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Mendoza-Garcés L, Velázquez-Alva MC, Cabrer-Rosales MF, Arrieta-Cruz I, Gutiérrez-Juárez R, Irigoyen-Camacho ME. Vitamin D Deficiency is Associated with Handgrip Strength, Nutritional Status and T2DM in Community-Dwelling Older Mexican Women: A Cross-Sectional Study. Nutrients 2021; 13:736. [PMID: 33652581 PMCID: PMC7996586 DOI: 10.3390/nu13030736] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/22/2021] [Accepted: 02/22/2021] [Indexed: 12/15/2022] Open
Abstract
The aim of this study was to evaluate the association between handgrip strength, nutritional status and vitamin D deficiency in Mexican community-dwelling older women. A cross sectional study in women ≥ 60 years-old was performed. Plasma 25-hydroxyvitamin D (25(OH)D) concentrations were measured by a quantitative immunoassay technique. Handgrip strength was assessed using a dynamometer, while nutritional status was assessed through the Full Mini Nutritional Assessment (Full-MNA). A total of 116 women participated in the study, their mean age was 70.3 ± 5.8 years; 49.1% of the study group had plasma 25(OH)D levels lower than 40 nmol/L [16 ng/mL]. Meanwhile, 28.45% of participants had low handgrip strength (<16 kg), and 23.1% were identified at risk of malnutrition/malnourished according with Full-MNA score. Women with 25(OH)D deficiency (<40 nmol/L [16 ng/mL]) were more likely to have low handgrip strength (OR = 2.64, p = 0.025) compared with those with higher 25(OH)D values. Additionally, being malnourished or at risk of malnutrition (OR = 2.53, p = 0.045) or having type 2 diabetes mellitus (T2DM) (OR = 2.92, p = 0.044) was also associated with low 25(OH)D. The prevalence of low plasma 25(OH)D concentrations was high among Mexican active older women. Low handgrip strength, being at risk of malnutrition/malnourished, or diagnosed with T2DM was also associated with Vitamin D deficiency.
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Affiliation(s)
| | - María Consuelo Velázquez-Alva
- Health Care Department, Metropolitan Autonomous University, Unit Xochimilco, Mexico City 04960, Mexico; (M.C.V.-A.); (M.F.C.-R.)
| | - María Fernanda Cabrer-Rosales
- Health Care Department, Metropolitan Autonomous University, Unit Xochimilco, Mexico City 04960, Mexico; (M.C.V.-A.); (M.F.C.-R.)
| | - Isabel Arrieta-Cruz
- National Institute of Geriatrics, Ministry of Health, Mexico City 10200, Mexico;
| | - Roger Gutiérrez-Juárez
- Department of Biomedical Sciences, School of Medicine, Faculty of Higher Studies Zaragoza, National Autonomous University of Mexico, Mexico City 09230, Mexico;
| | - María Esther Irigoyen-Camacho
- Health Care Department, Metropolitan Autonomous University, Unit Xochimilco, Mexico City 04960, Mexico; (M.C.V.-A.); (M.F.C.-R.)
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Pittas AG, Jorde R, Kawahara T, Dawson-Hughes B. Vitamin D Supplementation for Prevention of Type 2 Diabetes Mellitus: To D or Not to D? J Clin Endocrinol Metab 2020; 105:dgaa594. [PMID: 32844212 PMCID: PMC7571449 DOI: 10.1210/clinem/dgaa594] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 08/24/2020] [Indexed: 12/16/2022]
Abstract
CONTEXT Over the last decade, vitamin D has emerged as a risk determinant for type 2 diabetes and vitamin D supplementation has been hypothesized as a potential intervention to lower diabetes risk. Recently, several trials have reported on the effect of vitamin D supplementation on diabetes prevention in people with prediabetes. EVIDENCE ACQUISITION A comprehensive literature review was performed using PubMed, Embase, and ClinicalTrials.gov to identify: (1) recent meta-analyses of longitudinal observational studies that report on the association between blood 25-hydroxyvitamin D (25[OH]D) level and incident diabetes, and (2) clinical trials of adults with prediabetes that have reported on the effect of vitamin D supplementation on incident diabetes. EVIDENCE SYNTHESIS Longitudinal observational studies report highly consistent associations between higher blood 25(OH)D levels and a lower risk of incident diabetes in diverse populations, including populations with prediabetes. Trials in persons with prediabetes show risk reduction in incident diabetes with vitamin D supplementation. In the 3 large trials that were specifically designed and conducted for the prevention of diabetes, vitamin D supplementation, when compared with placebo, reduced the risk of developing diabetes by 10% to 13% in persons with prediabetes not selected for vitamin D deficiency. CONCLUSIONS Results from recent trials are congruent with a large body of evidence from observational studies indicating that vitamin D has a role in modulating diabetes risk. Participant-level meta-analysis of the 3 largest trials should provide a more refined estimate of risk reduction and identify patient populations that are likely to benefit the most from vitamin D supplementation.
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Affiliation(s)
- Anastassios G Pittas
- Division of Endocrinology, Diabetes and Metabolism, Tufts Medical Center, Boston, Massachusetts
| | - Rolf Jorde
- Institute of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway
| | - Tetsuya Kawahara
- Division of Internal Medicine, Kokura Medical Association Health Testing Center, Kitakyushu, Japan
| | - Bess Dawson-Hughes
- Division of Endocrinology, Diabetes and Metabolism, Tufts Medical Center, Boston, Massachusetts
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A network of transcriptional repressors modulates auxin responses. Nature 2020; 589:116-119. [PMID: 33208947 DOI: 10.1038/s41586-020-2940-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 09/04/2020] [Indexed: 11/08/2022]
Abstract
The regulation of signalling capacity, combined with the spatiotemporal distribution of developmental signals themselves, is pivotal in setting developmental responses in both plants and animals1. The hormone auxin is a key signal for plant growth and development that acts through the AUXIN RESPONSE FACTOR (ARF) transcription factors2-4. A subset of these, the conserved class A ARFs5, are transcriptional activators of auxin-responsive target genes that are essential for regulating auxin signalling throughout the plant lifecycle2,3. Although class A ARFs have tissue-specific expression patterns, how their expression is regulated is unknown. Here we show, by investigating chromatin modifications and accessibility, that loci encoding these proteins are constitutively open for transcription. Through yeast one-hybrid screening, we identify the transcriptional regulators of the genes encoding class A ARFs from Arabidopsis thaliana and demonstrate that each gene is controlled by specific sets of transcriptional regulators. Transient transformation assays and expression analyses in mutants reveal that, in planta, the majority of these regulators repress the transcription of genes encoding class A ARFs. These observations support a scenario in which the default configuration of open chromatin enables a network of transcriptional repressors to regulate expression levels of class A ARF proteins and modulate auxin signalling output throughout development.
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Hosseinzadeh M, Razmpoosh E, Elham shareghfarid, Hosseinzadeh E, Hadinedoushan H, Salami MA, Khosravi M, Amini M, Mozaffari-Khosravi H. The effect of a single mega dose injection of vitamin D on serum adiponectin concentration at first gestational diabetes mellitus: A randomized controlled clinical trial. CLINICAL NUTRITION EXPERIMENTAL 2020. [DOI: 10.1016/j.yclnex.2020.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Liu Q, Zheng X, Liu Z, Qiu L. Vitamin D status is associated with 1,5-anhydro-d-glucitol status in patients with type 2 diabetes mellitus. Appl Physiol Nutr Metab 2019; 44:857-860. [PMID: 30633541 DOI: 10.1139/apnm-2018-0719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Serum 1,5-anhydro-d-glucitol (1,5-AG) concentrations are short-term hyperglycemia indicators and were used to estimate the effects of serum vitamin D concentrations on glycemic control in patients with type 2 diabetes mellitus (T2DM). Serum concentrations of 1,5-AG, 25-hydroxyvitamin D2 (25-OH-D2), and 25-hydroxyvitamin D3 (25-OH-D3) from 11 026 patients with T2DM, hospitalized in the Department of Endocrinology, Shanghai Central Hospital of Xuhui District, from January 2012 to June 2015, were retrospectively analyzed. Correlation analyses revealed correlations between 1,5-AG and 25-OH-D3 (r = 0.05, P < 0.001), age (r = 0.05, P < 0.001), and 25-OH-D2 + 25-OH-D3 (25-OH-D2/D3) (r = 0.05, P < 0.001). Linear regression analyses revealed associations between 1,5-AG and 25-OH-D2/D3 (adjusted R2 = 0.003) as well as 25-OH-D3 (adjusted R2 = 0.002). In males with 1,5-AG levels ≤11.55 mg/L, serum concentrations of 25-OH-D2 (P < 0.001) and 25-OH-D3 (P = 0.001) were significantly lower than those in diabetic males with 1,5-AG levels >11.55 mg/L. Serum concentrations of 25-OH-D2/D3 in patients with T2DM were associated with 1,5-AG retention, suggesting involvement in glycemic control.
