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Cavalier É, Thervet É, Courbebaisse M. Vitamine D et rein. Presse Med 2013; 42:1391-7. [DOI: 10.1016/j.lpm.2013.07.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 07/10/2013] [Accepted: 07/15/2013] [Indexed: 02/08/2023] Open
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Abstract
Vitamin D metabolism consists of both production and catabolism, which are enzymatically driven and highly regulated. Renal vitamin D metabolism requires filtration and tubular reabsorption of 25-hydroxyvitamin D and is regulated by parathyroid hormone, fibroblast growth factor-23, and 1,25-dihydroxyvitamin D. In chronic kidney disease, renal production of 1,25-dihydroxyvitamin D from 25-hydroxyvitamin D is reduced. In addition, pharmacokinetic studies and epidemiologic studies of 24,25-dihydroxyvitamin D, the most abundant product of 25-hydroxyvitamin D catabolism by CYP24A1, suggest that vitamin D catabolism also is reduced. New insights into the mechanisms and regulation of vitamin D metabolism may lead to novel approaches to assess and treat impaired vitamin D metabolism in chronic kidney disease.
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Affiliation(s)
- Cortney Bosworth
- Division of Nephrology and Kidney Research Institute, University of Washington, Seattle, WA, USA
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Rangan GK, Schwensen KG, Foster SL, Korgaonkar MS, Peduto A, Harris DC. Chronic effects of dietary vitamin D deficiency without increased calcium supplementation on the progression of experimental polycystic kidney disease. Am J Physiol Renal Physiol 2013; 305:F574-82. [PMID: 23698116 DOI: 10.1152/ajprenal.00411.2012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Increasing evidence indicates that vitamin D deficiency exacerbates chronic kidney injury, but its effects on renal enlargement in polycystic kidney disease (PKD) are not known. In this study, male Lewis polycystic kidney disease (LPK) rats received a normal diet (ND; AIN-93G) supplemented with or without cholecalciferol (vitamin D-deficient diet, VDD; both 0.5% calcium), commenced at either postnatal week 3 (until weeks 10-20; study 1) or from week 10 (until week 20; study 2). Levels of 25-hydroxy vitamin D were reduced in groups receiving the VDD (12 ± 1 nmol/l vs. 116 ± 5 in ND; P < 0.001). In study 1, food intake and weight gain increased by ∼25% in LPK rats receiving the VDD ad libitum, and at week 20 this was associated with a mild reduction in the corrected serum calcium (SCa(2+), 7.4%) and TKW:BW ratio (8.8%), and exacerbation of proteinuria (87%) and hypertension (19%; all P < 0.05 vs. ND). When LPK rats were pair-fed for weeks 3-10, there was a further reduction in the SCa(2+) (25%) and TKW:BW ratio (22%) in the VDD group (P < 0.05 vs. ND). In study 2, the VDD did not alter food intake and body weight, reduced SCa(2+) (7.7%), worsened proteinuria (41.9%), interstitial monocyte accumulation (26.4%), renal dysfunction (21.4%), and cardiac enlargement (13.2%, all P < 0.05), but there was a trend for a reduction in the TKW:BW ratio (13%, P = 0.09). These data suggest that chronic vitamin D deficiency has adverse long-term actions on proteinuria, interstitial inflammation, renal function, and cardiovascular disease in PKD, and these negate its mild inhibitory effect on kidney enlargement.
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Affiliation(s)
- Gopala K Rangan
- Centre for Transplant and Renal Research, Level 2, Clinical Sciences Block, Westmead Hospital, Cnr Bridge and Darcy Rds., Westmead, NSW, Australia 2145.
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Ahmadi N, Mortazavi M, Iraj B, Askari G. Whether vitamin D3 is effective in reducing proteinuria in type 2 diabetic patients? JOURNAL OF RESEARCH IN MEDICAL SCIENCES : THE OFFICIAL JOURNAL OF ISFAHAN UNIVERSITY OF MEDICAL SCIENCES 2013; 18:374-7. [PMID: 24174939 PMCID: PMC3810568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 03/28/2013] [Accepted: 04/08/2013] [Indexed: 11/17/2022]
Abstract
BACKGROUND Nowadays Vitamin D deficiency is a notable medical condition world-wide and also in Iran. Since, vitamin D can have renoprotective effect by inhibiting the renin-angiotensin system; it appears that low vitamin D level can worsen the renal injury in diabetic patients. This study demonstrates the effect of vitamin D3 therapy on reducing proteinuria in diabetic patients with concomitant diabetic nephropathy and vitamin D deficiency after controlling hypertension and use of angiotensin converting enzyme inhibitors (ACEIs) or angiotensin II type receptor blockers (ARBs). MATERIALS AND METHODS In this randomized double blinded parallel groups clinical trial, 51 diabetic patients with proven nephropathy and vitamin D deficiency/insufficiency and stable hypertension, dyslipidemia, and hyperglycemic treatment were enrolled. The patients were divided randomly into two groups (treatment and placebo group). Patients received oral vitamin D3 (pearl 50000 IU) or placebo one pearl every week for 12 weeks. Patients were assessed at baseline and 12 weeks after intervention from the point of 25(OH) D level, and urine albumin/creatinine ration (UACR). RESULTS Mean serum 25(OH) D concentrations were 14.06 ng/ml and 16.05 ng/ml before treatment. Furthermore, after intervention, its levels were risen to 71.23 and 17.63 in drug and placebo groups, respectively. Whereas, UACR as the main variable did not change significantly after intervention in both groups (P = 0.919). CONCLUSION According to our finding, there was not a decrease in proteinuria in diabetic patients who received vitamin D for a period of 3 months.
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Affiliation(s)
- Nooshin Ahmadi
- Resident of Internal Medicine, Isfahan Kidney Diseases Research Center, Isfahan University of Medical Sciences,Isfahan, Iran
| | - Mojgan Mortazavi
- Department of Nephrology, Isfahan Kidney Diseases Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Bijan Iraj
- Department of Clinical Nutrition, Isfahan Endocrine and Metabolism Research Center, Isfahan, Iran,Address for correspondence: Dr. Bijan Iraj, Isfahan Endocrine and Metabolism Research Centre, Sedighe Tahereh Research Centre, Khoram Street, Isfahan, Iran. E-mail:
| | - Gholamreza Askari
- Assistant professor of endocrinology, Isfahan Endocrine and Metabolism Research Center, Isfahan, Iran
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Kermanizadeh A, Vranic S, Boland S, Moreau K, Baeza-Squiban A, Gaiser BK, Andrzejczuk LA, Stone V. An in vitro assessment of panel of engineered nanomaterials using a human renal cell line: cytotoxicity, pro-inflammatory response, oxidative stress and genotoxicity. BMC Nephrol 2013; 14:96. [PMID: 23617532 PMCID: PMC3648395 DOI: 10.1186/1471-2369-14-96] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 04/17/2013] [Indexed: 12/11/2022] Open
Affiliation(s)
- Ali Kermanizadeh
- Heriot-Watt University, School of Life Sciences, Edinburgh, EH14 4AS, UK.
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Association of low serum 25-hydroxyvitamin D levels and acute kidney injury in the critically ill. Crit Care Med 2013; 40:3170-9. [PMID: 22975885 DOI: 10.1097/ccm.0b013e318260c928] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Given the importance of inflammation in acute kidney injury and the relationship between vitamin D and inflammation, we sought to elucidate the effect of vitamin D on acute kidney injury. We hypothesized that deficiency in 25-hydroxyvitamin D prior to hospital admission would be associated with acute kidney injury in the critically ill. DESIGN Two-center observational study of patients treated in medical and surgical intensive care units. SETTING Two hundred nine medical and surgical intensive care beds in two teaching hospitals in Boston, Massachusetts. PATIENTS Two thousand seventy-five patients, aged ≥ 18 yrs, in whom serum 25-hydroxyvitamin D was measured prior to hospitalization between 1998 and 2009. INTERVENTIONS : None. MEASUREMENTS AND MAIN RESULTS The exposure of interest was preadmission serum 25-hydroxyvitamin D and categorized a priori as deficiency (25-hydroxyvitamin D <15 ng/mL), insufficiency (25-hydroxyvitamin D 15-30 ng/mL), or sufficiency (25-hydroxyvitamin D ≥ 30 ng/mL). The primary outcome was acute kidney injury defined as meeting Risk, Injury, Failure, Loss, and End-stage kidney disease (RIFLE) Injury or Failure criteria. Logistic regression examined the RIFLE criteria outcome. Adjusted odds ratios were estimated by multivariate logistic regression models. Preadmission 25-hydroxyvitamin D deficiency is predictive of acute kidney injury. Patients with 25-hydroxyvitamin D deficiency have an odds ratio for acute kidney injury of 1.73 (95% confidence interval 1.30-2.30; p < .0001) relative to patients with 25-hydroxyvitamin D sufficiency. 25-Hydroxyvitamin D deficiency remains a significant predictor of acute kidney injury following multivariable adjustment (adjusted odds ratio 1.50; 95% confidence interval 1.42-2.24; p < .0001). Patients with 25-hydroxyvitamin D insufficiency have an odds ratio for acute kidney injury of 1.49 (95% confidence interval 1.15-1.94; p = .003) and an adjusted odds ratio of 1.23 (95% confidence interval 1.12-1.72; p = .003) relative to patients with 25-hydroxyvitamin D sufficiency. In addition, preadmission 25-hydroxyvitamin D deficiency is predictive of mortality. Patients with 25-hydroxyvitamin D insufficiency have an odds ratio for 30-day mortality of 1.60 (95% confidence interval 1.18-2.17; p = .003) and an adjusted odds ratio of 1.61 (95% confidence interval 1.06-1.57; p = .004) relative to patients with 25-hydroxyvitamin D sufficiency. CONCLUSION Deficiency of 25-hydroxyvitamin D prior to hospital admission is a significant predictor of acute kidney injury and mortality in a critically ill patient population.
