-0·99; p=0·0003), but not with decreased diastolic blood pressure (β per 10% increase, -0·02 mm Hg, -0·08 to 0·03; p=0·37). In meta-analyses in which we combined data from D-CarDia and the ICBP (n=146 581, after exclusion of overlapping studies), each 25(OH)D-increasing allele of the synthesis score was associated with a change of -0·10 mm Hg in systolic blood pressure (-0·21 to -0·0001; p=0·0498) and a change of -0·08 mm Hg in diastolic blood pressure (-0·15 to -0·02; p=0·01). When D-CarDia and consortia data for hypertension were meta-analysed together (n=142 255), the synthesis score was associated with a reduced odds of hypertension (OR per allele, 0·98, 0·96-0·99; p=0·001). In instrumental variable analysis, each 10% increase in genetically instrumented 25(OH)D concentration was associated with a change of -0·29 mm Hg in diastolic blood pressure (-0·52 to -0·07; p=0·01), a change of -0·37 mm Hg in systolic blood pressure (-0·73 to 0·003; p=0·052), and an 8·1% decreased odds of hypertension (OR 0·92, 0·87-0·97; p=0·002). INTERPRETATION Increased plasma concentrations of 25(OH)D might reduce the risk of hypertension. This finding warrants further investigation in an independent, similarly powered study. FUNDING British Heart Foundation, UK Medical Research Council, and Academy of Finland.
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Affiliation(s)
- Karani S Vimaleswaran
- Population, Policy and Practice, UCL Institute of Child Health, London, UK; Hugh Sinclair Unit of Human Nutrition, Department of Food & Nutritional Sciences, School of Chemistry, Food & Pharmacy, University of Reading, Reading, UK
| | - Alana Cavadino
- Population, Policy and Practice, UCL Institute of Child Health, London, UK
| | - Diane J Berry
- Population, Policy and Practice, UCL Institute of Child Health, London, UK
| | | | - Rolf Jorde
- Tromsø Endocrine Research Group, Department of Clinical Medicine, University of Tromsø, Tromsø, Norway
| | - Aida Karina Dieffenbach
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center, Heidelberg, Germany
| | - Chen Lu
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Alexessander Couto Alves
- Department of Epidemiology and Biostatistics, Imperial College London, London, UK; Institute of Health Sciences, University of Oulu, Oulu, Finland
| | - Hiddo J Lambers Heerspink
- Department of Clinical Pharmacology, University Medical Center, University of Groningen, Groningen, Netherlands
| | - Emmi Tikkanen
- Institute for Molecular Medicine Finland, Tukholmankatu, Finland; Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland; Hjelt Institute, University of Helsinki, Helsinki, Finland
| | - Joel Eriksson
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Andrew Wong
- MRC Unit for Lifelong Health and Ageing, University College London, London, UK
| | - Massimo Mangino
- Department of Twin Research & Genetic Epidemiology, King's College London, St Thomas' Campus, London, UK
| | - Kathleen A Jablonski
- Biostatistics Center, Department of Epidemiology and Biostatistics, School of Public Health, George Washington University, Rockville, MD, USA
| | - Ilja M Nolte
- Department of Epidemiology, University Medical Center, University of Groningen, Groningen, Netherlands
| | - Denise K Houston
- Gerontology and Geriatric Medicine, Department of Internal Medicine, and J Paul Sticht Center on Aging, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Tarunveer Singh Ahluwalia
- Metabolic Genetics, Novo Nordisk Foundation Centre for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Copenhagen Prospective Studies on Asthma in Childhood, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Danish Pediatric Asthma Center, Gentofte Hospital, Copenhagen, Denmark
| | - Peter J van der Most
- Department of Epidemiology, University Medical Center, University of Groningen, Groningen, Netherlands
| | - Dorota Pasko
- Genetics of Complex Traits, University of Exeter Medical School, Exeter, UK
| | - Lina Zgaga
- Centre for Population Health Sciences, University of Edinburgh, Edinburgh, UK; Department of Public Health and Primary Care, Trinity College Dublin, Dublin, Ireland
| | - Elisabeth Thiering
- Institute of Epidemiology I, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, Germany; Division of Metabolic Diseases and Nutritional Medicine, Ludwig Maximilian University of Munich, Dr von Hauner Children's Hospital, Munich, Germany
| | - Veronique Vitart
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Ross M Fraser
- Centre for Population Health Sciences, University of Edinburgh, Edinburgh, UK
| | - Jennifer E Huffman
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Rudolf A de Boer
- Department of Cardiology, University Medical Center, University of Groningen, Groningen, Netherlands
| | - Ben Schöttker
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center, Heidelberg, Germany
| | - Kai-Uwe Saum
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center, Heidelberg, Germany
| | - Mark I McCarthy