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Affiliation(s)
- Qiaorui Liu
- Department of Endocrinology, Shanghai Xuhui Central Hospital, No. 966 Huaihai Road, Shanghai 200031, China
| | - Xulei Zheng
- Department of Endocrinology, Shanghai Xuhui Central Hospital, No. 966 Huaihai Road, Shanghai 200031, China
| | - Zhiwen Liu
- Department of Endocrinology, Shanghai Xuhui Central Hospital, No. 966 Huaihai Road, Shanghai 200031, China.,Department of Endocrinology, Shanghai Xuhui Central Hospital, No. 966 Huaihai Road, Shanghai 200031, China
| | - Ling Qiu
- Department of Endocrinology, Shanghai Xuhui Central Hospital, No. 966 Huaihai Road, Shanghai 200031, China.,Department of Endocrinology, Shanghai Xuhui Central Hospital, No. 966 Huaihai Road, Shanghai 200031, China
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Jorde R, Sollid ST, Svartberg J, Schirmer H, Joakimsen RM, Njølstad I, Fuskevåg OM, Figenschau Y, Hutchinson MYS. Vitamin D 20,000 IU per Week for Five Years Does Not Prevent Progression From Prediabetes to Diabetes. J Clin Endocrinol Metab 2016; 101:1647-55. [PMID: 26829443 DOI: 10.1210/jc.2015-4013] [Citation(s) in RCA: 126] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
CONTEXT Vitamin D deficiency is associated with insulin resistance and risk of future diabetes. OBJECTIVE The objective of the study was to test whether supplementation with vitamin D to subjects with prediabetes will prevent progression to type 2 diabetes mellitus (T2DM). DESIGN This was a randomized controlled trial performed in 2008 through 2015. SETTING The study was conducted at the clinical research unit at a teaching hospital. PATIENTS Five hundred eleven subjects (mean age 62 y, 314 males) with prediabetes diagnosed with an oral glucose tolerance test as part of the Tromsø Study 2007–2008 were included. A total of 256 were randomized to vitamin D and 255 to placebo. Twenty-nine subjects in the vitamin D and 24 in the placebo group withdrew because of adverse events. INTERVENTIONS Interventions included vitamin D (cholecalciferol) 20 000 IU/wk vs placebo for 5 years. Annual oral glucose tolerance tests were performed. MAIN OUTCOME MEASURE Progression to T2DM was the main outcome measure. Secondary outcomes were change in glucose levels, insulin resistance, serum lipids, and blood pressure. RESULTS The mean baseline serum 25-hydroxyvitamin D level was 60 nmol/L (24 ng/mL). One hundred three in the vitamin D and 112 in the placebo group developed T2DM (hazard risk 0.90; 95% confidence interval 0.69–1.18, Cox regression, P = .45, intention to treat analysis). No consistent significant effects on the other outcomes were seen. Subgroup analyses in subjects with low baseline 25-hydroxyvitamin D yielded similar results. No serious side effects related to the intervention were recorded. CONCLUSIONS In subjects without vitamin D deficiency, vitamin D supplementation is unlikely to prevent progression from prediabetes to diabetes. Very large studies with inclusion of vitamin D-deficient subjects will probably be needed to show such a putative effect. This study tested if supplementation with vitamin D to subjects with prediabetes will prevent progression to type 2 diabetes (T2DM).
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Affiliation(s)
- Rolf Jorde
- Tromsø Endocrine Research Group (R.J., S.T.S., J.S., R.M.J., Y.F.), Department of Clinical Medicine, Department of Clinical Medicine (H.S.), Epidemiology of Chronic Diseases Research Group (I.N.), Department of Community Medicine, Department of Medical Biology (Y.F.), UiT The Arctic University of Norway, 9037 Tromsø, Norway; Division of Internal Medicine (R.J., S.T.S., J.S., R.M.J.), Division of Diagnostic Services (O.M.F., Y.F.), University Hospital of North Norway, 9038 Tromsø, Norway; and Division of Head and Motion (M.Y.S.H.), Department of Rheumatology, Nordland Hospital, 8092 Bodø, Norway
| | - Stina T Sollid
- Tromsø Endocrine Research Group (R.J., S.T.S., J.S., R.M.J., Y.F.), Department of Clinical Medicine, Department of Clinical Medicine (H.S.), Epidemiology of Chronic Diseases Research Group (I.N.), Department of Community Medicine, Department of Medical Biology (Y.F.), UiT The Arctic University of Norway, 9037 Tromsø, Norway; Division of Internal Medicine (R.J., S.T.S., J.S., R.M.J.), Division of Diagnostic Services (O.M.F., Y.F.), University Hospital of North Norway, 9038 Tromsø, Norway; and Division of Head and Motion (M.Y.S.H.), Department of Rheumatology, Nordland Hospital, 8092 Bodø, Norway
| | - Johan Svartberg
- Tromsø Endocrine Research Group (R.J., S.T.S., J.S., R.M.J., Y.F.), Department of Clinical Medicine, Department of Clinical Medicine (H.S.), Epidemiology of Chronic Diseases Research Group (I.N.), Department of Community Medicine, Department of Medical Biology (Y.F.), UiT The Arctic University of Norway, 9037 Tromsø, Norway; Division of Internal Medicine (R.J., S.T.S., J.S., R.M.J.), Division of Diagnostic Services (O.M.F., Y.F.), University Hospital of North Norway, 9038 Tromsø, Norway; and Division of Head and Motion (M.Y.S.H.), Department of Rheumatology, Nordland Hospital, 8092 Bodø, Norway
| | - Henrik Schirmer
- Tromsø Endocrine Research Group (R.J., S.T.S., J.S., R.M.J., Y.F.), Department of Clinical Medicine, Department of Clinical Medicine (H.S.), Epidemiology of Chronic Diseases Research Group (I.N.), Department of Community Medicine, Department of Medical Biology (Y.F.), UiT The Arctic University of Norway, 9037 Tromsø, Norway; Division of Internal Medicine (R.J., S.T.S., J.S., R.M.J.), Division of Diagnostic Services (O.M.F., Y.F.), University Hospital of North Norway, 9038 Tromsø, Norway; and Division of Head and Motion (M.Y.S.H.), Department of Rheumatology, Nordland Hospital, 8092 Bodø, Norway
| | - Ragnar M Joakimsen
- Tromsø Endocrine Research Group (R.J., S.T.S., J.S., R.M.J., Y.F.), Department of Clinical Medicine, Department of Clinical Medicine (H.S.), Epidemiology of Chronic Diseases Research Group (I.N.), Department of Community Medicine, Department of Medical Biology (Y.F.), UiT The Arctic University of Norway, 9037 Tromsø, Norway; Division of Internal Medicine (R.J., S.T.S., J.S., R.M.J.), Division of Diagnostic Services (O.M.F., Y.F.), University Hospital of North Norway, 9038 Tromsø, Norway; and Division of Head and Motion (M.Y.S.H.), Department of Rheumatology, Nordland Hospital, 8092 Bodø, Norway
| | - Inger Njølstad
- Tromsø Endocrine Research Group (R.J., S.T.S., J.S., R.M.J., Y.F.), Department of Clinical Medicine, Department of Clinical Medicine (H.S.), Epidemiology of Chronic Diseases Research Group (I.N.), Department of Community Medicine, Department of Medical Biology (Y.F.), UiT The Arctic University of Norway, 9037 Tromsø, Norway; Division of Internal Medicine (R.J., S.T.S., J.S., R.M.J.), Division of Diagnostic Services (O.M.F., Y.F.), University Hospital of North Norway, 9038 Tromsø, Norway; and Division of Head and Motion (M.Y.S.H.), Department of Rheumatology, Nordland Hospital, 8092 Bodø, Norway
| | - Ole M Fuskevåg
- Tromsø Endocrine Research Group (R.J., S.T.S., J.S., R.M.J., Y.F.), Department of Clinical Medicine, Department of Clinical Medicine (H.S.), Epidemiology of Chronic Diseases Research Group (I.N.), Department of Community Medicine, Department of Medical Biology (Y.F.), UiT The Arctic University of Norway, 9037 Tromsø, Norway; Division of Internal Medicine (R.J., S.T.S., J.S., R.M.J.), Division of Diagnostic Services (O.M.F., Y.F.), University Hospital of North Norway, 9038 Tromsø, Norway; and Division of Head and Motion (M.Y.S.H.), Department of Rheumatology, Nordland Hospital, 8092 Bodø, Norway