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Tang JY, Fu T, Lau C, Oh DH, Bikle DD, Asgari MM. Vitamin D in cutaneous carcinogenesis: part I. J Am Acad Dermatol 2013; 67:803.e1-12, quiz 815-6. [PMID: 23062903 DOI: 10.1016/j.jaad.2012.05.044] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 04/27/2012] [Accepted: 05/02/2012] [Indexed: 02/07/2023]
Abstract
Skin cancer is the most common cancer in the United States. Exposure to ultraviolet radiation is a known risk factor for skin cancer but is also the principal means by which the body obtains vitamin D. Several studies have suggested that vitamin D plays a protective role in a variety of internal malignancies. With regard to skin cancer, epidemiologic and laboratory studies suggest that vitamin D and its metabolites may have a similar protective effect. These noncalcemic actions of vitamin D have called into question whether the current recommended intake of vitamin D is too low for optimal health and cancer prevention. Part I will review the role of vitamin D in the epidermis; part II will review the role of vitamin D in keratinocyte-derived tumors to help frame the discussion on the possible role of vitamin D in the prevention of skin cancer.
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Affiliation(s)
- Jean Y Tang
- Department of Dermatology, Stanford University, Stanford, CA 94305, USA.
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Bacchetta J, Sea JL, Chun RF, Lisse TS, Wesseling-Perry K, Gales B, Adams JS, Salusky IB, Hewison M. Fibroblast growth factor 23 inhibits extrarenal synthesis of 1,25-dihydroxyvitamin D in human monocytes. J Bone Miner Res 2013; 28:46-55. [PMID: 22886720 PMCID: PMC3511915 DOI: 10.1002/jbmr.1740] [Citation(s) in RCA: 143] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Revised: 07/10/2012] [Accepted: 08/02/2012] [Indexed: 01/03/2023]
Abstract
Vitamin D is a potent stimulator of monocyte innate immunity, and this effect is mediated via intracrine conversion of 25-hydroxyvitamin D (25OHD) to 1,25-dihydroxyvitamin D (1,25(OH)(2) D). In the kidney, synthesis of 1,25(OH)(2) D is suppressed by fibroblast growth factor 23 (FGF23), via transcriptional suppression of the vitamin D-activating enzyme 1α-hydroxylase (CYP27B1). We hypothesized that FGF23 also suppresses CYP27B1 in monocytes, with concomitant effects on intracrine responses to 1,25(OH)(2) D. Healthy donor peripheral blood mononuclear cell monocytes (PBMCm) and peritoneal dialysate monocyte (PDm) effluent from kidney disease patients were assessed at baseline to confirm the presence of mRNA for FGF23 receptors (FGFRs), with Klotho and FGFR1 being more strongly expressed than FGFR2/3/4 in both cell types. Immunohistochemistry showed coexpression of Klotho and FGFR1 in PBMCm and PDm, with this effect being enhanced following treatment with FGF23 in PBMCm but not PDm. Treatment with FGF23 activated mitogen-activated protein kinase (MAPK) and protein kinase B (Akt) pathways in PBMCm, demonstrating functional FGFR signaling in these cells. FGF23 treatment of PBMCm and PDm decreased expression of mRNA for CYP27B1. In PBMCm this was associated with downregulation of 25OHD to 1,25(OH)(2) D metabolism, and concomitant suppression of intracrine induced 24-hydroxylase (CYP24A1) and antibacterial cathelicidin (LL37). FGF23 suppression of CYP27B1 was particularly pronounced in PBMCm treated with interleukin-15 to stimulate synthesis of 1,25(OH)(2) D. These data indicate that FGF23 can inhibit extra-renal expression of CYP27B1 and subsequent intracrine responses to 1,25(OH)(2) D in two different human monocyte models. Elevated expression of FGF23 may therefore play a crucial role in defining immune responses to vitamin D and this, in turn, may be a key determinant of infection in patients with chronic kidney disease (CKD).
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Affiliation(s)
- Justine Bacchetta
- UCLA Orthopaedic Hospital, Department of Orthopaedic Surgery, Orthopedic Hospital Research Center, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, 90095, USA
- Department of Pediatrics, David Geffen School of Medicine, University of California at Los Angeles
| | - Jessica L Sea
- UCLA Orthopaedic Hospital, Department of Orthopaedic Surgery, Orthopedic Hospital Research Center, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, 90095, USA
| | - Rene F Chun
- UCLA Orthopaedic Hospital, Department of Orthopaedic Surgery, Orthopedic Hospital Research Center, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, 90095, USA
| | - Thomas S Lisse
- UCLA Orthopaedic Hospital, Department of Orthopaedic Surgery, Orthopedic Hospital Research Center, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, 90095, USA
| | | | - Barbara Gales
- Department of Pediatrics, David Geffen School of Medicine, University of California at Los Angeles
| | - John S. Adams
- UCLA Orthopaedic Hospital, Department of Orthopaedic Surgery, Orthopedic Hospital Research Center, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, 90095, USA
| | - Isidro B Salusky
- Department of Pediatrics, David Geffen School of Medicine, University of California at Los Angeles
| | - Martin Hewison
- UCLA Orthopaedic Hospital, Department of Orthopaedic Surgery, Orthopedic Hospital Research Center, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, 90095, USA
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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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1,25-Dihydroxyvitamin D fluctuations in cardiac surgery are related to age and clinical outcome*. Crit Care Med 2012; 40:2073-81. [PMID: 22584760 DOI: 10.1097/ccm.0b013e31824e8c42] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
OBJECTIVE To investigate the interrelationship between cardiac surgery, age, circulating concentrations of the vitamin D hormone 1,25-dihydroxyvitamin D, and clinical outcome. DESIGN Prospective, monocentric, two-arm parallel study. SETTING Tertiary Heart and Diabetes Center in the Federal State of North Rhine-Westphalia, Germany. PATIENTS Twenty-nine cardiac surgical patients aged ≤ 65 yrs and 30 patients ≥ 75 yrs. MEASUREMENTS We assessed 1,25-dihydroxyvitamin D and other biochemical parameters of mineral metabolism (calcium, phosphate, 25-hydroxyvitamin D, and parathyroid hormone), various inflammatory markers (C-reactive protein, interleukin-6 and 8), and different immunological parameters (CD4 and CD8 cells, monocyte HLA-DR expression). We collected blood samples preoperatively, immediately after surgery, and on postoperative days 1, 5, and 30. In addition, we assessed adverse outcome until discharge as a composite of myocardial infarction, low cardiac output syndrome, infection, stroke, or in-hospital death. RESULTS There were significant transient cardiac surgery-related fluctuations in 1,25-dihydroxyvitamin D and the aforementioned parameters of mineral metabolism, inflammation, and immune status. Compared to younger patients, older patients had consistently lower 1,25-dihydroxyvitamin D and phosphate levels (p = .013 and p = .036, respectively) and significantly higher interleukin 6 and 8 levels (p = .008 and p < .001, respectively). Circulating 1,25-dihydroxyvitamin D was directly related to glomerular filtration rate (R(2) = .227; p < .001) and inversely related to interleukin 6 (R(2) = .105; p = .012). The rate of adverse outcome tended to be higher in older than in younger patients (20.0% vs. 3.5%; p = .081). In risk score-adjusted logistic regression analysis, adverse outcome risk decreased by 7.7% (SE: 3.7%) for each pmol/L increment in 1,25-dihydroxyvitamin D (p = .037). CONCLUSIONS Circulating 1,25-dihydroxyvitamin D levels fluctuate in relation to cardiac surgery. Low 1,25-dihydroxyvitamin D levels are associated with inflammatory processes and age-related differences in clinical outcome. Future studies should determine whether therapies aimed at treating low 1,25-dihydroxyvitamin D levels can improve the outcome in older cardiac surgery patients.
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Khurana S, Bruggeman LA, Kao HY. Nuclear hormone receptors in podocytes. Cell Biosci 2012; 2:33. [PMID: 22995171 PMCID: PMC3543367 DOI: 10.1186/2045-3701-2-33] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Accepted: 08/10/2012] [Indexed: 11/14/2022] Open
Abstract
Nuclear receptors are a family of ligand-activated, DNA sequence-specific transcription factors that regulate various aspects of animal development, cell proliferation, differentiation, and homeostasis. The physiological roles of nuclear receptors and their ligands have been intensively studied in cancer and metabolic syndrome. However, their role in kidney diseases is still evolving, despite their ligands being used clinically to treat renal diseases for decades. This review will discuss the progress of our understanding of the role of nuclear receptors and their ligands in kidney physiology with emphasis on their roles in treating glomerular disorders and podocyte injury repair responses.
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Affiliation(s)
- Simran Khurana
- Department of Biochemistry, School of Medicine, Case Western Reserve University (CWRU) and the Comprehensive Cancer Center of CWRU, 10900 Euclid Avenue, Cleveland, Ohio 44106, USA.