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK; Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK; Oxford NIHR Biomedical Research Centre, Oxford, UK
| | - Josée Dupuis
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA; National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
| | - Karl-Heinz Herzig
- Institute of Biomedicine, University of Oulu, Oulu, Finland; Biocenter Oulu, University of Oulu, Oulu, Finland; Medical Research Center Oulu, Oulu University Hospital, Oulu, Finland
| | - Sylvain Sebert
- Biocenter Oulu, University of Oulu, Oulu, Finland; Institute of Health Sciences, University of Oulu, Oulu, Finland
| | - Anneli Pouta
- Obstetrics and Gynecology, Department of Clinical Sciences, Oulu University Hospital, Oulu, Finland; National Institute for Health and Welfare, Oulu, Finland
| | - Jaana Laitinen
- Finnish Institute of Occupational Health, Helsinki, Finland
| | - Marcus E Kleber
- Medical Clinic V (Nephrology, Hypertensiology, Rheumatology, Endocrinology, Diabetology), Mannheim Medical Faculty, University of Heidelberg, Mannheim, Germany
| | - Gerjan Navis
- Department of Internal Medicine, Division of Nephrology, University Medical Center, University of Groningen, Groningen, Netherlands
| | - Mattias Lorentzon
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Karen Jameson
- MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK
| | - Nigel Arden
- NIHR Oxford Musculoskeletal Biomedical Research Unit, University of Oxford, Oxford, UK; MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK
| | - Jackie A Cooper
- Cardiovascular Genetics, BHF Laboratories, Institute of Cardiovascular Science, University College London, London, UK
| | - Jayshree Acharya
- Cardiovascular Genetics, BHF Laboratories, Institute of Cardiovascular Science, University College London, London, UK
| | - Rebecca Hardy
- MRC Unit for Lifelong Health and Ageing, University College London, London, UK
| | - Olli Raitakari
- Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, Turku, Finland; Department of Clinical Physiology and Nuclear Medicine, Turku University Hospital, Turku, Finland
| | - Samuli Ripatti
- Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland
| | - Liana K Billings
- Center for Human Genetic Research and Diabetes Research Center, Massachusetts General Hospital, Boston, MA, USA; Program in Medical and Population Genetics, Broad Institute, Cambridge, MA, USA; Department of Medicine, Harvard Medical School, Boston, MA, USA; NorthShore University HealthSystem, Evanston, IL, USA
| | - Jari Lahti
- Institute of Behavioural Sciences, University of Helsinki, Helsinki, Finland
| | - Clive Osmond
- MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK
| | - Brenda W Penninx
- Department of Psychiatry, EMGO Institute, VU University Medical Centre, Amsterdam, Netherlands
| | - Lars Rejnmark
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Kurt K Lohman
- Department of Biostatistical Sciences, Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Lavinia Paternoster
- MRC Integrative Epidemiology Unit, School of Social and Community Medicine, University of Bristol, Bristol, UK
| | - Ronald P Stolk
- Department of Epidemiology, University Medical Center, University of Groningen, Groningen, Netherlands
| | - Dena G Hernandez
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD, USA
| | - Liisa Byberg
- Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - Emil Hagström
- Uppsala Clinical Research Centre, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Håkan Melhus
- Uppsala Clinical Research Centre, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Erik Ingelsson
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK; Uppsala Clinical Research Centre, Department of Medical Sciences, Uppsala University, Uppsala, Sweden; Molecular Epidemiology and Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Dan Mellström
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Osten Ljunggren
- Uppsala Clinical Research Centre, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Ioanna Tzoulaki
- Faculty of Medicine, School of Public Health, Imperial College London, London, UK
| | - Stela McLachlan
- Centre for Population Health Sciences, University of Edinburgh, Edinburgh, UK
| | - Evropi Theodoratou
- Centre for Population Health Sciences, University of Edinburgh, Edinburgh, UK
| | - Carla M T Tiesler
- Institute of Epidemiology I, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, Germany; Institute of Medical Informatics, Biometry and Epidemiology, Ludwig Maximilian University of Munich, Dr von Hauner Children's Hospital, Munich, Germany
| | - Antti Jula
- Department of Chronic Disease Prevention, National Institute for Health and Welfare, Turku, Finland
| | - Pau Navarro
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Alan F Wright
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Ozren Polasek
- Croatian Centre for Global Health, University of Split Medical School, Split, Croatia
| | | | | | | | | | - James F Wilson