| | - Yngve Figenschau
- Tromsø Endocrine Research Group (R.J., S.T.S., J.S., R.M.J., Y.F.), Department of Clinical Medicine, Department of Clinical Medicine (H.S.), Epidemiology of Chronic Diseases Research Group (I.N.), Department of Community Medicine, Department of Medical Biology (Y.F.), UiT The Arctic University of Norway, 9037 Tromsø, Norway; Division of Internal Medicine (R.J., S.T.S., J.S., R.M.J.), Division of Diagnostic Services (O.M.F., Y.F.), University Hospital of North Norway, 9038 Tromsø, Norway; and Division of Head and Motion (M.Y.S.H.), Department of Rheumatology, Nordland Hospital, 8092 Bodø, Norway
| | - Moira Y S Hutchinson
- Tromsø Endocrine Research Group (R.J., S.T.S., J.S., R.M.J., Y.F.), Department of Clinical Medicine, Department of Clinical Medicine (H.S.), Epidemiology of Chronic Diseases Research Group (I.N.), Department of Community Medicine, Department of Medical Biology (Y.F.), UiT The Arctic University of Norway, 9037 Tromsø, Norway; Division of Internal Medicine (R.J., S.T.S., J.S., R.M.J.), Division of Diagnostic Services (O.M.F., Y.F.), University Hospital of North Norway, 9038 Tromsø, Norway; and Division of Head and Motion (M.Y.S.H.), Department of Rheumatology, Nordland Hospital, 8092 Bodø, Norway
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Osati S, Homayounfar R, Hajifaraji M. Metabolic effects of vitamin D supplementation in vitamin D deficient patients (a double-blind clinical trial). Diabetes Metab Syndr 2016; 10:S7-S10. [PMID: 27094871 DOI: 10.1016/j.dsx.2016.01.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 01/09/2016] [Indexed: 01/08/2023]
Abstract
BACKGROUND Vitamin D has recently been given a lot of attention for its role in controlling insulin secretion. Many studies have spoken of its role in weight management, blood sugar control and many other metabolic variables. PATIENT AND METHODS In a randomized double-blind clinical trial, 210 people with vitamin D deficiency were randomly allocated into two groups receiving vitamin D (50,000 units per week) or placebo for 8 weeks. RESULTS Vitamin D levels were significantly increased in the group receiving vitamin D supplementation (13.7±5.2 unit increase versus 0.8±2.8). The increased levels of vitamin D lead to significant changes in fasting insulin levels (6.8±8.1 unit reduction versus 2.3±3.7), a 2-h insulin (31.1±34.9 unit reduction versus 4.5±24.6) and Homeostasis Model Assessment (HOMA) indices. CONCLUSION Correction of vitamin D deficiency leads to increased insulin sensitivity that was significantly able to maintain glucose in the normal range with lower levels of insulin.
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Affiliation(s)
- Saeed Osati
- National Nutrition and Food Technology Research Institute, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Reza Homayounfar
- Noncommunicable diseases research center, Fasa University of Medical Sciences, Fasa, Iran
| | - Majid Hajifaraji
- National Nutrition and Food Technology Research Institute, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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Shahgheibi S, Farhadifar F, Pouya B. The effect of vitamin D supplementation on gestational diabetes in high-risk women: Results from a randomized placebo-controlled trial. JOURNAL OF RESEARCH IN MEDICAL SCIENCES 2016; 21:2. [PMID: 27904548 PMCID: PMC5122001 DOI: 10.4103/1735-1995.175148] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Revised: 10/17/2015] [Accepted: 12/08/2015] [Indexed: 12/03/2022]
Abstract
Background: Vitamin D deficiency is common in pregnancy, leading to increase in the frequency of preeclampsia, cesarean delivery, neonatal bacterial vaginosis, and gestational diabetes. The current study was designed and implemented to investigate the effect of vitamin D during the first and second trimesters of pregnancy in reducing the risk of gestational diabetes mellitus (GDM) in women who are at high risk [history of GDM, birth macrosomia, family history, and high body mass index (BMI)]. Materials and Methods: In a randomized, double-blind, and placebo-controlled trial, 90 pregnant women who had at least one risk factor for GDM were randomized into intervention (46 participants) and control (44 participants) groups. Participants in the intervention group took 5000 units of vitamin D daily and the control group took placebo until the 26th week of pregnancy. Then the glucose challenge test (GCT) and the glucose tolerance test (GTT) were performed to evaluate GDM. Results: Mean ± standard deviation (SD) age was 31.28 ± 6.38 years and 29 ± 6.24 years for the intervention group and the placebo group, respectively, (P > 0.05). In addition, there were no significant differences between two groups in terms of vitamin D levels and GCT (P > 0.05), and the difference was not significant. The incidence of diabetes in the intervention groups was statistically lower than in control group (11.4% vs 34.8; P < 0.01). The results showed that abnormal GCT in the placebo group was statistically higher than in intervention group (35.9% vs 10.9 P < 0.005). Conclusion: The results of the current study showed that the prescription of vitamin D supplementation in the first and second trimesters of pregnancy was effective in reducing GDM and controlling GTT and GTC.
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Affiliation(s)
- Shole Shahgheibi
- Department of Obstetrics and Gynecology, Kurdistan University of Medical Sciences, Sanandaj, Iran
| | - Fariba Farhadifar
- Department of Obstetrics and Gynecology, Kurdistan University of Medical Sciences, Sanandaj, Iran
| | - Bahar Pouya
- Department of Obstetrics and Gynecology, Kurdistan University of Medical Sciences, Sanandaj, Iran
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9
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Vitamin D Status in Women with Gestational Diabetes Mellitus during Pregnancy and Postpartum. BIOMED RESEARCH INTERNATIONAL 2015; 2015:260624. [PMID: 26000285 PMCID: PMC4427001 DOI: 10.1155/2015/260624] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 01/30/2015] [Accepted: 02/11/2015] [Indexed: 02/08/2023]
Abstract
Of many vitamin D extraskeletal functions, its modulatory role in insulin secretion and action is especially relevant for gestational diabetes mellitus (GDM). The aims of the present study were to determine midgestational and early postpartum vitamin D status in pregnant women with and without GDM and to describe the relationship between midgestational and postpartum vitamin D status and parallel changes of glucose tolerance. A total of 76 pregnant women (47 GDM and 29 healthy controls) were included in the study. Plasma levels of 25(OH)D were measured using an enzyme immunoassay. Vitamin D was not significantly decreased in GDM compared to controls during pregnancy; however, both groups of pregnant women exhibited high prevalence of vitamin D deficiency. Prevalence of postpartum 25(OH)D deficiency in post-GDM women remained significantly higher and their postpartum 25(OH)D levels were significantly lower compared to non-GDM counterparts. Finally, based on the oGTT repeated early postpartum persistent glucose abnormality was ascertained in 15% of post-GDM women; however, neither midgestational nor postpartum 25(OH)D levels significantly differed between subjects with GDM history and persistent postpartum glucose intolerance and those with normal glucose tolerance after delivery.