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El Husseiny NM, Fahmy HM, Mohamed WA, Amin HH. Relationship between vitamin D and IL-23, IL-17 and macrophage chemoattractant protein-1 as markers of fibrosis in hepatitis C virus Egyptians. World J Hepatol 2012; 4:242-7. [PMID: 22993666 PMCID: PMC3443706 DOI: 10.4254/wjh.v4.i8.242] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2012] [Revised: 08/06/2012] [Accepted: 08/23/2012] [Indexed: 02/06/2023] Open
Abstract
AIM To assess vitamin D in hepatitis C patients and its relationship to interleukin (IL)-23, IL-17, and macrophage chemoattractant protein-1 (MCP-1). METHODS The study was conducted on 50 Egyptian hepatitis C virus (HCV) genotype number IV-infected patients and 25 age- and gender-matched healthy subjects. Venous blood samples were obtained. Samples were allowed to clot and sera were separated by centrifugation and stored at -20 °C. A 25 hydroxy vitamin D assay was carried out using solid phase RIA. A 1,25 dihydroxy vitamin D assay was carried out using a commercial kit purchased from Incstar Corporation. IL-17 and -23 and MCP-1 were assayed by an enzyme immunoassay. Quantitative and qualitative polymerase chain reaction for HCV virus were done by TaqMan technology. Only HCV genotype IV-infected subjects were included in the study. The mean ± SD were determined, a t-test for comparison of means of different parameters was used. Correlation analysis was done using Pearson's correlation. Differences among different groups were determined using the Kruskal-Wallis test. RESULTS The mean vitamin D level in HCV patients (group I) was 15 ± 5.2 ng/mL while in control (group II) was 39.7 ± 10.8. For active vitamin D in group I as 16.6 ± 4.8 ng/mL while in group II was 41.9 ± 7.9. IL-23 was 154 ± 97.8 in group I and 6.7 ± 2.17 in group II. IL-17 was 70.7 ± 72.5 in cases and 1.2 ± 0.4 in control. MCP-1 was 1582 ± 794.4 in group I and 216.1 ± 5.38 in group II. Vitamin D deficiency affected 72% of HCV-infected patients and 0% of the control group. Vitamin D insufficiency existed in 28% of HCV-infected patients and 12% of the control group. One hundred percent of the cirrhotic patients and 40% of non cirrhotic HCV-infected patients had vitamin D deficiency. IL-23, IL-17, and MCP-1 were markedly increased in HCV-infected patients in comparison to controls.A significant negative correlation between vitamin D and IL-17 and -23 and MCP-1 was detected. HCV-infected males and females showed no differences with respect to viral load, vitamin D levels, IL-17, IL-23 and MCP-1. The viral load was negatively correlated with vitamin D and active vitamin D (P = 0.0001 and P = 0.001, respectively), while positively correlated with IL-23, IL-17, and MCP-1. We classified the patients according to sonar findings into four groups. Group Ia with bright hepatomegaly and included 14 patients. Group Ib with perihepatic fibrosis and included 11 patients. Group Ic with liver cirrhosis and included 11 patients. Group Id with hepatocellular carcinoma (HCC) and included 14 patients. Vitamin D and active vitamin D were shown to be lower in cirrhotic patients and much lower in patients with HCC, and this difference was highly significant (P = 0.0001). IL-17 and -23 and MCP-1 were higher in advanced liver disease) and the differences were highly significant (P = 0.0001). CONCLUSION Whether the deficiency of vitamin D is related to HCV-induced chronic liver disease or predisposing factor for higher viral load is a matter of debate.
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Affiliation(s)
- Noha M El Husseiny
- Noha M El Husseiny, Hala M Fahmy, Internal Medicine Department, Faculty of Medicine, Cairo University, Cairo 11111, Egypt
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Chronic kidney disease and vascular remodelling: molecular mechanisms and clinical implications. Clin Sci (Lond) 2012; 123:399-416. [PMID: 22671427 DOI: 10.1042/cs20120074] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
CKD (chronic kidney disease) is a severe and complex disease with a very high prevalence of CV (cardiovascular) complications. CKD patients are exposed to haemodynamic disturbances in addition to severe metabolic abnormalities that lead to a specific form of arterial remodelling, which contributes to the development of CV disease. Arterial calcification is a major event in the arterial remodelling process and is strongly linked to mineral metabolism abnormalities associated with CKD. Arterial remodelling is not limited to arterial calcification and modifications in arterial wall composition are also observed. Activation of the RAS (renin-angiotensin system), ET-1 (endothelin-1), endothelial dysfunction, oxidative stress and ADMA (asymmetric ω-NG,NG-dimethylarginine), as well as the anti-aging molecule Klotho, are implicated in this process. The present review details the mechanisms involved in arterial calcification and arterial remodelling associated with CKD, and provides the clinical consequences of large and small artery stiffness and remodelling in CKD patients.
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Schaalan MF, Mohamed WA, Amin HH. Vitamin D deficiency: Correlation to interleukin-17, interleukin-23 and PIIINP in hepatitis C virus genotype 4. World J Gastroenterol 2012; 18:3738-44. [PMID: 22851868 PMCID: PMC3406428 DOI: 10.3748/wjg.v18.i28.3738] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 04/19/2012] [Accepted: 04/27/2012] [Indexed: 02/06/2023] Open
Abstract
AIM: To assess vitamin D (Vit D) abnormalities in hepatitis C infected patients and their relationship with interleukin (IL)-17, IL-23 and N-terminal propeptide of type III pro-collagen (PIIINP) as immune response mediators.
METHODS: The study was conducted on 50 Egyptian patients (36 male, 14 female) with hepatitis C virus (HCV) infection, who visited the Hepatology Outpatient Clinic in the Endemic Disease Hospital at Cairo University. Patients were compared with 25 age- and sex-matched healthy individuals. Inclusion criteria were based on a history of liver disease with HCV genotype 4 (HCV-4) infection (as new patients or under follow-up). Based on ultrasonography, patients were classified into four subgroups; 14 with bright hepatomegaly; 11 with perihepatic fibrosis; 11 with hepatic cirrhosis; and 14 with cirrhosis and hepatocellular carcinoma (HCC). Total Vit D (i.e., 25-OH-Vit D) and active Vit D [i.e., 1,25-(OH)2-Vit D] assays were carried out using commercial kits. IL-17, IL-23 and PIIINP levels were assayed using enzyme linked immunosorbent assay kits, while HCV virus was measured by quantitative and qualitative polymerase chain reaction.
RESULTS: Levels of Vit D and its active form were significantly lower in advanced liver disease (hepatic cirrhosis and/or carcinoma) patients, compared to those with bright hepatomegaly and perihepatic fibrosis. IL-17, IL-23 and PIIINP levels were markedly increased in HCV patients and correlated with the progression of hepatic damage. The decrease in Vit D and active Vit D was concomitant with an increase in viral load, as well as levels of IL-17, IL-23 and PIIINP among all subgroups of HCV-infected patients, compared to normal healthy controls. A significant negative correlation was evident between active Vit D and each of IL-17, IL-23 and PIIINP (r = -0.679, -0.801 and -0.920 at P < 0.001, respectively). HCV-infected men and women showed no differences with respect to Vit D levels. The viral load was negatively correlated with Vit D and active Vit D (r = -0.084 and -0.846 at P < 0.001, respectively), and positively correlated with IL-17, IL-23 and PIIINP (r = 0.951, 0.922 and 0.94 at P < 0.001, respectively). Whether the deficiency in Vit D was related to HCV-induced chronic liver disease or was a predisposing factor for a higher viral load remains to be elucidated.
CONCLUSION: The negative correlations between Vit D and IL-17, IL-23 and PIIINP highlight their involvement in the immune response in patients with HCV-4-related liver diseases in Egypt.
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Damasiewicz MJ, Magliano DJ, Daly RM, Gagnon C, Lu ZX, Ebeling PR, Chadban SJ, Atkins RC, Kerr PG, Shaw JE, Polkinghorne KR. 25-Hydroxyvitamin D levels and chronic kidney disease in the AusDiab (Australian Diabetes, Obesity and Lifestyle) study. BMC Nephrol 2012; 13:55. [PMID: 22759247 PMCID: PMC3441805 DOI: 10.1186/1471-2369-13-55] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 06/21/2012] [Indexed: 01/26/2023] Open
Abstract
Background Low 25-hydroxy vitamin D (25(OH)D) levels have been associated with an increased risk of albuminuria, however an association with glomerular filtration rate (GFR) is not clear. We explored the relationship between 25(OH)D levels and prevalent chronic kidney disease (CKD), albuminuria and impaired GFR, in a national, population-based cohort of Australian adults (AusDiab Study). Methods 10,732 adults ≥25 years of age participating in the baseline survey of the AusDiab study (1999–2000) were included. The GFR was estimated using an enzymatic creatinine assay and the CKD-EPI equation, with CKD defined as eGFR <60 ml/min/1.73 m2. Albuminuria was defined as a spot urine albumin to creatinine ratio (ACR) of ≥2.5 mg/mmol for men and ≥3.5 for women. Serum 25(OH)D levels of <50 nmol/L were considered vitamin D deficient. The associations between 25(OH)D level, albuminuria and impaired eGFR were estimated using multivariate regression models. Results 30.7% of the study population had a 25(OH)D level <50 nmol/L (95% CI 25.6-35.8). 25(OH)D deficiency was significantly associated with an impaired eGFR in the univariate model (OR 1.52, 95% CI 1.07-2.17), but not in the multivariate model (OR 0.95, 95% CI 0.67-1.35). 25(OH)D deficiency was significantly associated with albuminuria in the univariate (OR 2.05, 95% CI 1.58-2.67) and multivariate models (OR 1.54, 95% CI 1.14-2.07). Conclusions Vitamin D deficiency is common in this population, and 25(OH)D levels of <50 nmol/L were independently associated with albuminuria, but not with impaired eGFR. These associations warrant further exploration in prospective and interventional studies.
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Affiliation(s)
- Matthew J Damasiewicz
- Department of Nephrology, Monash Medical Centre, 246 Clayton Road, Clayton, 3168, Victoria, Australia.