- Centre for Population Health Sciences, University of Edinburgh, Edinburgh, UK
| | - Igor Rudan
- Centre for Population Health Sciences, University of Edinburgh, Edinburgh, UK
| | - Veikko Salomaa
- National Institute for Health and Welfare, Helsinki, Finland
| | - Joachim Heinrich
- Institute of Epidemiology I, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, Germany
| | - Harry Campbell
- Centre for Population Health Sciences, University of Edinburgh, Edinburgh, UK
| | - Jacqueline F Price
- Centre for Population Health Sciences, University of Edinburgh, Edinburgh, UK
| | - Magnus Karlsson
- Clinical and Molecular Osteoporosis Research Unit, Department of Clinical Sciences and Orthopaedic Surgery, Lund University, Skåne University Hospital, Malmö, Sweden
| | - Lars Lind
- Uppsala Clinical Research Centre, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Karl Michaëlsson
- Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | | | - Timothy M Frayling
- Genetics of Complex Traits, University of Exeter Medical School, Exeter, UK
| | - Catharina A Hartman
- Department of Psychiatry, University Medical Center, University of Groningen, Groningen, Netherlands
| | - Thorkild I A Sørensen
- Metabolic Genetics, Novo Nordisk Foundation Centre for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Institute of Preventive Medicine, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
| | - Stephen B Kritchevsky
- Gerontology and Geriatric Medicine, Department of Internal Medicine, and J Paul Sticht Center on Aging, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Bente Lomholt Langdahl
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Johan G Eriksson
- Department of General Practice and Primary Health Care, University of Helsinki, Helsinki, Finland; Vasa Central Hospital, Vasa, Finland; Folkhälsan Research Centre, Helsinki, Finland; Unit of General Practice, Helsinki University Central Hospital, Helsinki, Finland
| | - Jose C Florez
- Center for Human Genetic Research and Diabetes Research Center, Massachusetts General Hospital, Boston, MA, USA
| | - Tim D Spector
- Department of Twin Research & Genetic Epidemiology, King's College London, St Thomas' Campus, London, UK
| | - Terho Lehtimäki
- Department of Clinical Chemistry, Fimlab Laboratories and School of Medicine, University of Tampere, Tampere, Finland
| | - Diana Kuh
- MRC Unit for Lifelong Health and Ageing, University College London, London, UK
| | - Steve E Humphries
- Cardiovascular Genetics, BHF Laboratories, Institute of Cardiovascular Science, University College London, London, UK
| | - Cyrus Cooper
- NIHR Oxford Musculoskeletal Biomedical Research Unit, University of Oxford, Oxford, UK; MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK
| | - Claes Ohlsson
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Winfried März
- Medical Clinic V (Nephrology, Hypertensiology, Rheumatology, Endocrinology, Diabetology), Mannheim Medical Faculty, University of Heidelberg, Mannheim, Germany; Synlab Academy, Mannheim, Germany; Department of Internal Medicine, Division of Endocrinology and Metabolism, and Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
| | - Martin H de Borst
- Department of Internal Medicine, Division of Nephrology, University Medical Center, University of Groningen, Groningen, Netherlands
| | - Meena Kumari
- Department of Epidemiology and Public Health, University College London, London, UK
| | - Mika Kivimaki
- Department of Epidemiology and Public Health, University College London, London, UK
| | - Thomas J Wang
- Division of Cardiovascular Medicine, Vanderbilt University, Nashville, TN, USA
| | - Chris Power
- Population, Policy and Practice, UCL Institute of Child Health, London, UK
| | - Hermann Brenner
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center, Heidelberg, Germany
| | - Guri Grimnes
- Tromsø Endocrine Research Group, Department of Clinical Medicine, University of Tromsø, Tromsø, Norway
| | - Pim van der Harst
- Department of Cardiology, University Medical Center, University of Groningen, Groningen, Netherlands
| | - Harold Snieder
- Department of Epidemiology, University Medical Center, University of Groningen, Groningen, Netherlands
| | | | - Stefan Pilz
- Department of Internal Medicine, Division of Endocrinology and Metabolism, and Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
| | | | - Marjo-Riitta Järvelin
- Department of Epidemiology and Biostatistics, Imperial College London, London, UK; MRC-PHE Centre for Environment & Health, Imperial College London, London, UK; Biocenter Oulu, University of Oulu, Oulu, Finland; Institute of Health Sciences, University of Oulu, Oulu, Finland; Unit of Primary Care, Oulu University Hospital, Oulu, Finland; National Institute for Health and Welfare, Oulu, Finland
| | - Elina Hyppönen
- Population, Policy and Practice, UCL Institute of Child Health, London, UK; School of Population Health, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia; South Australian Health and Medical Research Institute, Adelaide, SA, Australia.