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Flood-Nichols SK, Tinnemore D, Huang RR, Napolitano PG, Ippolito DL. Vitamin D deficiency in early pregnancy. PLoS One 2015; 10:e0123763. [PMID: 25898021 PMCID: PMC4405493 DOI: 10.1371/journal.pone.0123763] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 02/23/2015] [Indexed: 11/18/2022] Open
Abstract
Objective Vitamin D deficiency is a common problem in reproductive-aged women in the United States. The effect of vitamin D deficiency in pregnancy is unknown, but has been associated with adverse pregnancy outcomes. The objective of this study was to analyze the relationship between vitamin D deficiency in the first trimester and subsequent clinical outcomes. Study Design This is a retrospective cohort study. Plasma was collected in the first trimester from 310 nulliparous women with singleton gestations without significant medical problems. Competitive enzymatic vitamin D assays were performed on banked plasma specimens and pregnancy outcomes were collected after delivery. Logistic regression was performed on patients stratified by plasma vitamin D concentration and the following combined clinical outcomes: preeclampsia, preterm delivery, intrauterine growth restriction, gestational diabetes, and spontaneous abortion. Results Vitamin D concentrations were obtained from 235 patients (mean age 24.3 years, range 18-40 years). Seventy percent of our study population was vitamin D insufficient with a serum concentration less than 30 ng/mL (mean serum concentration 27.6 ng/mL, range 13-71.6 ng/mL). Logistic regression was performed adjusting for age, race, body mass index, tobacco use, and time of year. Adverse pregnancy outcomes included preeclampsia, growth restriction, preterm delivery, gestational diabetes, and spontaneous abortion. There was no association between vitamin D deficiency and composite adverse pregnancy outcomes with an adjusted odds ratio of 1.01 (p value 0.738, 95% confidence intervals 0.961-1.057). Conclusion Vitamin D deficiency did not associate with adverse pregnancy outcomes in this study population. However, the high percentage of affected individuals highlights the prevalence of vitamin D deficiency in young, reproductive-aged women.
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Affiliation(s)
- Shannon K. Flood-Nichols
- Division of Maternal-Fetal Medicine, Madigan Army Medical Center, Joint Base Lewis-McChord, Tacoma, Washington, United States of America
- * E-mail:
| | - Deborah Tinnemore
- Department of Clinical Investigation, Madigan Army Medical Center, Joint Base Lewis-McChord, Tacoma, Washington, United States of America
| | - Raywin R. Huang
- Department of Clinical Investigation, Madigan Army Medical Center, Joint Base Lewis-McChord, Tacoma, Washington, United States of America
| | - Peter G. Napolitano
- Division of Maternal-Fetal Medicine, Madigan Army Medical Center, Joint Base Lewis-McChord, Tacoma, Washington, United States of America
| | - Danielle L. Ippolito
- Department of Clinical Investigation, Madigan Army Medical Center, Joint Base Lewis-McChord, Tacoma, Washington, United States of America
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Peterson CA, Tosh AK, Belenchia AM. Vitamin D insufficiency and insulin resistance in obese adolescents. Ther Adv Endocrinol Metab 2014; 5:166-89. [PMID: 25489472 PMCID: PMC4257980 DOI: 10.1177/2042018814547205] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Obese adolescents represent a particularly vulnerable group for vitamin D deficiency which appears to have negative consequences on insulin resistance and glucose homeostasis. Poor vitamin D status is also associated with future risk of type 2 diabetes and metabolic syndrome in the obese. The biological mechanisms by which vitamin D influences glycemic control in obesity are not well understood, but are thought to involve enhancement of peripheral/hepatic uptake of glucose, attenuation of inflammation and/or regulation of insulin synthesis/secretion by pancreatic β cells. Related to the latter, recent data suggest that the active form of vitamin, 1,25-dihydroxyvitamin D, does not impact insulin release in healthy pancreatic islets; instead they require an environmental stressor such as inflammation or vitamin D deficiency to see an effect. To date, a number of observational studies exploring the relationship between the vitamin D status of obese adolescents and markers of glucose homeostasis have been published. Most, although not all, show significant associations between circulating 25-hydroxyvitamn D concentrations and insulin sensitivity/resistance indices. In interpreting the collective findings of these reports, significant considerations surface including the effects of pubertal status, vitamin D status, influence of parathyroid hormone status and the presence of nonalcoholic fatty liver disease. The few published clinical trials using vitamin D supplementation to improve insulin resistance and impaired glucose tolerance in obese adolescents have yielded beneficial effects. However, there is a need for more randomized controlled trials. Future investigations should involve larger sample sizes of obese adolescents with documented vitamin D deficiency, and careful selection of the dose, dosing regimen and achievement of target 25-hydroxyvitamn D serum concentrations. These trials should also include clamp-derived measures of in vivo sensitivity and β-cell function to more fully characterize the effects of vitamin D replenishment on insulin resistance.
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Affiliation(s)
- Catherine A Peterson
- University of Missouri, Department of Nutrition and Exercise Physiology, 204 Gwynn Hall, Columbia, MO 65211, USA
| | - Aneesh K Tosh
- Department of Child Health, University of Missouri School of Medicine, University of Missouri, Columbia, MO, USA
| | - Anthony M Belenchia
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, USA
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Cheng Q, Boucher BJ, Leung PS. Modulation of hypovitaminosis D-induced islet dysfunction and insulin resistance through direct suppression of the pancreatic islet renin-angiotensin system in mice. Diabetologia 2013; 56:553-62. [PMID: 23250033 DOI: 10.1007/s00125-012-2801-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 11/26/2012] [Indexed: 12/12/2022]
Abstract
AIMS/HYPOTHESIS Vitamin D is necessary for normal insulin action and suppresses renin production. Increased renin-angiotensin system (RAS) activity causes islet damage, including reduced insulin secretion. We therefore sought to determine whether hypovitaminosis D-induced upregulation of islet RAS in vivo impairs islet cell function and increases insulin resistance, and whether pharmacological suppression of the RAS during continuing vitamin D deficiency might correct this. METHODS C57BL/6 mice were rendered vitamin D-deficient by diet, and glucose and insulin tolerance was assessed. The expression and translation of islet functional, and islet RAS, genes were measured and the effects of pharmacological renin suppression examined. RESULTS Mice with diet-induced hypovitaminosis D developed impaired glucose tolerance, increased RAS component expression and impaired islet function gene transcription. Treatment with pharmacological renin inhibition (aliskiren), without vitamin D status correction, reduced islet RAS over-reactivity, islet dysfunction and insulin resistance, and improved glucose tolerance. CONCLUSIONS/INTERPRETATION Upregulation of islet RAS genes can contribute to hypovitaminosis D-induced impairment of islet function and increase insulin resistance independently of vitamin D status. Thus, our findings support the use of RAS inhibitors in impaired glucose homeostasis or early diabetes. They also suggest that combining RAS inhibition with correction of hypovitaminosis D might be useful in treating impaired glycaemic control and also in type 2 diabetes prevention. However, the use of aliskiren in established diabetes is contraindicated due to the increased risk of side effects such as hyperkalaemia, so other more suitable RAS blockers need to be identified.