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Vitamin D compounds and diabetic nephropathy. Arch Biochem Biophys 2012; 523:87-94. [DOI: 10.1016/j.abb.2012.02.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 02/08/2012] [Accepted: 02/13/2012] [Indexed: 12/22/2022]
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Birmingham DJ, Hebert LA, Song H, Noonan WT, Rovin BH, Nagaraja HN, Yu CY. Evidence that abnormally large seasonal declines in vitamin D status may trigger SLE flare in non-African Americans. Lupus 2012; 21:855-64. [PMID: 22433915 PMCID: PMC3839052 DOI: 10.1177/0961203312439640] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cross-sectional studies have shown that low vitamin D (25-hydroxyvitamin D (25(OH)D)) is associated with increased systemic lupus erythematosus (SLE) activity. This study is the first to assess the temporal relationship between 25(OH)D levels and onset of SLE flare. This assessment was made possible because of the specimen bank and database of the Ohio SLE Study (OSS), a longitudinal study of frequently relapsing SLE that involved regular bimonthly patient follow-up. We identified for this study 82 flares from 46 patients that were separated by at least 8 months from previous flares. Serum 25(OH)D levels were measured at 4 and 2 months before flare, and at the time of flare (a flare interval). We found that for flares occurring during low daylight months (LDM, Oct-Mar), 25(OH)D levels were decreased at the time of flare, but only in non-African American (non-AA) patients (32% decrease at flare, compared to 4 months prior, p < 0.001). To control for seasonal effects, we also measured 25(OH)D levels in the LDM "no-flare" intervals, which were intervals that matched to the same calendar months of the patients' LDM flare intervals, but that didn't end in flare (n = 24). For these matches, a significant decrease occurred in 25(OH)D levels during the flare intervals (18.1% decrease, p < 0.001), but not during the matching no-flare intervals (6.2% decrease, p = 0.411). For flares occurring during high daylight months (HDM), 25(OH)D levels changed only in non-AA patients, increasing slightly (5.6%, p = 0.010). Analysis of flare rates for the entire OSS cohort (n = 201 flares) revealed a tendency for higher flare rates during LDM compared to HDM, but again only in non-AA patients (p = 0.060). Flare rates were lower during HDM for non-AA patients compared to AA patients (p = 0.028). In conclusion, in non-AA SLE patients, unusually large declines in 25(OH)D during LDM may be mechanistically related to SLE flare, whereas relatively high 25(OH)D levels during HDM may protect against flare.
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Affiliation(s)
- D J Birmingham
- Department of Medicine and Davis Heart and Lung Research Institute, Ohio State University Medical Center, Columbus, OH 43210, USA.
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The serum 24,25-dihydroxyvitamin D concentration, a marker of vitamin D catabolism, is reduced in chronic kidney disease. Kidney Int 2012; 82:693-700. [PMID: 22648296 PMCID: PMC3434313 DOI: 10.1038/ki.2012.193] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Chronic kidney disease is characterized, in part, as a state of decreased production of 1,25-dihydroxyvitamin D (1,25(OH)(2)D); however, this paradigm overlooks the role of vitamin D catabolism. We developed a mass spectrometric assay to quantify serum concentration of 24,25-dihydroxyvitamin D (24,25(OH)(2)D), the first metabolic product of 25-hydroxyvitamin D (25(OH)D) by CYP24A1, and determined its clinical correlates and associated outcomes among 278 participants with chronic kidney disease in the Seattle Kidney Study. For eGFRs of 60 or more, 45-59, 30-44, 15-29, and under 15 ml/min per 1.73 m(2), the mean serum 24,25(OH)(2)D concentrations significantly trended lower from 3.6, 3.2, 2.6, 2.6, to 1.7 ng/ml, respectively. Non-Hispanic black race, diabetes, albuminuria, and lower serum bicarbonate were also independently and significantly associated with lower 24,25(OH)(2)D concentrations. The 24,25(OH)(2)D concentration was more strongly correlated with that of parathyroid hormone than was 25(OH)D or 1,25(OH)(2)D. A 24,25(OH)(2)D concentration below the median was associated with increased risk of mortality in unadjusted analysis, but this was attenuated with adjustment for potential confounding variables. Thus, chronic kidney disease is a state of stagnant vitamin D metabolism characterized by decreases in both 1,25(OH)(2)D production and vitamin D catabolism.
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Abstract
PURPOSE OF REVIEW Great progress has been made in recent years in understanding the expanding roles of the vitamin D endocrine system beyond calcemic regulation, including pathophysiological actions in the kidney and the cardiovascular system. The purpose of this review is to update the recent advance regarding the effects of vitamin D and its analogs on the renal and cardiovascular system. RECENT FINDINGS Vitamin D deficiency is not only widely associated with chronic kidney disease and cardiovascular disease in humans, but may also accelerate the disease progression. Dysregulation of vitamin D metabolism caused by renal insufficiency contributes to the low vitamin D status. Preclinical and clinical studies have demonstrated impressive therapeutic outcome with low-calcemic vitamin D analogs in renal and cardiovascular disease. The mechanism underlying the renal and cardiovascular protection involves regulation of multiple signaling pathways by vitamin D including nuclear factor κB, Wnt/β-catenin and the renin-angiotensin system. SUMMARY The renal and cardiovascular protective activity of vitamin D revealed in recent studies has profound clinical implications. Nutritional correction of vitamin D deficiency and treatment with vitamin D analogs could be therapeutic options for renal and cardiovascular problems. New vitamin D analogs with better renal and cardiovascular therapeutic efficacy are highly desired. More randomized trials are needed to address these issues.
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Vitamin D deficiency and persistent proteinuria among HIV-infected and uninfected injection drug users. AIDS 2012; 26:295-302. [PMID: 22156964 DOI: 10.1097/qad.0b013e32834f33a2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE Proteinuria occurs commonly among HIV-infected and uninfected injection drug users (IDUs) and is associated with increased mortality risk. Vitamin D deficiency, highly prevalent among IDUs and potentially modifiable, may contribute to proteinuria. To determine whether vitamin D is associated with proteinuria in this population, we conducted a cross-sectional study in the AIDS Linked to the IntraVenous Experience (ALIVE) Study. METHODS 25(OH)-vitamin D levels were measured in 268 HIV-infected and 614 HIV-uninfected participants. The association between vitamin D deficiency (<10 ng/ml) and urinary protein excretion was evaluated by linear regression. The odds of persistent proteinuria (urine protein-to-creatinine ratio >200 mg/g on two occasions) associated with vitamin D deficiency was examined using logistic regression. RESULTS One-third of participants were vitamin D-deficient. Vitamin D deficiency was independently associated with higher urinary protein excretion (P < 0.05) among HIV-infected and diabetic IDUs (P-interaction < 0.05 for all). Persistent proteinuria occurred in 18% of participants. Vitamin D deficiency was associated with greater than six-fold odds of persistent proteinuria among diabetic IDUs [odds ratio (OR) 6.29, 95% confidence interval (CI) 1.54, 25.69] independent of sociodemographic characteristics, comorbid conditions, body mass index, and impaired kidney function [estimated glomerular filtration rate (eGFR) <60 ml/min per 1.73 m(2)]; no association, however, was observed among nondiabetic IDUs (OR 1.06, 95% CI 0.64, 1.76) (P-interaction <0.05). CONCLUSIONS Vitamin D deficiency was associated with higher urinary protein excretion among those with HIV infection and diabetes. Vitamin D deficiency was independently associated with persistent proteinuria among diabetic IDUs, although not in nondiabetic persons. Whether vitamin D repletion ameliorates proteinuria in these patients requires further study.
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Joergensen C, Reinhard H, Schmedes A, Hansen PR, Wiinberg N, Petersen CL, Winther K, Parving HH, Jacobsen PK, Rossing P. Vitamin D levels and asymptomatic coronary artery disease in type 2 diabetic patients with elevated urinary albumin excretion rate. Diabetes Care 2012; 35:168-72. [PMID: 22040839 PMCID: PMC3241314 DOI: 10.2337/dc11-1372] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Coronary artery disease (CAD) is the major cause of morbidity and mortality in type 2 diabetic patients. Severe vitamin D deficiency has been shown to predict cardiovascular mortality in type 2 diabetic patients. RESEARCH DESIGN AND METHODS We investigated the association among severe vitamin D deficiency, coronary calcium score (CCS), and asymptomatic CAD in type 2 diabetic patients with elevated urinary albumin excretion rate (UAER) >30 mg/24 h. This was a cross-sectional study including 200 type 2 diabetic patients without a history of CAD. Severe vitamin D deficiency was defined as plasma 25-hydroxyvitamin D (p-25[OH]D3) <12.5 nmol/L. Patients with plasma N-terminal pro-brain natriuretic peptide >45.2 ng/L or CCS ≥400 were stratified as being high risk for CAD (n= 133). High-risk patients were examined by myocardial perfusion imaging (MPI; n = 109), computed tomography angiography (n = 20), or coronary angiography (CAG; n = 86). Patients' p-25(OH)D3 levels were determined by high-performance liquid chromatography/tandem mass spectrometry. RESULTS The median (range) vitamin D level was 36.9 (3.8-118.6) nmol/L. The prevalence of severe vitamin D deficiency was 9.5% (19/200). MPI or CAG demonstrated significant CAD in 70 patients (35%). The prevalence of CCS ≥400 was 34% (68/200). Severe vitamin D deficiency was associated with CCS ≥400 (odds ratio [OR] 4.3, 95% CI [1.5-12.1], P = 0.005). This association persisted after adjusting for risk factors (4.6, 1.5-13.9, P = 0.007). Furthermore, severe vitamin D deficiency was associated with asymptomatic CAD (adjusted OR 2.9, 1.02-7.66, P = 0.047). CONCLUSIONS In high-risk type 2 diabetic patients with elevated UAER, low levels of vitamin D are associated with asymptomatic CAD.