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Ellam T. Confounded complexity: vitamin d, parathyroid hormone, and metabolic syndrome in peritoneal dialysis. Perit Dial Int 2014; 34:333-7. [PMID: 24991048 DOI: 10.3747/pdi.2014.00005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Affiliation(s)
- Timothy Ellam
- Sheffield Kidney Institute Department of Cardiovascular Science University of Sheffield Sheffield, UK
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Zelenchuk LV, Hedge AM, Rowe PSN. PHEX mimetic (SPR4-peptide) corrects and improves HYP and wild type mice energy-metabolism. PLoS One 2014; 9:e97326. [PMID: 24839967 PMCID: PMC4026222 DOI: 10.1371/journal.pone.0097326] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 04/17/2014] [Indexed: 12/19/2022] Open
Abstract
CONTEXT PHEX or DMP1 mutations cause hypophosphatemic-rickets and altered energy metabolism. PHEX binds to DMP1-ASARM-motif to form a complex with α5β3 integrin that suppresses FGF23 expression. ASARM-peptides increase FGF23 by disrupting the PHEX-DMP1-Integrin complex. We used a 4.2 kDa peptide (SPR4) that binds to ASARM-peptide/motif to study the DMP1-PHEX interaction and to assess SPR4 for the treatment of energy metabolism defects in HYP and potentially other bone-mineral disorders. DESIGN Subcutaneously transplanted osmotic pumps were used to infuse SPR4-peptide or vehicle (VE) into wild-type mice (WT) and HYP-mice (PHEX mutation) for 4 weeks. RESULTS SPR4 partially corrected HYP mice hypophosphatemia and increased serum 1.25(OH)2D3. Serum FGF23 remained high and PTH was unaffected. WT-SPR4 mice developed hypophosphatemia and hypercalcemia with increased PTH, FGF23 and 1.25(OH)2D3. SPR4 increased GAPDH HYP-bone expression 60× and corrected HYP-mice hyperglycemia and hypoinsulinemia. HYP-VE serum uric-acid (UA) levels were reduced and SPR4 infusion suppressed UA levels in WT-mice but not HYP-mice. SPR4 altered leptin, adiponectin, and sympathetic-tone and increased the fat mass/weight ratio for HYP and WT mice. Expression of perlipin-2 a gene involved in obesity was reduced in HYP-VE and WT-SPR4 mice but increased in HYP-SPR4 mice. Also, increased expression of two genes that inhibit insulin-signaling, ENPP1 and ESP, occurred with HYP-VE mice. In contrast, SPR4 reduced expression of both ENPP1 and ESP in WT mice and suppressed ENPP1 in HYP mice. Increased expression of FAM20C and sclerostin occurred with HYP-VE mice. SPR4 suppressed expression of FAM20C and sclerostin in HYP and WT mice. CONCLUSIONS ASARM peptides and motifs are physiological substrates for PHEX and modulate osteocyte PHEX-DMP1-α5β3-integrin interactions and thereby FGF23 expression. These interactions also provide a nexus that regulates bone and energy metabolism. SPR4 suppression of sclerostin and/or sequestration of ASARM-peptides improves energy metabolism and may have utility for treating familial rickets, osteoporosis, obesity and diabetes.
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Affiliation(s)
- Lesya V. Zelenchuk
- Internal Medicine, The Kidney Institute, Kansas University Medical Center (KUMC), Kansas City, Kansas, United States of America
| | - Anne-Marie Hedge
- Internal Medicine, The Kidney Institute, Kansas University Medical Center (KUMC), Kansas City, Kansas, United States of America
| | - Peter S. N. Rowe
- Internal Medicine, The Kidney Institute, Kansas University Medical Center (KUMC), Kansas City, Kansas, United States of America
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Mutations in the vitamin D receptor and hereditary vitamin D-resistant rickets. BONEKEY REPORTS 2014; 3:510. [PMID: 24818002 DOI: 10.1038/bonekey.2014.5] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 09/27/2013] [Indexed: 12/24/2022]
Abstract
Heterogeneous loss of function mutations in the vitamin D receptor (VDR) interfere with vitamin D signaling and cause hereditary vitamin D-resistant rickets (HVDRR). HVDRR is characterized by hypocalcemia, secondary hyperparathyroidism and severe early-onset rickets in infancy and is often associated with consanguinity. Affected children may also exhibit alopecia of the scalp and total body. The children usually fail to respond to treatment with calcitriol; in fact, their endogenous levels are often very elevated. Successful treatment requires reversal of hypocalcemia and secondary hyperparathyroidism and is usually accomplished by administration of high doses of calcium given either intravenously or sometimes orally to bypass the intestinal defect in VDR signaling.
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Pilz S, Gaksch M, O'Hartaigh B, Tomaschitz A, März W. The role of vitamin D deficiency in cardiovascular disease: where do we stand in 2013? Arch Toxicol 2013; 87:2083-103. [PMID: 24173581 DOI: 10.1007/s00204-013-1152-z] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 10/22/2013] [Indexed: 12/14/2022]
Abstract
The high worldwide prevalence of vitamin D deficiency is largely the result of low sunlight exposure with subsequently limited cutaneous vitamin D production. Classic manifestations of vitamin D deficiency are linked to disturbances in bone and mineral metabolism, but the identification of the vitamin D receptor in almost every human cell suggests a broader role of vitamin D for overall and cardiovascular health. The various cardiovascular protective actions of vitamin D such as anti-diabetic and anti-hypertensive effects including renin suppression as well as protection against atherosclerosis and heart diseases are well defined in previous experimental studies. In line with this, large epidemiological studies have highlighted vitamin D deficiency as a marker of cardiovascular risk. However, randomized controlled trials (RCTs) on vitamin D have largely failed to show its beneficial effects on cardiovascular diseases and its conventional risk factors. While most prior vitamin D RCTs were not designed to assess cardiovascular outcomes, some large RCTs have been initiated to evaluate the efficacy of vitamin D supplementation on cardiovascular events in the general population. When considering the history of previous disappointing vitamin RCTs in general populations, more emphasis should be placed on RCTs among severely vitamin D-deficient populations who would most likely benefit from vitamin D treatment. At present, vitamin D deficiency can only be considered a cardiovascular risk marker, as vitamin D supplementation with doses recommended for osteoporosis treatment is neither proven to be beneficial nor harmful in cardiovascular diseases.