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Affiliation(s)
- Q Cheng
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Room 609A, Lo Kwee-Seong Integrated Biomedical Sciences Building, Shatin, Hong Kong Special Administrative Region, People's Republic of China
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13
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14
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Vitamin D, type 2 diabetes and other metabolic outcomes: a systematic review and meta-analysis of prospective studies. Proc Nutr Soc 2012; 72:89-97. [PMID: 23107484 DOI: 10.1017/s0029665112002765] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Vitamin D status may influence the risk of developing metabolic diseases such as Type 2 diabetes (T2D), metabolic syndrome (MetS) and insulin resistance (IR). Several studies have assessed vitamin D in relationship with metabolic outcomes; however, results remain inconsistent. A systematic review and meta-analysis using multiple databases (MEDLINE, Web of Science and EMBASE), was performed up to 10 August 2012. Prospective studies reporting association of circulating or dietary vitamin D with incident T2D, MetS and IR outcomes were included. Relative risks (RR) were pooled using random effects and subgroup analysis by pertinent study-level characteristics was performed. A total of seventeen articles based on eighteen unique prospective studies, and comprising 210 107 participants with 15 899 metabolic events, collected during a median follow up of 10 years (range 3-22 years), were included. RR for individuals in top v. bottom thirds of baseline vitamin D were 0·81 (95% CI 0·71, 0·92); 0·86 (95% CI 0·80, 0·92); and 0·84 (95% CI 0·64, 1·12) for T2D, MetS and IR outcomes, respectively. Moderate heterogeneity was found between fourteen studies (I 2 = 67%, P < 0·001) reporting on T2D. Findings were generally consistent across various study-level characteristics. In conclusion, vitamin D status at baseline in apparently healthy adults is inversely associated with future risks of T2D and MetS. Interventions aimed at maintaining adequate levels of vitamin D in addition to preventing deficiency may be a useful preventive measure for metabolic diseases. However, reliable evidence from carefully designed intervention studies, particularly those based on healthy populations, is needed to confirm observational findings.
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Friedman DJ, Bhatt N, Hayman NS, Nichols BJ, Herman M, Nikolaev N, Danziger J. Impact of activated vitamin D on insulin resistance in nondiabetic chronic kidney disease patients. Clin Endocrinol (Oxf) 2012; 77:56-61. [PMID: 21913955 PMCID: PMC3638771 DOI: 10.1111/j.1365-2265.2011.04229.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
UNLABELLED Although vitamin D deficiency has been associated with increased insulin resistance, a causal link has not been established. Interpreting the relationship has been confounded by a close correlation between vitamin D deficiency and obesity. The current clinical approach of assessing endogenous 25-hydroxyvitamin D (25(OH)D) concentrations in patients with chronic kidney disease (CKD), and independently administering activated vitamin D (AD), allows a unique opportunity to clarify cause and effect in the relationship of vitamin D, obesity and insulin resistance. METHODS We assessed how 25(OH)D and body mass index (BMI) related to fasting insulin concentrations in 120 nondiabetic patients with CKD. In addition, we described how treatment with AD modified these relationships. RESULTS In the full cohort, fasting insulin concentrations varied inversely with both 25(OH)D (r = -0·22, P = 0·02) and BMI (r = -0·36, P < 0·0001). The administration of AD altered these relationships. In individuals treated with AD, there was no association between 25(OH)D and fasting insulin, and the mean fasting insulin concentrations were significantly lower than in those not receiving AD (40·5 ± 22·0 vs 54·1 ± 30·9 pm, P = 0·01). In a multivariate analysis, both AD treatment and BMI were independent predictors of fasting insulin. Furthermore, obese patients treated with AD had insulin concentrations similar to nonobese patients (46·1 ± 24·9 vs 40·2 ± 21·5 pm), whereas untreated obese patients had markedly higher fasting insulin concentrations (74·4 ± 33·4 pm, P = 0·003). CONCLUSION 25(OH)D deficiency is associated with insulin resistance in CKD. Replacement with pharmacologic doses of AD is associated with lower fasting insulin concentrations, especially in obese patients.
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Affiliation(s)
- David J. Friedman
- Division of Nephrology Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Nisha Bhatt
- Division of Nephrology Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Najwah S. Hayman
- Division of Nephrology Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Brendan J. Nichols
- Division of Nephrology Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Mark Herman
- Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Nikolay Nikolaev
- Department of Mathematics and Statistics, Boston University, Boston, Massachusetts
| | - John Danziger
- Division of Nephrology Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
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Wolden-Kirk H, Overbergh L, Christesen HT, Brusgaard K, Mathieu C. Vitamin D and diabetes: its importance for beta cell and immune function. Mol Cell Endocrinol 2011; 347:106-20. [PMID: 21889571 DOI: 10.1016/j.mce.2011.08.016] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2011] [Revised: 08/08/2011] [Accepted: 08/12/2011] [Indexed: 02/06/2023]
Abstract
Experimental evidence indicates that vitamin D may play a role in the defense against type 1 diabetes (T1D) as well as type 2 diabetes (T2D). Epidemiological data have established a link between vitamin D deficiency and an increased incidence of both T1D and T2D, whereas early and long-term vitamin D supplementation may decrease the risk of these disorders. The protective effects of vitamin D are mediated through the regulation of several components such as the immune system and calcium homeostasis. However, an increasing amount of evidence suggests that vitamin D also affects beta cells directly thereby rendering them more resistant to the types of cellular stress encountered during T1D and T2D. This review evaluates the role of vitamin D signaling in the pathogenesis of T1D and T2D with a special emphasis on the direct effects of vitamin D on pancreatic beta cells.
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Affiliation(s)
- Heidi Wolden-Kirk
- Laboratory of Experimental Medicine and Endocrinology, University Hospital Gasthuisberg, Catholic University of Leuven, B-3000 Leuven, Belgium.
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17
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Nazarian S, St Peter JV, Boston RC, Jones SA, Mariash CN. Vitamin D3 supplementation improves insulin sensitivity in subjects with impaired fasting glucose. Transl Res 2011; 158:276-81. [PMID: 22005267 PMCID: PMC3196850 DOI: 10.1016/j.trsl.2011.05.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 04/18/2011] [Accepted: 05/13/2011] [Indexed: 12/20/2022]
Abstract
Vitamin D has in vitro and in vivo effects on β cells and insulin sensitivity. Vitamin D deficiency (VDD) has been associated with the onset and progression of type 2 diabetes mellitus (DM-2). However, studies involving supplementation of vitamin D in subjects with previously established diabetes have demonstrated inconsistent effects on insulin sensitivity. The aim of this open-label study was to assess the effects of high-dose vitamin D3 supplementation on insulin sensitivity in subjects with VDD and impaired fasting glucose. We studied 8 subjects with VDD and prediabetes with the modified, frequently sampled intravenous glucose tolerance (mFSIGT) test before and after vitamin D supplementation. Vitamin D3 was administered as 10,000 IU daily for 4 weeks. The mFSIGT was analyzed with MinMod Millennium (purchased from Dr. Richard Bergman, Keck School of Medicine of USC, Los Angeles, Calif) to obtain estimates of acute insulin response to glucose (AIRg), insulin sensitivity (SI), and disposition index (DI). We found that AIRg decreased (P = 0.011) and SI increased (P = 0.012) after a intervention with vitamin D. If these findings are repeated in a randomized, double-blind study, the results indicate that orally administered high-dose vitamin D3 supplementation improves insulin sensitivity in subjects with impaired fasting glucose and suggests that high-dose vitamin D3 supplementation might provide an inexpensive public health measure in preventing, or at least delaying, the progression from impaired fasting glucose to diabetes.