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Bischoff-Ferrari HA, Dawson-Hughes B, Stöcklin E, Sidelnikov E, Willett WC, Edel JO, Stähelin HB, Wolfram S, Jetter A, Schwager J, Henschkowski J, von Eckardstein A, Egli A. Oral supplementation with 25(OH)D3 versus vitamin D3: effects on 25(OH)D levels, lower extremity function, blood pressure, and markers of innate immunity. J Bone Miner Res 2012; 27:160-9. [PMID: 22028071 DOI: 10.1002/jbmr.551] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 09/11/2011] [Accepted: 09/22/2011] [Indexed: 01/06/2023]
Abstract
To test the effect of 25(OH)D(3) (HyD) compared to vitamin D(3) on serum 25-hydroxyvitamin D levels (25(OH)D), lower extremity function, blood pressure, and markers of innate immunity. Twenty healthy postmenopausal women with an average 25(OH)D level of 13.2 ± 3.9 ng/mL (mean ± SD) and a mean age of 61.5 ± 7.2 years were randomized to either 20 µg of HyD or 20 µg (800 IU) of vitamin D(3) per day in a double-blind manner. We measured on 14 visits over 4 months, 25(OH)D serum levels, blood pressure, and seven markers of innate immunity (eotaxin, interleukin [IL]-8, IL-12, interferon gamma-induced protein 10 kDa [IP-10], monocyte chemotactic protein-1 [MCP-1], macrophage inflammatory protein beta [MIP-1β], and "Regulated upon Activation, Normal T-cell Expressed, and Secreted" [RANTES]). At baseline and at 4 months, a test battery for lower extremity function (knee extensor and flexor strength, timed up and go, repeated sit-to-stand) was assessed. All analyses were adjusted for baseline measurement, age, and body mass index. Mean 25(OH)D levels increased to 69.5 ng/mL in the HyD group. This rise was immediate and sustained. Mean 25(OH)D levels increased to 31.0 ng/mL with a slow increase in the vitamin D(3) group. Women on HyD compared with vitamin D(3) had a 2.8-fold increased odds of maintained or improved lower extremity function (odds ratio [OR] = 2.79; 95% confidence interval [CI], 1.18-6.58), and a 5.7-mmHg decrease in systolic blood pressure (p = 0.0002). Both types of vitamin D contributed to a decrease in five out of seven markers of innate immunity, significantly more pronounced with HyD for eotaxin, IL-12, MCP-1, and MIP-1 β. There were no cases of hypercalcemia at any time point. Twenty micrograms (20 µg) of HyD per day resulted in a safe, immediate, and sustained increase in 25(OH)D serum levels in all participants, which may explain its significant benefit on lower extremity function, systolic blood pressure, and innate immune response compared with vitamin D(3).
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Echida Y, Mochizuki T, Uchida K, Tsuchiya K, Nitta K. Risk factors for vitamin D deficiency in patients with chronic kidney disease. Intern Med 2012; 51:845-50. [PMID: 22504237 DOI: 10.2169/internalmedicine.51.6897] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
OBJECTIVE We conducted a cohort study to identify the risk factors for vitamin D deficiency in predialyzed patients with chronic kidney disease (CKD). METHODS An observational study of 135 outpatients with stage 3-5 CKD was undertaken. Clinical and biochemical parameters were analyzed in terms of nutritional status, inflammation, and mineral metabolism in relation to serum levels of 25-hydroxyvitamin D [25(OH)D]. Levels of 25(OH)D lower than 15 ng/mL were considered to be deficient. RESULTS The 25(OH)D-deficient group had a higher body mass index (24.1±4.2 kg/m(2) vs. 22.5±4.0 kg/m(2), p=0.0322), and had more diabetic patients (27.9% vs. 3.6%, p=0.0003). The multivariate analysis revealed that body mass index (odds ratio=2.758; 95% CI, 1.048-7.721; p=0.0398), the presence of diabetes (odds ratio=7.792; 95% CI, 1.808-55.439; p=0.0043), lower hemoglobin concentration (odds ratio=0.297; 95% CI, 0.099-8.732; p=0.821), higher serum levels of non-HDL cholesterol (odds ratio=3.570; 95% CI, 1.449-9.442; p=0.0053) and triglyceride (odds ratio=2.447; 95% CI, 0.779-1.776; p=0.0258) were the factors associated with low 25(OH)D levels. CONCLUSION Vitamin D deficiency was common among the predialysis CKD patients, and the factors identified as being associated with vitamin D deficiency were diabetes and obesity.
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Affiliation(s)
- Yoshihisa Echida
- Department of Medicine, Kidney Center, Tokyo Women's Medical University, Japan
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Vitamin D deficiency is common in children and adolescents with chronic kidney disease. Kidney Int 2011; 81:690-7. [PMID: 22205356 DOI: 10.1038/ki.2011.431] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Here we determined if vitamin D deficiency is more common in children with chronic kidney disease compared to healthy children. In addition, we sought to identify disease-specific risk factors for this deficiency, as well as its metabolic consequences. We found that nearly half of 182 patients (ages 5 to 21) with kidney disease (stages 2 to 5) and a third of age-matched 276 healthy children were 25-hydroxyvitamin D deficient (<20 ng/ml). The risk of deficiency was significantly greater in advanced disease. Focal segmental glomerulosclerosis and low albumin were significantly associated with lower 25-hydroxyvitamin D, which, in turn, was associated with significantly higher intact parathyroid hormone levels. We found that 25-hydroxyvitamin D levels were positively associated with 1,25-dihydroxyvitamin D, the relationship being greatest in advanced disease (significant interaction), and inversely related to those of inflammatory markers C-reactive protein and IL-6. The association with C-reactive protein persisted when adjusted for the severity of kidney disease. Thus, lower 25-hydroxyvitamin D may contribute to hyperparathyroidism, inflammation, and lower 1,25-dihydroxyvitamin D in children and adolescents, especially those with advanced kidney disease.
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Yokote S, Yokoo T, Matsumoto K, Ohkido I, Utsunomiya Y, Kawamura T, Hosoya T. Metanephros transplantation inhibits the progression of vascular calcification in rats with adenine-induced renal failure. Nephron Clin Pract 2011; 120:e32-40. [PMID: 22205150 DOI: 10.1159/000332012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Accepted: 08/15/2011] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND/AIM Recent research has shown that transplanted metanephroi form primitive vascularized kidneys with histologically recognizable renal features. The aim of the present study was to determine the metabolic function of transplanted metanephroi in rats with chronic renal failure (CRF), with particular reference to secondary hyperparathyroidism and vascular calcification. METHODS CRF was induced in 11-week-old male Wistar rats by maintaining them on a 0.75% adenine diet for 4 weeks, followed by normal diet for an additional 2 weeks. At the end of adenine loading, whole metanephroi from embryonic day 15 rats were transplanted into the omentum and epididymis of the transplantation group. Vascular calcification was evaluated 2 weeks after metanephroi transplantation. RESULTS Metanephros transplantation significantly reduced vascular calcium and phosphorus content and suppressed the progression of vascular calcification as indicated by von Kossa staining of the media of the thoracic aorta. However, no significant differences between the adenine-fed control and transplantation groups were found regarding the serum levels of 1,25(OH)2D3, calcium or phosphorus or the calcium × phosphorus product. CONCLUSION The present study has shown that transplantation of metanephroi suppresses the progression of vascular calcification via a mechanism that is independent of calcium-phosphorus dynamics.
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Affiliation(s)
- Shinya Yokote
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
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Jones G, Prosser DE, Kaufmann M. 25-Hydroxyvitamin D-24-hydroxylase (CYP24A1): its important role in the degradation of vitamin D. Arch Biochem Biophys 2011; 523:9-18. [PMID: 22100522 DOI: 10.1016/j.abb.2011.11.003] [Citation(s) in RCA: 339] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 10/19/2011] [Accepted: 11/01/2011] [Indexed: 01/08/2023]
Abstract
CYP24A1 is the cytochrome P450 component of the 25-hydroxyvitamin D(3)-24-hydroxylase enzyme that catalyzes the conversion of 25-hydroxyvitamin D(3) (25-OH-D(3)) and 1,25-dihydroxyvitamin D(3) (1,25-(OH)(2)D(3)) into 24-hydroxylated products, which constitute the degradation of the vitamin D molecule. This review focuses on recent data in the CYP24A1 field, including biochemical, physiological and clinical developments. Notable among these are: the first crystal structure for rat CYP24A1; mutagenesis studies which change the regioselectivity of the enzyme; and the finding that natural inactivating mutations of CYP24A1 cause the genetic disease idiopathic infantile hypercalcemia (IIH). The review also discusses the emerging correlation between rising serum phosphate/FGF-23 levels and increased CYP24A1 expression in chronic kidney disease, which in turn underlies accelerated degradation of both serum 25-OH-D(3) and 1,25-(OH)(2)D(3) in this condition. This review concludes by evaluating the potential clinical utility of blocking this enzyme with CYP24A1 inhibitors in various disease states.
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Affiliation(s)
- Glenville Jones
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada K7L 3N6.
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Guerrero F, Montes de Oca A, Aguilera-Tejero E, Zafra R, Rodriguez M, Lopez I. The effect of vitamin D derivatives on vascular calcification associated with inflammation. Nephrol Dial Transplant 2011; 27:2206-12. [DOI: 10.1093/ndt/gfr555] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
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Liu LJ, Lv JC, Shi SF, Chen YQ, Zhang H, Wang HY. Oral calcitriol for reduction of proteinuria in patients with IgA nephropathy: a randomized controlled trial. Am J Kidney Dis 2011; 59:67-74. [PMID: 22019331 DOI: 10.1053/j.ajkd.2011.09.014] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Accepted: 09/05/2011] [Indexed: 11/11/2022]
Abstract
BACKGROUND Vitamin D has shown efficacy in the reduction of proteinuria in patients with chronic kidney disease. This study aimed to determine the effect of calcitriol on urinary protein excretion in patients with immunoglobulin A (IgA) nephropathy. STUDY DESIGN Open-label, non-placebo-controlled, randomized study. SETTING & PARTICIPANTS 50 patients with IgA nephropathy were enrolled. The main criterion for inclusion was urinary protein excretion >0.8 g/d after renin-angiotensin system-inhibitor treatment for at least 3 months. INTERVENTION Patients were randomly assigned (1:1) to receive 2 doses (0.5 μg) of calcitriol per week or no treatment for 48 weeks. OUTCOMES The primary end point was to compare change in 24-hour urinary protein excretion from baseline to last measurement during treatment. MEASUREMENTS Every 8 weeks, there was measurement of 24-hour urinary protein excretion, serum calcium, serum phosphorus, serum creatinine, and intact parathyroid hormone. RESULTS Measurement of the primary end point showed changes in urinary protein excretion of +21% (from 1.29 to 1.58 g/24 h; 95% CI, -9% to +52%) in the control group and -19% (from 1.60 to 1.30 g/24 h; 95% CI, -42% to +4%) in the calcitriol-treated group. There was a significant decrease in proteinuria in the calcitriol-treated group compared with the control group (difference between groups, 41%; 95% CI, 5%-79%; P = 0.03). The secondary end point of achieving at least a 15% decrease in proteinuria was attained by 7 of 24 (29%) controls and 17 of 26 (65%) of those treated with calcitriol (P = 0.02). No significant differences were observed in decrease in estimated glomerular filtration rate and change in blood pressure between the 2 groups. The incidence of recorded adverse events was similar between the 2 groups. LIMITATIONS Small and non-placebo-controlled study. CONCLUSIONS The addition of calcitriol to a renin-angiotensin system inhibitor resulted in a safe decrease in proteinuria in patients with IgA nephropathy.