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Affiliation(s)
- Stefan Pilz
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria,
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19
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Viljoen A. Vitamin D and cardiovascular disease - dilemma, delight or 'dont know?'. Int J Clin Pract 2013; 67:939-42. [PMID: 24073970 DOI: 10.1111/ijcp.12197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 04/20/2013] [Indexed: 11/28/2022] Open
Abstract
The current lack of sufficient evidence of vitamin D's role in CVD calls for perspective and caution to avoid that health claims, vitamin D testing and supplementations' sales will continue to run well ahead of the scientific evidence.
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Affiliation(s)
- Adie Viljoen
- Clinical Biochemistry, Lister Hospital, Coreys Mill Lane, Stevenage, United Kingdom.
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20
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Abstract
Vitamin D receptors (VDR) are found in cells throughout the cardiovascular system. A variety of experimental studies indicate that the liganded VDR may play an important role in controlling cardiac hypertrophy and fibrosis, regulating blood pressure, and suppressing the development of atherosclerosis. Some, but not all, observational studies in humans provide support for these experimental findings, raising the possibility that vitamin D or its analogs might prove useful therapeutically in the prevention or treatment of cardiovascular disease.
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Affiliation(s)
- David G Gardner
- Diabetes Center, University of California at San Francisco, San Francisco, California; and
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Larsen T, Mose FH, Bech JN, Pedersen EB. Effect of paricalcitol on renin and albuminuria in non-diabetic stage III-IV chronic kidney disease: a randomized placebo-controlled trial. BMC Nephrol 2013; 14:163. [PMID: 23889806 PMCID: PMC3729723 DOI: 10.1186/1471-2369-14-163] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Accepted: 07/19/2013] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Vitamin D receptor activators reduce albuminuria, and may improve survival in chronic kidney disease (CKD). Animal studies suggest that these pleiotropic effects of vitamin D may be mediated by suppression of renin. However, randomized trials in humans have yet to establish this relationship. METHODS In a randomized, placebo-controlled, double-blinded crossover study, the effect of oral paricalcitol (2 μg/day) was investigated in 26 patients with non-diabetic, albuminuric stage III-IV CKD. After treatment, plasma concentrations of renin (PRC), angiotensin II (AngII) and aldosterone (Aldo) were measured. GFR was determined by 51Cr-EDTA clearance. Assessment of renal NO dependency was performed by infusion of NG-monomethyl-L-arginine (L-NMMA). Albumin excretion rate (AER) was analyzed in 24-h urine and during 51Cr-EDTA clearance. RESULTS Paricalcitol did not alter plasma levels of renin, AngII, Aldo, or urinary excretion of sodium and potassium. A modest reduction of borderline significance was observed in AER, and paricalcitol abrogated the albuminuric response to L-NMMA. CONCLUSIONS In this randomized, placebo-controlled trial paricalcitol only marginally decreased AER and did not alter circulating levels of renin, AngII or Aldo. The abrogation of the rise in albumin excretion by paricalcitol during NOS blockade may indicate that favourable modulation of renal NO dependency could be involved in mediating reno-protection and survival benefits in CKD. TRIAL REGISTRATION ClinicalTrials.gov identifier: NCT01136564.
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Abstract
Vitamin-D-related pathways are implicated in various endocrine, inflammatory and endothelial functions. An estimated 1 billion people in the world have vitamin D deficiency or insufficiency, and undiagnosed vitamin D deficiency is common. Vitamin D deficiency is associated with substantial increases in the incidence of hypertension, hyperlipidaemia, myocardial infarction and stroke, as well as in diseases such as chronic kidney disease and type 2 diabetes. Low vitamin D levels also upregulate the renin-angiotensin-aldosterone system, increase inflammation and cause endothelial dysfunction. However, the role of vitamin D deficiency in cardiovascular morbidity and mortality is an emerging and hotly debated topic. Epidemiological studies suggest an association between low vitamin D levels and risk factors for cardiovascular disease, but a causal relationship has not been established, and clinical trials and meta-analyses have not demonstrated convincing evidence that vitamin D therapy improves cardiovascular outcomes. Some evidence suggests that vitamin D status is a biomarker of lifestyle, since unhealthy and sedentary lifestyles are associated with vitamin D insufficiency or deficiency and are also risk factors for cardiovascular complications.