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Affiliation(s)
- Shaban Nazarian
- Division of Endocrinology and Diabetes, University of Minnesota, Minneapolis, USA
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18
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Soheilykhah S, Mojibian M, Rashidi M, Rahimi-Saghand S, Jafari F. Maternal Vitamin D Status in Gestational Diabetes Mellitus. Nutr Clin Pract 2010; 25:524-7. [DOI: 10.1177/0884533610379851] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Sedigheh Soheilykhah
- Yazd Diabetes Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Mahdieh Mojibian
- Yazd Diabetes Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Maryam Rashidi
- Yazd Diabetes Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | | | - Fatemeh Jafari
- Yazd Diabetes Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
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19
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Liu E, Meigs JB, Pittas AG, Economos CD, McKeown NM, Booth SL, Jacques PF. Predicted 25-hydroxyvitamin D score and incident type 2 diabetes in the Framingham Offspring Study. Am J Clin Nutr 2010; 91:1627-33. [PMID: 20392893 PMCID: PMC2869511 DOI: 10.3945/ajcn.2009.28441] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Accumulating evidence suggests that vitamin D is involved in the development of type 2 diabetes (T2D). OBJECTIVE Our objective was to examine the relation between vitamin D status and incidence of T2D. DESIGN We used a subsample of 1972 Framingham Offspring Study participants to develop a regression model to predict plasma 25-hydroxyvitamin D [25(OH)D] concentrations from age, sex, body mass index, month of blood sampling, total vitamin D intake, smoking status, and total energy intake. Using this model, we calculated the predicted 25(OH)D score for each nondiabetic participant at the cohort's fifth examination to assess the association between the predicted 25(OH)D score and incidence of T2D by using Cox proportional hazards models. RESULTS A total of 133 T2D cases were identified over a 7-y average follow-up. In comparison with individuals in the lowest tertile of the predicted 25(OH)D score at baseline, those in the highest tertile had a 40% lower incidence of T2D after adjustment for age, sex, waist circumference, parental history of T2D, hypertension, low HDL cholesterol, elevated triglycerides, impaired fasting glucose, and Dietary Guidelines for Americans Adherence Index score (hazard ratio: 0.60; 95% CI: 0.37, 0.97; P for trend = 0.03). CONCLUSIONS Our findings suggest that higher vitamin D status is associated with decreased risk of T2D. Maintaining optimal 25(OH)D status may be a strategy to prevent the development of T2D.
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Affiliation(s)
- Enju Liu
- Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA
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20
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Bodnar LM, Simhan HN. Vitamin D may be a link to black-white disparities in adverse birth outcomes. Obstet Gynecol Surv 2010; 65:273-84. [PMID: 20403218 PMCID: PMC3222336 DOI: 10.1097/ogx.0b013e3181dbc55b] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
UNLABELLED In the United States, significant, intractable disparities exist in rates of major pregnancy outcomes between non-Hispanic black and non-Hispanic white women. A previously unexplored candidate influence on the black-white disparity in adverse birth outcomes is maternal vitamin D status. This review summarizes the evidence relating maternal vitamin D to preeclampsia, spontaneous preterm birth, gestational diabetes, and fetal growth restriction, and addresses gaps in our understanding of the contribution of vitamin D to the intractable black-white disparity in these conditions. The literature reviewed highlights strong biologic plausibility of role for vitamin D in the pathophysiology of these poor pregnancy outcomes. Data also suggest that maternal vitamin D deficiency may increase the risk of preeclampsia and fetal growth restriction. Less research has been done in support of relations with spontaneous preterm birth and gestational diabetes, and fetal and infant survival have rarely been studied. Few trials of vitamin D supplementation have been conducted in pregnant women with adequate power to test effects on birth outcomes. Importantly, black pregnant women have rarely been studied in vitamin D-birth outcomes research. Although vitamin D is a promising candidate influence on black-white disparities in preeclampsia, spontaneous preterm birth, fetal growth restriction, and gestational diabetes, these associations require further study in large samples of black US women. Because vitamin D deficiency is widespread and black-white disparities in pregnancy outcomes and infant survival have been resistant to previous interventions, research to test vitamin D as a causal factor is of major public health significance. TARGET AUDIENCE Obstetricians & Gynecologist, Family Physicians. LEARNING OBJECTIVES After completion of this educational activity, the reader will be able to appreciate risk factors for inadequate vitamin D status. Understand the basic aspects of vitamin D metabolism. Become aware of recent literature linking inadequate vitamin D status and adverse pregnancy outcomes such as preeclampsia and preterm birth.
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Affiliation(s)
- Lisa M Bodnar
- Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA 15261, USA.
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de Boer IH, Tinker LF, Connelly S, Curb JD, Howard BV, Kestenbaum B, Larson JC, Manson JE, Margolis KL, Siscovick DS, Weiss NS. Calcium plus vitamin D supplementation and the risk of incident diabetes in the Women's Health Initiative. Diabetes Care 2008; 31:701-7. [PMID: 18235052 PMCID: PMC3046029 DOI: 10.2337/dc07-1829] [Citation(s) in RCA: 264] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Experimental and epidemiologic studies suggest that calcium and vitamin D may reduce the risk of developing diabetes. We examined the effect of calcium plus vitamin D supplementation on the incidence of drug-treated diabetes in postmenopausal women. RESEARCH DESIGN AND METHODS The Women's Health Initiative Calcium/Vitamin D Trial randomly assigned postmenopausal women to receive 1,000 mg elemental calcium plus 400 IU of vitamin D3 daily, or placebo, in a double-blind fashion. Among 33,951 participants without self-reported diabetes at baseline, we ascertained by treatment assignment new diagnoses of diabetes treated with oral hypoglycemic agents or insulin. Effects of the intervention on fasting measurements of glucose, insulin, and insulin resistance were examined among a subset of participants. RESULTS Over a median follow-up time of 7 years, 2,291 women were newly diagnosed with diabetes. The hazard ratio for incident diabetes associated with calcium/vitamin D treatment was 1.01 (95% CI 0.94-1.10) based on intention to treat. This null result was robust in subgroup analyses, efficacy analyses accounting for nonadherence, and analyses examining change in laboratory measurements. CONCLUSIONS Calcium plus vitamin D3 supplementation did not reduce the risk of developing diabetes over 7 years of follow-up in this randomized placebo-controlled trial. Higher doses of vitamin D may be required to affect diabetes risk, and/or associations of calcium and vitamin D intake with improved glucose metabolism observed in nonrandomized studies may be the result of confounding or of other components of foods containing these nutrients.
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Affiliation(s)
- Ian H de Boer
- Division of Nephrology, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA.
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Maghbooli Z, Hossein-Nezhad A, Karimi F, Shafaei AR, Larijani B. Correlation between vitamin D3 deficiency and insulin resistance in pregnancy. Diabetes Metab Res Rev 2008; 24:27-32. [PMID: 17607661 DOI: 10.1002/dmrr.737] [Citation(s) in RCA: 180] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND The serum level of 25-hydroxyvitamin D deficiency has long been suspected as a risk factor for glucose intolerance and perhaps 1,25-dihydroxyvitamin D has a role in the regulation of insulin secretion. This study investigates the relation between 25-hydroxyvitamin D concentrations and insulin resistance in pregnant women. METHODS A cross-sectional study was conducted on 741 pregnant women referred to five educating hospital clinics. Universal screening was performed with a GCT-50 g, and those with plasma glucose levels > pr = 7.2 mmol/L were diagnosed as GDM if they had an impaired GTT-100 g based on Carpenter and Coustan criteria. The levels of insulin and C-peptide were measured during OGTT-100 g test. The homeostasis model assessment index (HOMA) equation was used as the insulin resistance index. The concentrations of 25-hydroxyvitamin D, and PTH were also measured. RESULTS Total prevalence of vitamin D deficiency (<25 nmol/L) was found in 70.6% of pregnant women. Prevalence of severe vitamin D deficiency (<12.5) in GDM patients was higher than in normoglycaemic pregnancies. The regression model revealed a strong correlation between the HOMA index and serum levels of vitamin D. CONCLUSIONS These results show that a positive correlation of 25(OH) vitamin D concentrations with insulin sensitivity and vitamin D deficiency could be a confirmative sign of insulin resistance.