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Affiliation(s)
- Li-Jun Liu
- Renal Division, Peking University First Hospital, Institute of Nephrology, Peking University, Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, PR China
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Abstract
PURPOSE OF REVIEW Patients with chronic renal disease have elevated serum phosphate levels, elevated fibroblast-like growth factor 23 (FGF-23), and declining vitamin D status. These changes are related and may be responsible for elevated 25-hydroxyvitamin D-24-hydroxylase (CYP24A1) and dysfunctional vitamin D metabolism. This review focuses on the biochemistry and pathophysiology of CYP24A1 and the utility of blocking this enzyme with CYP24A1 inhibitors in chronic kidney disease (CKD) patients. RECENT FINDINGS CYP24A1 is the cytochrome P450 enzyme that catalyzes the conversion of 25-hydroxyvitamin D3 (25-OHD3) and its hormonal form, 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3], into 24-hydroxylated products targeted for excretion. The CYP24A1-null phenotype is consistent with the catabolic role of CYP24A1. A number of polymorphisms of CYP24A1 have recently been identified. New data from the uremic rat and humans suggest that dysfunctional vitamin D metabolism is due to changes in CYP24A1 expression caused by phosphate and FGF-23 elevations. SUMMARY Changes in serum phosphate and FGF-23 levels in the CKD patient increase CYP24A1 expression resulting in decreased vitamin D status. Vitamin D deficiency may exacerbate defective calcium and phosphate homeostasis causing renal osteodystrophy and contribute to the other complications of renal disease. These findings argue for increased focus on correcting vitamin D deficiency in CKD patients by blocking CYP24A1 activity.
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Affiliation(s)
- Martin Petkovich
- Division of Cancer Biology and Genetics, Cancer Research Institute, Department of Biochemistry, Queen's University, Kingston, Ontario, Canada.
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de Boer IH, Katz R, Chonchol M, Ix JH, Sarnak MJ, Shlipak MG, Siscovick DS, Kestenbaum B. Serum 25-hydroxyvitamin D and change in estimated glomerular filtration rate. Clin J Am Soc Nephrol 2011; 6:2141-9. [PMID: 21836148 DOI: 10.2215/cjn.02640311] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND AND OBJECTIVES Mounting evidence suggests that 1,25-dihydroxyvitamin D prevents the progression of chronic kidney disease (CKD). It is not clear whether "nutritional" forms of vitamin D affect GFR. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We tested whether serum 25-hydroxyvitamin D concentration (25(OH)D), a measure of total vitamin D intake from cutaneous synthesis and dietary consumption, is associated with loss of estimated GFR among 1705 older adults with predominantly normal baseline kidney function participating in the Cardiovascular Health Study. Baseline 25(OH)D was measured by HPLC-tandem mass spectrometry. GFR was estimated at baseline and 4 years later using the CKD-EPI formula, with rapid GFR loss defined as 12 ml/min per 1.73 m(2) or more over 4 years. RESULTS Rapid GFR loss was observed for 207 participants (12%). Each 10 ng/ml lower 25(OH)D was associated with a 25% greater risk of rapid GFR loss (95% confidence interval [CI] 5%, 49%, P = 0.01), adjusting for potential confounding characteristics. Compared with 25(OH)D ≥30 ng/ml, 25(OH)D concentrations 15 to 29 ng/ml and <15 ng/ml were associated with 29% (95% CI -13%, 91%) and 68% (95% CI 1%, 177%) greater adjusted risks of rapid GFR loss, respectively. Magnitudes of association were largest among participants with diabetes. RESULTS were similar evaluating a composite outcome of rapid GFR loss, end stage renal disease, and death. Conclusions Insufficient 25(OH)D may be a modifiable risk factor for early GFR loss. We recommend clinical trials to determine whether vitamin D supplementation prevents the development and progression of CKD.
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Affiliation(s)
- Ian H de Boer
- Department of Medicine, University of Washington, Seattle, WA 98195, USA. Tele
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81
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Oral cholecalciferol decreases albuminuria and urinary TGF-β1 in patients with type 2 diabetic nephropathy on established renin-angiotensin-aldosterone system inhibition. Kidney Int 2011; 80:851-60. [PMID: 21832985 DOI: 10.1038/ki.2011.224] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The anti-inflammatory, antifibrotic, and antiproteinuric properties of vitamin D have been defined in studies using active vitamin D analogs. In this prospective observational study we determined whether nutritional vitamin D repletion can have additional beneficial effects in patients with type 2 diabetic nephropathy already established on renin-angiotensin-aldosterone system inhibition. During a 7-month period, 63 patients were enrolled and those with low levels of 25(OH)D were treated with oral cholecalciferol for 4 months. Baseline serum 25(OH)D and 1,25(OH)(2)D showed no significant correlation with baseline urinary MCP-1, TGF-β1, or albuminuria measured as the urinary albumin-to-creatinine ratio. Of the 63 patients, 54 had insufficient or deficient levels of serum 25(OH)D and 49 complied with cholecalciferol therapy and follow-up. Both 25(OH)D and 1,25(OH)(2)D were significantly increased at 2 and 4 months of treatment. Albuminuria and urinary TGF-β1 decreased significantly at both time points compared to their baseline values, while urinary MCP-1 did not change. Thus, in the short term, dietary vitamin D repletion with cholecalciferol had a beneficial effect in delaying the progression of diabetic nephropathy above that due to established renin-angiotensin-aldosterone system inhibition.
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82
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Navaneethan SD, Schold JD, Arrigain S, Jolly SE, Jain A, Schreiber MJ, Simon JF, Srinivas TR, Nally JV. Low 25-hydroxyvitamin D levels and mortality in non-dialysis-dependent CKD. Am J Kidney Dis 2011; 58:536-43. [PMID: 21816525 DOI: 10.1053/j.ajkd.2011.04.028] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Accepted: 04/26/2011] [Indexed: 02/06/2023]
Abstract
BACKGROUND Low 25-hydroxyvitamin D (25[OH]D) levels are common in patients with non-dialysis-dependent chronic kidney disease (CKD). The associations between low 25(OH)D levels and mortality in non-dialysis-dependent patients with CKD are unclear. STUDY DESIGN Retrospective cohort study. SETTING & PARTICIPANTS Patients with stages 3-4 CKD (estimated glomerular filtration rate, 15-59 mL/min/1.73 m(2); n = 12,673) who had 25(OH)D levels measured after the diagnosis of CKD in the Cleveland Clinic Health System. PREDICTOR 25(OH)D levels categorized into 3 groups: <15, 15-29, and ≥30 ng/mL. OUTCOMES We examined factors associated with low 25(OH)D levels and associations between low 25(OH)D levels and all-cause mortality (ascertained using the Social Security Death Index and our electronic medical record) using logistic regression, Cox proportional hazard models, and Kaplan-Meier survival curves. MEASUREMENTS 25(OH)D was measured using chemiluminescence immunoassay. RESULTS Of 12,763 patients with CKD, 15% (n = 1,970) had 25(OH)D levels <15 ng/mL, whereas 45% (n = 5,749) had 25(OH)D levels of 15-29 ng/mL. Male sex, African American race, diabetes, coronary artery disease, and lower estimated glomerular filtration rate were associated significantly with 25(OH)D level <30 ng/mL. A graded increase in risk of 25(OH)D level <30 ng/mL was evident across increasing body mass index levels. Patients who had 25(OH)D levels measured in fall through spring had higher odds for 25(OH)D levels <30 ng/mL. After covariate adjustment, patients with CKD with 25(OH)D levels <15 ng/mL had a 33% increased risk of mortality (95% CI, 1.07-1.65). The group with 25(OH)D levels of 15-29 ng/mL did not show a significantly increased risk of mortality (HR, 1.03; 95% CI, 0.86-1.22) compared with patients with 25(OH)D levels ≥30 ng/mL. LIMITATIONS Single-center observational study, lack of data for albuminuria and other markers of bone and mineral disorders, and attrition bias. CONCLUSIONS 25(OH)D level <15 ng/mL was associated independently with all-cause mortality in non-dialysis-dependent patients with CKD.
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Affiliation(s)
- Sankar D Navaneethan
- Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute, Cleveland, OH 44195, USA.