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Bernini G, Carrara D, Bacca A, Carli V, Virdis A, Rugani I, Duranti E, Ghiadoni L, Bernini M, Taddei S. Effect of acute and chronic vitamin D administration on systemic renin angiotensin system in essential hypertensives and controls. J Endocrinol Invest 2013; 36:216-20. [PMID: 23645099 DOI: 10.1007/bf03347275] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
AIM To investigate the systemic renin-angiotensin system (RAS) in essential hypertensives (EH) and controls (C) after short- and long-term vitamin D receptor activation. DESIGN Ten consecutive EH (under controlled low-salt diet) and 10 C underwent calcitriol administration (0.25 μg bid) for 1 week (Group A). Eighteen consecutive EH under angiotensin II receptor antagonist therapy received a single oral dose of 300,000 IU of cholecalciferol and were followed up for 8 weeks (Group B). METHODS In basal conditions and at the end of the study (1 week in Group A and 8 weeks in Group B), plasma renin activity (PRA), plasma active renin, aldosterone, and angiotensin II were evaluated, as well as blood pressure, plasma 25-hydroxyvitamin D [25(OH)D], 1,25-dihydroxyvitamin D [1,25(OH)2D], and PTH. RESULTS In Group A, plasma 25(OH)D levels in EH and C were below the normal range, although lower levels were found in the former. No association between basal plasma 25(OH)D or 1,25(OH)2D levels and blood pressure values or RAS components was observed either in the whole group or in the two subgroups. Calcitriol administration did not affect any RAS parameter either in EH or in C. In Group B, cholecalciferol significantly increased 25(OH)D and 1,25(OH)2D levels without interfering with the angiotensin II receptor antagonist-induced increase in RAS components. No correlation was found between plasma 25(OH)D or 1,25(OH)2D levels and blood pressure values or RAS parameters before and after cholecalciferol administration. CONCLUSIONS The present data suggest that, in our experimental conditions, vitamin D receptor activation is unable to influence systemic RAS activity.
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Affiliation(s)
- G Bernini
- Department of Internal Medicine, University of Pisa, Via Roma 67, 56100 Pisa, Italy.
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24
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Ameri P, Canepa M, Milaneschi Y, Spallarossa P, Leoncini G, Giallauria F, Strait JB, Lakatta EG, Brunelli C, Murialdo G, Ferrucci L. Relationship between vitamin D status and left ventricular geometry in a healthy population: results from the Baltimore Longitudinal Study of Aging. J Intern Med 2013; 273:253-62. [PMID: 23061475 PMCID: PMC3568460 DOI: 10.1111/joim.12007] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
OBJECTIVES The effects of vitamin D on the heart have been studied in patients with cardiac disease, but not in healthy persons. We investigated the relation between vitamin D status and left ventricular (LV) structure and function in community-dwelling subjects without heart disease. DESIGN The relationship between concentrations of 25-hydroxyvitamin D [25(OH)D], a marker of vitamin D reserve, and LV transthoracic echocardiography measures was analysed in 711 participants in the Baltimore Longitudinal Study of Aging who were without cardiac disease. RESULTS Mean 25(OH)D in the study population was 32.3 ± 11.4 ng mL(-1) ; only 15.5% of subjects had moderate or severe vitamin D deficiency [25(OH)D < 20 ng mL(-1) ]. Adjusting for age, body mass index, cardiovascular disease risk factors, physical activity, calcium and parathyroid hormone, 25(OH)D was positively correlated with LV thickness (β 0.095, SE 0.039, P < 0.05) and LV mass index (β 7.5, SE 2.6, P < 0.01). A significant nonlinear relation between 25(OH)D and LV concentric remodelling was observed. LV remodelling was more likely in participants with 25(OH)D levels <30 ng mL(-1) [odds ratio (OR) 1.24; 95% confidence interval (CI) 0.83-1.85] or ≥38 ng mL(-1) (OR 1.73; 95% CI 1.13-2.65), compared with those with 30-37 ng mL(-1) 25(OH)D. Consistently, LV relative wall thickness was significantly lower (P for trend=0.05), and LV diastolic internal diameter index (P for trend<0.05) and end-diastolic volume index (P for trend<0.05) were significantly higher in subjects with 30-37 ng mL(-1) 25(OH)D compared to the rest of the study population. There was a significant interaction between 25(OH)D and hypertension on the risk of LV hypertrophy (P < 0.05). CONCLUSIONS In a population-based sample of predominantly vitamin D-sufficient subjects without heart disease, LV geometry was most favourable at intermediate 25(OH)D concentrations.
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Affiliation(s)
- P Ameri
- Department of Internal Medicine, University of Genova, Genova, Italy.