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Affiliation(s)
- Zhila Maghbooli
- Endocrinology & Metabolism Research Center, Tehran University of Medical Sciences, Tehran, Iran.
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Kajikawa M, Ishida H, Fujimoto S, Mukai E, Nishimura M, Fujita J, Tsuura Y, Okamoto Y, Norman AW, Seino Y. An insulinotropic effect of vitamin D analog with increasing intracellular Ca2+ concentration in pancreatic beta-cells through nongenomic signal transduction. Endocrinology 1999; 140:4706-12. [PMID: 10499529 DOI: 10.1210/endo.140.10.7025] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The effect of 1alpha,25-dihydroxylumisterol3 (1alpha,25(OH)2lumisterol3) on insulin release from rat pancreatic beta-cells was measured to investigate the nongenomic action of vitamin D via the putative membrane vitamin D receptor (mVDR). 1Alpha,25(OH)2lumisterol3, a specific agonist of mVDR, dose-dependently augmented 16.7 mM glucose-induced insulin release from rat pancreatic islets and increased the intracellular Ca2+ concentration ([Ca2+]i), though not increasing Ca2+ efficacy in the exocytotic system. These effects were completely abolished by an antagonist of mVDR, 1beta,25-dihydroxyvitamin D3 (1beta,25(OH)2D3), or by a blocker of voltage-dependent Ca2+ channels, nitrendipine. Moreover, both [Ca2+]i elevation, caused by membrane depolarization, and sufficient intracellular glucose metabolism are required for the expression of these effects. 1Alpha,25(OH)2lumisterol3, therefore, has a rapid insulinotropic effect, through nongenomic signal transduction via mVDR, that would be dependent on the augmentation of Ca2+ influx through voltage-dependent Ca2+ channels on the plasma membrane, being also linked to metabolic signals derived from glucose in pancreatic beta-cells. However, further investigations will be needed to discuss physiologically the meaning of insulinotropic effects of vitamin D through mVDR.
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Affiliation(s)
- M Kajikawa
- Department of Metabolism and Clinical Nutrition, Graduate School of Medicine, Kyoto University, Japan.
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Boucher BJ. Inadequate vitamin D status: does it contribute to the disorders comprising syndrome 'X'? Br J Nutr 1998; 79:315-27. [PMID: 9624222 DOI: 10.1079/bjn19980055] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Environmental factors are important in the aetiology of glucose intolerance, type II diabetes and IHD. The lack of vitamin D, which is necessary for adequate insulin secretion, relates demographically to increased risk of myocardial infarction. These disorders are connected, degenerative vascular disease increasing with glucose intolerance and diabetes and, with its risk factors, comprising syndrome 'X'. Evidence is presented suggesting that vitamin D deficiency may be an avoidable risk factor for syndrome 'X', adding another preventative measure to current recommendations which are aimed at reducing the worldwide epidemic of these disorders. Experimentally, vitamin D deficiency progressively reduces insulin secretion; glucose intolerance follows and becomes irreversible. Relationships between vitamin D status, glucose tolerance and 30 min insulin secretion during oral glucose tolerance tests are reported in British Asians; insulin secretion, but not glycaemia, improving with short-term supplementation. Studies showing reduction in blood pressure and in risk of heart attack and diabetes with exercise (usually outdoor), rarely consider the role of vitamin D status. Glycaemia and insulin secretion in elderly European men, however, relate to vitamin D status, independent of season or physical activity. Prolonged supplementation can improve glycaemia. Hypertension improves with vitamin D treatment with or without initial deficiency. Vitamin D status and climate are reviewed as risk factors for myocardial infarction; the risk reducing with altitude despite increasing cold. Glycaemia and fibrinogenaemia improve with insulin secretion increases in summer. Variation in vitamin D requirements could arise from genetic differences in vitamin D processing since bone density can vary with vitamin D-receptor genotype. Vitamin D receptors are present in islet beta cells and we report insulin secretion in healthy Asians differing profoundly with the Apa I genotype, being independent of vitamin D status. Those at risk of vitamin D deficiency include the elderly, those living indoors or having a covered-up style of dress, especially dark-skinned immigrants, and pregnant women, and these are groups recognized as being at increased risk of diabetes.
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Affiliation(s)
- B J Boucher
- Academic Medical Unit, St. Bartholomew's and the Royal London Hospital Medical & Dental School, UK
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25
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Faure-Dussert AG, Delbancut AP, Billaudel BJ. Low extracellular calcium enhances beta cell sensitivity to the stimulatory influence of 1,25-dihydroxyvitamin D3 on insulin release by islets from vitamin D3-deficient rats. Steroids 1997; 62:554-62. [PMID: 9253796 DOI: 10.1016/s0039-128x(97)00041-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The beneficial effect of 1,25-dihydroxyvitamin D3 [1,25 (OH)2 D3] on insulin secretion from beta cells in hypocalcemic vitamin D3-deficient rats is now well established. Moreover, few data concerning the mechanism of 1,25 (OH) 2D3 efficiency as a function of the severity of hypocalcemia. In the present experiment, we submitted islets from vitamin D3-deficient rats to in vitro exposure to a range of decreasing extracellular Ca2+ concentrations ([Ca2+]ex), from 0.5 mM to 0.6 mM, during a 6-h 10-8 M 1,25 (OH) 2D3 induction. Thereafter, we compared the effect of this pretreatment on the islets' insulin response to a given stimulus. Various stimuli were used, and we measured in parallel the variations of 86Rb+ and 45Ca2+ efflux and insulin release into the perifusion medium. In the presence of 1,25 (OH) 2D3, we observed an inverse correlation between the [Ca2+]ex pre-exposure and the amplitude of the insulin response to certain stimuli studied, suggesting that beta cells that were pre-exposed to low [Ca2+]ex became more sensitive to the beneficial effect of 1,25 (OH) 2D3 on insulin release. This effect was observed when beta cells were activated by acetylcholine but only during its second phase of stimulation, and more particularly with the barium plus theophylline stimulus. In contrast, insulin release was not affected by [Ca2+]ex pre-exposure during 1,25 (OH) 2D3 induction in response to acetylcholine during its first phase of stimulation, thus excluding any mechanism mediated via nutrient pathways, membrane depolarization, or inositol triphosphate (IP3)-dependent events. Moreover, the islets that were pre-exposed to a 10-fold [Ca2+]ex exhibited only a 50% lower 45Ca2+ content after 45Ca2+ loading, suggesting a different or relatively more efficient storage capacity in the presence of low extracellular calcium. Studies of 45Ca2+ efflux showed that the mobilization of Ca2+ stores induced by a barium plus theophylline stimulus, in the absence of calcium in the perifusion medium, was more efficient in islets pre-exposed to low [Ca2+]ex, whereas the acetylcholine-IP 3-induced mobilization of Ca2+ from reticular stores was not affected. These results generated the hypothesis that 1,25 (OH)2D3 may prepare the beta cells during their pre-exposure to low [Ca2+]ex to become more efficient as concerns insulin release via a more efficient mobilization of 45Ca2+ stores (mitochondrial?) and by an activation of release potentiating systems via protein kinase C protein kinase A pathways.