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83
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Lorente-Cebrián S, Eriksson A, Dunlop T, Mejhert N, Dahlman I, Aström G, Sjölin E, Wåhlén K, Carlberg C, Laurencikiene J, Hedén P, Arner P, Rydén M. Differential effects of 1α,25-dihydroxycholecalciferol on MCP-1 and adiponectin production in human white adipocytes. Eur J Nutr 2011; 51:335-42. [PMID: 21701898 DOI: 10.1007/s00394-011-0218-z] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Accepted: 06/06/2011] [Indexed: 12/15/2022]
Abstract
BACKGROUND/AIM Obesity is characterized by a low-grade inflammation in white adipose tissue (WAT), which promotes insulin resistance. Low serum levels of 1α,25-dihydroxycholecalciferol (DHCC) associate with insulin resistance and higher body mass index although it is unclear whether vitamin D supplementation improves insulin sensitivity. We investigated the effects of DHCC on adipokine gene expression and secretion in adipocytes focusing on two key factors with pro-inflammatory [monocyte chemoattractant protein-1 (MCP-1/CCL2)] and anti-inflammatory [adiponectin (ADIPOQ)] effects. METHODS Pre-adipocytes were isolated from human subcutaneous WAT and cultured until full differentiation. Differentiated adipocytes were either pre-treated with DHCC (10(-7) M) and subsequently incubated with tumor necrosis factor-α (TNFα, 100 ng/mL) or concomitantly incubated with TNFα/DHCC. MCP1 and adiponectin mRNA expression was measured by RT-PCR and protein release by ELISA. RESULTS DHCC was not toxic and did not affect adipocyte morphology or the mRNA levels of adipocyte-specific genes. TNFα induced a significant increase in CCL2 mRNA and protein secretion, while DHCC alone reduced CCL2 mRNA expression (~25%, p < 0.05). DHCC attenuated TNFα-induced CCL2 mRNA expression in both pre-incubation (~15%, p < 0.05) and concomitant (~60%, p < 0.01) treatments. TNFα reduced ADIPOQ mRNA (~80%) and secretion (~35%). DHCC alone decreased adiponectin secretion to a similar degree (~35%, p < 0.05). Concomitant treatment with DHCC/TNFα for 48 h had an additive effect, resulting in a pronounced reduction in adiponectin secretion (~70%). CONCLUSIONS DHCC attenuates MCP-1 and adiponectin production in human adipocytes, thereby reducing the expression of both pro- and anti-inflammatory factors. These effects may explain the difficulties so far in determining the role of DHCC in insulin sensitivity and obesity in humans.
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Affiliation(s)
- Silvia Lorente-Cebrián
- Department of Medicine Huddinge, Lipid Laboratory, Karolinska Institutet, NVS, Karolinska University Hospital Huddinge, 141 86, Stockholm, Sweden.
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84
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Yang L, Brozovic S, Xu J, Long Y, Kralik PM, Waigel S, Zacharias W, Zheng S, Epstein PN. Inflammatory gene expression in OVE26 diabetic kidney during the development of nephropathy. Nephron Clin Pract 2011; 119:e8-20. [PMID: 21606656 DOI: 10.1159/000324407] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Accepted: 01/12/2011] [Indexed: 11/19/2022] Open
Abstract
AIM To define renal gene expression during the development of severe albuminuria in OVE26 diabetic mice. METHODS Kidney microarray analysis was performed at 2, 4 and 8 months. Data were validated by RT-PCR, in situ hybridization and immunohistochemistry. RESULTS Gene expression differences between control and diabetic mice increased 10-fold from 2 to 8 months. This change was most obvious for inflammatory genes. Three inflammatory genes, complement C3, VCAM1 and CD44 were upregulated more than 4-fold. Inflammatory gene expression correlated with albuminuria and C3 and CD44 increased in tubules that accumulated albumin. VCAM1 was induced in different tubules that were neither dilated nor accumulated albumin. Six of 8 genes previously reported to be markers of human advanced diabetic nephropathy and the NF-κB_IFN_x promoter module were elevated in the oldest diabetic mice. Vitamin D inhibits diabetic renal inflammation. Vitamin D and mRNA for vitamin D synthetic enzyme CYP2B1 were elevated in kidneys of young OVE26 mice. CONCLUSIONS OVE26 mice induce inflammatory genes consistent with advanced renal disease, associated with severe albuminuria and to a greater extent than reported in other diabetic models. They provide an excellent model of diabetic nephropathy to assess the effect of induction of inflammatory proteins.
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Affiliation(s)
- Lu Yang
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, USA
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85
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Joergensen C, Hovind P, Schmedes A, Parving HH, Rossing P. Vitamin D levels, microvascular complications, and mortality in type 1 diabetes. Diabetes Care 2011; 34:1081-5. [PMID: 21525501 PMCID: PMC3114500 DOI: 10.2337/dc10-2459] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To evaluate vitamin D as a predictor of all-cause mortality, progression from normoalbuminuria to micro- or macroalbuminuria, and the development of background or proliferative retinopathy in patients with type 1 diabetes. RESEARCH DESIGN AND METHODS A prospective observational follow-up study in which an inception cohort of type 1 diabetic patients was followed from onset of diabetes diagnosed between 1979 and 1984. Plasma vitamin D [25(OH)D3] levels were determined by high performance liquid chromatography/tandem mass spectrometry in 227 patients before the patients developed microalbuminuria. Values equal to or below the 10% percentile (15.5 nmol/L) were considered severe vitamin D deficiency. RESULTS Median (range) vitamin D was 44.6 (1.7-161.7) nmol/L. Vitamin D level was not associated with age, sex, urinary albumin excretion rate (UAER), or blood pressure. During follow-up, 44 (18%) patients died. In a Cox proportional hazards model, the hazard ratio for mortality in subjects with severe vitamin D deficiency was 2.7 (1.1-6.7), P = 0.03, after adjustment for UAER, HbA(1c), and conventional cardiovascular risk factors (age, sex, blood pressure, cholesterol, smoking). Of the 220 patients, 81 (37%) developed microalbuminuria and 27 (12%) of these progressed to macroalbuminuria. Furthermore, 192 (87%) patients developed background retinopathy, whereas 34 (15%) progressed to proliferative retinopathy. Severe vitamin D deficiency at baseline did not predict the development of these microvascular complications. CONCLUSIONS In patients with type 1 diabetes, severe vitamin D deficiency independently predicts all-cause mortality but not development of microvascular complications in the eye and kidney. Whether vitamin D substitution in type 1 diabetic patients can improve the prognosis remains to be investigated.
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86
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Prunotto M, Gabbiani G, Pomposiello S, Ghiggeri G, Moll S. The kidney as a target organ in pharmaceutical research. Drug Discov Today 2011; 16:244-59. [DOI: 10.1016/j.drudis.2010.11.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 11/11/2010] [Accepted: 11/24/2010] [Indexed: 02/07/2023]
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87
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Timpini A, Pini L, Tantucci C, Cossi S, Grassi V. Vitamin D and health status in elderly. Intern Emerg Med 2011; 6:11-21. [PMID: 20517656 DOI: 10.1007/s11739-010-0407-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Accepted: 04/27/2010] [Indexed: 12/31/2022]
Abstract
Recently, vitamin D has aroused considerable interest for several reasons. Many epidemiological studies have shown a widespread deficiency of vitamin D at all ages, and the recent finding that many organs and tissues have vitamin D receptors has fostered the clinical and biological relevance of vitamin D. Elderly people are at high risk for vitamin D deficiency if their life style entails few outdoor activities, their skin is thick and they exhibit impairment of renal function. In the elderly, vitamin D deficiency is very important because it can affect the function of many organs such as the muscle-skeletal, cardio-vascular systems and kidney, and may be involved in various diseases and pathological conditions including type II diabetes, cancer and cognitive decline. In the present review, the most relevant features of vitamin D are described as well as the clinical consequences of hypovitaminosis D in the elderly. Finally, the role of an adequate oral supplementation in the geriatric population is stressed.
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Affiliation(s)
- Annalisa Timpini
- Geriatric Unit, Spedali Civili-University of Brescia (c/o Fondazione Richiedei Gussago), Brescia, Italy
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88
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Wang XX, Jiang T, Shen Y, Santamaria H, Solis N, Arbeeny C, Levi M. Vitamin D receptor agonist doxercalciferol modulates dietary fat-induced renal disease and renal lipid metabolism. Am J Physiol Renal Physiol 2011; 300:F801-10. [PMID: 21209008 DOI: 10.1152/ajprenal.00338.2010] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Diet-induced obesity (DIO) and insulin resistance in mice are associated with proteinuria, renal mesangial expansion, accumulation of extracellular matrix proteins, and activation of oxidative stress, proinflammatory cytokines, profibrotic growth factors, and the sterol regulatory element binding proteins, SREBP-1 and SREBP-2, that mediate increases in fatty acid and cholesterol synthesis. The purpose of the present study was to determine whether treatment of DIO mice with the vitamin D receptor (VDR) agonist doxercalciferol (1α-hydroxyvitamin D2) prevents renal disease. Our results indicate that treatment of DIO mice with the VDR agonist decreases proteinuria, podocyte injury, mesangial expansion, and extracellular matrix protein accumulation. The VDR agonist also decreases macrophage infiltration, oxidative stress, proinflammatory cytokines, and profibrotic growth factors. Furthermore, the VDR agonist also prevents the activation of the renin-angiotensin-aldosterone system including the angiotensin II type 1 receptor and the mineralocorticoid receptor. An additional novel finding of our study is that activation of VDR results in decreased accumulation of neutral lipids (triglycerides and cholesterol) and expression of adipophilin in the kidney by decreasing SREBP-1 and SREBP-2 expression and target enzymes that mediate fatty acid and cholesterol synthesis and increasing expression of the farnesoid X receptor. This study therefore demonstrates multiple novel effects of VDR activation in the kidney which prevent renal manifestations of DIO in the kidney.
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Affiliation(s)
- Xiaoxin X Wang
- Department of Medicine, University of Colorado, Denver, Colorado, USA
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89
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Abstract
In healthy individuals, vitamin D produced in the skin or derived from nutritional sources is converted to 25-hydroxyvitamin D (25[OH]D) in the liver, and then 1,25-dihydroxyvitamin D (1,25[OH](2)D) by 1 alpha-hydroxylase in the kidney. Chronic kidney disease (CKD) is accompanied by a progressive decline in the ability to produce 1,25(OH)(2)D; thus, replacement of this hormonal form of vitamin D has been the focus of therapeutic interventions to prevent and treat complications such as hypocalcemia, and secondary hyperparathyroidism. New research suggests that conversion of 25(OH)D to 1,25(OH)(2)D outside of the kidney may have important biological roles beyond those traditionally ascribed to vitamin D. 25(OH)D levels have increasingly been linked to important clinical outcomes in CKD. This article reviews vitamin D metabolism, emerging new roles for vitamin D, and data surrounding the potential importance of nutritional sources of vitamin D in the management of patients with CKD.