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Andrukhova O, Slavic S, Zeitz U, Riesen SC, Heppelmann MS, Ambrisko TD, Markovic M, Kuebler WM, Erben RG. Vitamin D is a regulator of endothelial nitric oxide synthase and arterial stiffness in mice. Mol Endocrinol 2013; 28:53-64. [PMID: 24284821 DOI: 10.1210/me.2013-1252] [Citation(s) in RCA: 173] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The vitamin D hormone 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3] is essential for the preservation of serum calcium and phosphate levels but may also be important for the regulation of cardiovascular function. Epidemiological data in humans have shown that vitamin D insufficiency is associated with hypertension, left ventricular hypertrophy, increased arterial stiffness, and endothelial dysfunction in normal subjects and in patients with chronic kidney disease and type 2 diabetes. However, the pathophysiological mechanisms underlying these associations remain largely unexplained. In this study, we aimed to decipher the mechanisms by which 1,25(OH)2D3 may regulate systemic vascular tone and cardiac function, using mice carrying a mutant, functionally inactive vitamin D receptor (VDR). To normalize calcium homeostasis in VDR mutant mice, we fed the mice lifelong with the so-called rescue diet enriched with calcium, phosphate, and lactose. Here, we report that VDR mutant mice are characterized by lower bioavailability of the vasodilator nitric oxide (NO) due to reduced expression of the key NO synthesizing enzyme, endothelial NO synthase, leading to endothelial dysfunction, increased arterial stiffness, increased aortic impedance, structural remodeling of the aorta, and impaired systolic and diastolic heart function at later ages, independent of changes in the renin-angiotensin system. We further demonstrate that 1,25(OH)2D3 is a direct transcriptional regulator of endothelial NO synthase. Our data demonstrate the importance of intact VDR signaling in the preservation of vascular function and may provide a mechanistic explanation for epidemiological data in humans showing that vitamin D insufficiency is associated with hypertension and endothelial dysfunction.
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Affiliation(s)
- Olena Andrukhova
- Department of Biomedical Research (O.A., S.S., U.Z., M.S.H., R.G.E.) and Department for Companion Animals and Horses (S.C.R., T.D.A., M.M.), University of Veterinary Medicine Vienna, 1210 Vienna, Austria; and Institute for Surgical Research (W.M.K.), Ludwig Maximilians University, 80539 Munich, Germany
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Shroff R, Wan M, Rees L. Can vitamin D slow down the progression of chronic kidney disease? Pediatr Nephrol 2012; 27:2167-73. [PMID: 22160397 DOI: 10.1007/s00467-011-2071-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 11/05/2011] [Accepted: 11/08/2011] [Indexed: 12/17/2022]
Abstract
Pharmacological blockade of the renin-angiotensin-aldosterone system (RAAS) is the cornerstone of renoprotective therapy, and the reduction of persistent RAAS activation is considered to be an important target in the treatment of chronic kidney disease (CKD). Vitamin D is a steroid hormone that controls a broad range of metabolic and cell regulatory functions. It acts as a transcription factor and can suppress the renin gene, thereby acting as a negative endocrine regulator of RAAS. RAAS activation can reduce renal Klotho expression, and the Klotho-fibroblast growth factor 23 interaction may further reduce the production of active vitamin D. Results from both clinical and experimental studies suggest that vitamin D therapy is associated with a reduction in blood pressure and left ventricular hypertrophy and improves cardiovascular outcomes. In addition, a reduction in angiotensin II through RAAS blockade may have anti-proteinuric and anti-fibrotic effects. Vitamin D has also been shown to modulate the immune system, regulate inflammatory responses, improve insulin sensitivity and reduce high-density lipoprotein cholesterol. Taken together, these pleiotropic effects of vitamin D may slow down the progression of CKD. In this review, we discuss the experimental and early clinical findings that suggest a renoprotective effect of vitamin D, thereby providing an additional rationale beyond mineral metabolism for the close monitoring of, and supplementation with vitamin D from the earliest stages of CKD.
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Affiliation(s)
- Rukshana Shroff
- Renal Unit, Great Ormond Street Hospital for Children NHS Trust, Great Ormond Street, London, WC1N 3JH, UK.
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Tiosano D, Gepstein V. Vitamin D action: lessons learned from hereditary 1,25-dihydroxyvitamin-D-resistant rickets patients. Curr Opin Endocrinol Diabetes Obes 2012; 19:452-9. [PMID: 23128575 DOI: 10.1097/med.0b013e32835a3415] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PURPOSE OF REVIEW Hereditary 1,25-dihydroxyvitamin-D [1,25(OH)(2)D(3)]-resistant rickets (HVDRR) is a rare genetic disease caused by generalized resistance to 1,25(OH)(2)D(3). Less than 100 cases are reported in the literature. These patients provide an experiment by nature enabling us to understand the role of vitamin D, especially in light of the ongoing debate concerning normal vitamin D levels and the supplement dosage that should be recommended. This article summarizes the role of vitamin D in calcium absorption, rennin-angiotensin system (RAS), and cardiac state in HVDRR patients. RECENT FINDINGS The precise spectrum of vitamin D activities can now be better evaluated by critical analysis of mouse models with targeted deletion of the gene encoding the vitamin D receptor (VDR). Of special interest is the unraveling of the role of VDR in calcium absorption and cardiac status in VDR-knockout mice. The facts that VDR-knockout mice up-regulate intestinal calcium absorption and skeletal mineralization independently of the VDR during pregnancy and lactation point to the existence of VDR-independent mechanisms that are involved in calcium absorption. The observation that mice with genetic disruption of the 1α-hydroxylase gene or of the VDR gene have an overstimulated RAS and consequently develop high blood pressure and cardiac hypertrophy raised concern about potential risks to the cardiovascular system in HVDRR patients. SUMMARY The current review summarizes the new understanding of the effects of vitamin D on calcium absorption, the RAS, and heart hypertrophy derived from studying HVDRR patients from infancy to their mid-30s.