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Affiliation(s)
- Ishir Bhan
- Division of Nephrology, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA.
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90
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Joergensen C, Gall MA, Schmedes A, Tarnow L, Parving HH, Rossing P. Vitamin D levels and mortality in type 2 diabetes. Diabetes Care 2010; 33:2238-43. [PMID: 20606205 PMCID: PMC2945166 DOI: 10.2337/dc10-0582] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To evaluate vitamin D as a predictor of all-cause and cardiovascular mortality and risk of progression to micro- or macroalbuminuria in type 2 diabetic patients. RESEARCH DESIGN AND METHODS In a longitudinal observational follow-up study, 289 type 2 diabetic patients with normoalbuminuria (n = 172), microalbuminuria (n = 73), and macroalbuminuria (n = 44) at baseline were followed for a median (range) of 15.0 (0.2-23) years. Mean ± SD age was 54 ± 9 years. Plasma 25-hydroxyvitamin D(3) levels were determined by high-performance liquid chromatography/tandem mass spectrometry on baseline samples. Severe vitamin D deficiency was defined as the lower 10th percentile (<13.9 nmol/l). RESULTS Median (range) vitamin D level was 35.7 (5-136.7) nmol/l. Vitamin D levels were not associated with age, sex, estimated glomerular filtration rate, urinary albumin excretion rate (UAER), or A1C at baseline, but low levels were weakly associated with elevated systolic blood pressure (R = 0.13, P = 0.03). During follow-up, 196 (68%) patients died. All-cause mortality was increased in patients with severe vitamin D deficiency (hazard ratio 1.96 [95% CI 1.29-2.98]). The association persisted after adjustment for UAER, A1C, diabetes duration, and conventional cardiovascular risk factors (2.03 [1.31-3.13]). Severe vitamin D deficiency was associated with increased cardiovascular mortality (1.95 [1.11-3.44]), and the association persisted after adjustment (1.90 [1.15-3.10]). Severe vitamin D deficiency at baseline did not predict progression to micro- or macroalbuminuria. CONCLUSIONS In type 2 diabetic patients, severe vitamin D deficiency predicts increased risk of all-cause and cardiovascular mortality, independent of UAER and conventional cardiovascular risk factors. Whether vitamin D substitution improves prognosis remains to be investigated.
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91
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Baeke F, Gysemans C, Korf H, Mathieu C. Vitamin D insufficiency: implications for the immune system. Pediatr Nephrol 2010; 25:1597-606. [PMID: 20180136 DOI: 10.1007/s00467-010-1452-y] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2009] [Revised: 12/15/2009] [Accepted: 01/04/2010] [Indexed: 02/07/2023]
Abstract
Chronic kidney disease (CKD) is characterized by a loss of kidney function and dysregulation of vitamin D metabolism. Well known are the defects in final activation of vitamin D to 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)], resulting in renal osteodystrophy. However, in recent years, 1,25(OH)(2)D(3) has been identified as having effects far beyond calcium and bone metabolism. In this review, specific attention is given to the effects of 1,25(OH)(2)D(3) on the immune system and the implications of vitamin D deficiency, a feature of many patients with CKD, on immune function.
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Affiliation(s)
- Femke Baeke
- Laboratory of Experimental Medicine and Endocrinology, Katholieke Universiteit Leuven, Herestraat 49-ON1-bus 902, 3000 Leuven, Belgium
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92
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Helvig CF, Cuerrier D, Hosfield CM, Ireland B, Kharebov AZ, Kim JW, Ramjit NJ, Ryder K, Tabash SP, Herzenberg AM, Epps TM, Petkovich M. Dysregulation of renal vitamin D metabolism in the uremic rat. Kidney Int 2010; 78:463-72. [DOI: 10.1038/ki.2010.168] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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93
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Posner GH, Helvig C, Cuerrier D, Collop D, Kharebov A, Ryder K, Epps T, Petkovich M. Vitamin D analogues targeting CYP24 in chronic kidney disease. J Steroid Biochem Mol Biol 2010; 121:13-9. [PMID: 20347976 DOI: 10.1016/j.jsbmb.2010.03.065] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Revised: 03/16/2010] [Accepted: 03/22/2010] [Indexed: 11/24/2022]
Abstract
The cytochrome P450 enzyme 24-hydroxylase (CYP24) plays a critical role in regulating levels of vitamin D hormone. Aberrant expression of CYP24 has been implicated in vitamin D insufficiency and resistance to vitamin D therapy. We have demonstrated amplified CYP24 expression in uremic rats, suggesting that CYP24 has an etiological role in vitamin D insufficiency commonly associated with chronic kidney disease (CKD). We have designed two new analogues of 1alpha,25-dihydroxyvitamin D3 (1alpha,25(OH)2D3), namely CTA091 and CTA018/MT2832, which are potent inhibitors of CYP24. In vitro studies with CTA091 show that it enhances the potency of 1alpha,25(OH)2D3. In vivo studies demonstrate that CTA091 decreases serum intact parathyroid hormone (iPTH) levels and increases circulating 1alpha,25(OH)2D3. CTA091 increases both Cmax and AUC of co-administered 1alpha,25(OH)2D3. These studies indicate that CYP24 inhibition can increase cellular responsiveness to vitamin D hormone and potentiate vitamin D therapy. CTA018/MT2832 differs from CTA091 in that it also has the ability to activate vitamin D receptor-mediated transcription. CTA018/MT2832 effectively suppresses elevated iPTH secretion at doses which do not affect serum calcium or phosphorus levels in a rodent model of CKD. Studies with both new analogues underscore the potential utility of CYP24 inhibition in the treatment of secondary hyperparathyroidism in CKD.
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Affiliation(s)
- Gary H Posner
- Department of Chemistry, The Johns Hopkins University, Baltimore, MD 21218, USA
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94
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Alteraciones del Metabolismo óseo y mineral en enfermedad renal crónica pre-diálisis. REVISTA MÉDICA CLÍNICA LAS CONDES 2010. [DOI: 10.1016/s0716-8640(10)70568-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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95
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Rojas-Rivera J, De La Piedra C, Ramos A, Ortiz A, Egido J. The expanding spectrum of biological actions of vitamin D. Nephrol Dial Transplant 2010; 25:2850-65. [PMID: 20525641 DOI: 10.1093/ndt/gfq313] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Jorge Rojas-Rivera
- IIS-Fundación Jimenez Diaz, Division of Nephrology and Hypertension, Laboratory of Experimental Nephrology and Vascular Pathology, Madrid, Spain.
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96
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Possible renoprotection by vitamin D in chronic renal disease: beyond mineral metabolism. Nat Rev Nephrol 2009; 5:691-700. [DOI: 10.1038/nrneph.2009.185] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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97
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Martin RJL, McKnight AJ, Patterson CC, Sadlier DM, Maxwell AP. A rare haplotype of the vitamin D receptor gene is protective against diabetic nephropathy. Nephrol Dial Transplant 2009; 25:497-503. [DOI: 10.1093/ndt/gfp515] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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98
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Thadhani R. Is calcitriol life-protective for patients with chronic kidney disease? J Am Soc Nephrol 2009; 20:2285-90. [PMID: 19679671 DOI: 10.1681/asn.2009050494] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Affiliation(s)
- Ravi Thadhani
- Renal Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.
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99
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Bibliography. Current world literature. Curr Opin Endocrinol Diabetes Obes 2009; 16:328-37. [PMID: 19564733 DOI: 10.1097/med.0b013e32832eb365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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100
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Agarwal R. Vitamin D, proteinuria, diabetic nephropathy, and progression of CKD. Clin J Am Soc Nephrol 2009; 4:1523-8. [PMID: 19478099 DOI: 10.2215/cjn.02010309] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Although the endocrine effects of vitamin D are widely recognized, somewhat less appreciated is that vitamin D may serve paracrine functions through local activation by 1-alpha-hydroxylase and thus maintain immunity, vascular function, cardiomyocyte health, and abrogate inflammation and insulin resistance. In the kidney, vitamin D may be important for maintaining podocyte health, preventing epithelial-to-mesenchymal transformation, and suppressing renin gene expression and inflammation. Replacement with pharmacologic dosages of vitamin D receptor agonists (VDRA) in animal models of kidney disease consistently show reduction in albuminuria, abrogation of glomerulosclerosis, glomerulomegaly, and glomerular inflammation, effects that may be independent of BP and parathyroid hormone, but the effects of VDRA in preventing tubulointerstitial fibrosis and preventing the progression of kidney failure in these animal models are less clear. Emerging evidence in patients with chronic kidney disease (CKD) show that vitamin D can reduce proteinuria or albuminuria even in the presence of angiotensin-converting enzyme inhibition. In addition to reducing proteinuria, VDRA may reduce insulin resistance, BP, and inflammation and preserve podocyte loss providing biologic plausibility to the notion that the use of VDRA may be associated with salubrious outcomes in patients with diabetic nephropathy. Patients with CKD have a very high prevalence of deficiency of 25-hydroxyvitamin D. Whether pharmacologic dosages of vitamin D instead of VDRA in patients with CKD can overcome the paracrine and endocrine functions of this vitamin remains unknown. To demonstrate the putative benefits of native vitamin D and VDRA among patients with CKD, randomized, controlled trials are needed.
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Affiliation(s)
- Rajiv Agarwal
- Indiana University School of Medicine and Richard L Roudebush VA Medical Center, Indianapolis, IN 46202, USA.
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