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Affiliation(s)
- Dov Tiosano
- Pediatric Endocrinology, Meyer Children's Hospital, Rambam Healthcare Campus, Haifa, Israel.
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Abstract
The prevalence of both hypertension and vitamin D deficiency is high. The discovery of the vitamin D receptor and its possible effects on components of the cardiovascular system influencing blood pressure, such as the renin angiotensin system, the heart, the kidney and the blood vessels, has generated the hope that vitamin D therapy could be a new target for the treatment for hypertensive patients. Cross-sectional studies have clearly shown an association between low levels of vitamin D and hypertension. This association is not as clear in longitudinal studies. Finally, evidence from randomized controlled trials specifically designed to test the hypothesis of a blood pressure lowering effect of vitamin D is weak. Therefore, there is actually not enough evidence to recommend giving vitamin D to reduce blood pressure in hypertensive patients.
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Affiliation(s)
- Gregoire Wuerzner
- Service of nephrology and hypertension, Lausanne University Hospital, Lausanne, Switzerland
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Effect of cholecalciferol supplementation during winter months in patients with hypertension: a randomized, placebo-controlled trial. Am J Hypertens 2012; 25:1215-22. [PMID: 22854639 DOI: 10.1038/ajh.2012.111] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Low 25-hydroxy-vitamin D (25(OH)D) levels are inversely related to blood pressure (BP) and have been associated with incident hypertension. In people living at northern latitudes diminished cholecalciferol synthesis in the winter increases the risk of vitamin D deficiency. We wanted to test the hypothesis that daily cholecalciferol supplementation in the winter lowers BP in patients with hypertension. METHODS We investigated the effect of 75 µg (3,000 IU) cholecalciferol per day in a randomized, placebo-controlled, double-blind study in 130 hypertensive patients residing in Denmark (56º N). Ambulatory BP (24-h BP) and arterial stiffness were measured before and after 20 weeks of treatment, that took place between October and March. RESULTS A total of 112 patients (mean age 61 ± 10) with a baseline p-25(OH)D of 23 ± 10 ng/ml completed the study. Compared with placebo, a nonsignificant 3/1 mm Hg (P = 0.26/0.18) reduction was found in 24-h BP. In patients with vitamin D insufficiency (<32 ng/ml) at baseline (n = 92), 24-h BP decreased by 4/3 mm Hg (P = 0.05/0.01). Central BP (CBP) estimated by applanation tonometry and calibrated with a standardized office BP was reduced by 7/2 mm Hg (P = 0.007/0.15) vs. placebo. No differences in carotid-femoral pulse wave velocity (PWV) or central augmentation index (AIx) were found between treatment arms. CONCLUSIONS Cholecalciferol supplementation, by a dose that effectively increased vitamin D levels, did not reduce 24-h BP, although central systolic BP decreased significantly. In a post-hoc subgroup analysis of 92 subjects with baseline p-25(OH)D levels <32 ng/ml, significant decreases in 24-h systolic and diastolic BP occurred during cholecalciferol supplementation.
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Abstract
The kidney is the major, if not sole, site for the production of 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3), the biologically active form of vitamin D that can stimulate calcium reabsorption in the kidney and may provide renoprotective benefits. The biological effects of 1,25(OH)2D3 are mediated through a nuclear hormone receptor, known as the vitamin D receptor (VDR). It is well accepted that the VDR is present in the distal renal convoluted tubule cells; however, whether VDR is present in other kidney cell types is uncertain. Using a highly specific and sensitive anti-VDR antibody, we determined its distribution in the mouse kidney by immunohistochemistry. Our results show that the VDR is not only present in the distal but is also found in the proximal tubules, but at 24-fold lower levels. The VDR was also found in the macula densa of the juxtaglomerular apparatus, glomerular parietal epithelial cells, and podocytes. In contrast, the VDR is either very low or absent in interstitial fibroblasts, glomerular mesangial cells, and juxtaglomerular cells. Thus, identification of VDR in the proximal tubule, macula densa, and podocytes suggests that 1,25(OH)2D3 plays a direct role in these cells under normal conditions.
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