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Affiliation(s)
- A G Faure-Dussert
- Laboratoire d'Endocrinologie, Université de Bordeaux, Talence, France
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Bourlon PM, Faure-Dussert A, Billaudel B. Modulatory role of 1,25 dihydroxyvitamin D3 on pancreatic islet insulin release via the cyclic AMP pathway in the rat. Br J Pharmacol 1997; 121:751-8. [PMID: 9208144 PMCID: PMC1564753 DOI: 10.1038/sj.bjp.0701204] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
1. Previous studies have shown that vitamin D3 deficiency impairs the insulin response to glucose via an alteration of signal transduction pathways, such as Ca2+ handling and the phosphoinositide pathway. In the present study the adenylyl cyclase pathway was examined in islets from 3 independent groups: normal rats, 4 weeks-vitamin D3 deficient rats and one week-1,25 dihydroxyvitamin D3 (1,25(OH)2D3) treated rats. 2. We found that the very low rate of insulin release observed in vitamin D3 deficient rats could be restored in vitamin D3 deficient islets only with high concentrations of dioctanoyl-cyclic AMP (DO-cyclic AMP), whereas 1,25(OH)2D3 improved the sensitivity of the islets to this exogenous cyclic AMP analogue. 3. The beneficial effect of 1,25(OH)2D3 observed with or without DO-cyclic AMP was protein kinase A-dependent, since the addition of N-[2-(p-bromocinnamylamino) ethyl]-5-isoquinolinesulphonamide (H-89), a specific inhibitor of cyclic AMP-dependent protein kinases, decreased the insulin release of treated rats back to the level seen in vitamin D3 deficient islets. 4. The low rate of insulin release could not be consistently related to an alteration in cyclic AMP content of the islets. Indeed, low insulin response to a barium+theophylline stimulus observed in vitamin D3 deficient islets was paradoxically associated with a supranormal cyclic AMP content in the islets. 5. This paradoxical increase in cyclic AMP observed in these conditions could not be attributed to a lower total phosphodiesterase (PDE) activity, although the portion of Ca(2+)-calmodulin-independent PDE was predominant in islets from vitamin D3 deficient rats. 6. On the other hand, the higher cyclic AMP content of vitamin D3 deficient islets could be related to an increase in glucagon-induced cyclic AMP synthesis in relation to the hyperglucagonaemia previously observed in vitamin D3 deficient rats. Since higher concentrations of exogenous glucagon and higher endogenous cyclic AMP concentrations were required in vitro to restore insulin release to normal values, the cyclic AMP-dependent pathways that usually potentiate insulin secretion appeared to be less efficient in relation to an alteration in the post cyclic AMP effector system. 7. 1,25(OH)2D3 exerted a stimulating effect on insulin release via protein kinase A activation but reduced the supranormal cyclic AMP synthesis, thus exerting a differential modulatory influence on biochemical disturbances in islets induced by vitamin D3 deficiency.
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Affiliation(s)
- P M Bourlon
- Laboratoire d'Endocrinologie, Université de Bordeaux 1, Talence Cedex, France
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Billaudel BJ, Bourlon PM, Sutter BC, Faure-Dussert AG. Regulatory effect of 1,25-dihydroxyvitamin D3 on insulin release and calcium handling via the phospholipid pathway in islets from vitamin D-deficient rats. J Endocrinol Invest 1995; 18:673-82. [PMID: 8719297 DOI: 10.1007/bf03349788] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The effect of 10(-8) M 1,25-dihydroxyvitamin D3 [1,25 (OH)2D3] on the phosphoinositide pathway, was studied on [3H] inositol and 45Ca2+ efflux and on insulin release of islets from vitamin D-deficient rats, during an acetylcholine (Ach) stimulus in perifusion. The insulin release, which was low in vitamin D-deficient rats, was enhanced by this treatment. The 3H flux, reflecting phosphoinositide breakdown, was also increased. The 45Ca2+ flux was stimulated both during the first 14 min peak (mobilization of IP3-sensitive reticular Ca2+ stores) and during the following sustained small elevation of 45Ca2+ flux, reflecting protein kinase C (PKC) activation and consequently increased phosphorylation of Ca2+ channel proteins. These effects were larger during perifusions performed in the presence of glucose which is known to open Ca2+ channels, suggesting a synergistic influence of glucose and 1,25(OH)2D3. This positive influence of 1,25(OH)2D3 in Ca2+ entry by Ca2+ channels was confirmed by the use of nifedipine-a Ca2+ channel blocker-which suppressed the 45Ca2+ flux and lowered insulin secretion. Moreover, the sustained 45Ca2+ flux also disappeared in islets from vitamin D-deficient rats supplemented by 1,25(OH)2D3 but perifused without extracellular Ca2+ supporting the hypothesis of 1,25(OH)2D3-induced activation of PKC. Thus, 1,25(OH)2D3 may provide supplementary calcium to the B cell by regulating the intracellular signalling processes involving phospholipid metabolism, PKC induction, Ca2+ mobilization and Ca2+ entry by Ca2+ channels.
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Affiliation(s)
- B J Billaudel
- Laboratoire d'Endocrinologie, Université de Bordeaux I, France
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Scragg R, Holdaway I, Singh V, Metcalf P, Baker J, Dryson E. Serum 25-hydroxyvitamin D3 levels decreased in impaired glucose tolerance and diabetes mellitus. Diabetes Res Clin Pract 1995; 27:181-8. [PMID: 7555599 DOI: 10.1016/0168-8227(95)01040-k] [Citation(s) in RCA: 215] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A cross-sectional survey was carried out in a New Zealand Polynesian and Caucasian workforce of 5677 staff aged 40-64 years to determine whether serum concentrations of 25-hydroxyvitamin D3 are altered in people with newly diagnosed diabetes mellitus and impaired glucose tolerance (IGT). Serum 25-hydroxyvitamin D3 concentration was significantly lower in newly detected cases with diabetes and IGT (n = 238) compared with controls individually matched by sex, age (+/- 2 years), ethnicity, and date of interview (mean (S.D.): 69 (31) vs. 76 (34) nmol/l; P = 0.0016). Among controls, serum concentrations were significantly lower in Maori (mean (S.E.) = 65 (5) nmol/l; P = 0.0013) and Pacific Islanders (59 (4) nmol/l; P = 0.0001) compared with Europeans (82 (3) nmol/l), after adjusting for age, sex, and time of year. We conclude that diabetes and IGT are associated with low serum concentrations of 25-hydroxyvitamin D3 and that low concentrations of this hormone in New Zealand Polynesians may partly explain their increased prevalence of diabetes/IGT compared with Europeans.
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Affiliation(s)
- R Scragg
- Department of Community Health, University of Auckland, New Zealand
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Billaudel BJ, Delbancut AP, Sutter BC, Faure AG. Stimulatory effect of 1,25-dihydroxyvitamin D3 on calcium handling and insulin secretion by islets from vitamin D3-deficient rats. Steroids 1993; 58:335-41. [PMID: 8212082 DOI: 10.1016/0039-128x(93)90094-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Among the various vitamin D3 metabolites, 1,25-(OH)2D3 is the specific secosteroid hormone that can enhance, in vitro, the weak insulin response to glucose of islets from vitamin D3-deficient rats. Because this potentiating effect is preceded by an increase in Ca2+ handling, several putative sites of action were studied by measuring 45Ca2+ and 86Rb+ (as K+ tracer) efflux during perifusions in the presence of various stimuli known to affect Ca2+ movements in different ways: high glucose without calcium, high calcium without glucose, high potassium, or barium-theophylline without calcium or glucose. The present results show that 1,25-(OH)2D3 may activate Ca2+ handling by at least two mechanisms: (1) an increase of Ca2+ entry via voltage-dependent Ca2+ channels in the experiments in which extracellular Ca2+ was present and where Ca2+ channels were opened; this 1,25-(OH)2D3 influence on Ca2+ channels was not mediated by a possible indirect influence on K+ channels because 86Rb+ fluxes were never observed to be affected by the steroid; (2) an enhancement of 45Ca2+ mobilization from intracellular stores as suggested by barium-theophylline stimulation and probably also via the Ca2+ stimulus. Both of these 1,25-(OH)2D3 influences tended to provide more calcium to the B cell of vitamin D3-deficient rats. But this prerequisite was not sufficient in itself to potentiate the insulin response; indeed, experiments with barium-theophylline suggested that 1,25-(OH)2D3 may also activate a cAMP-dependent exocytosis process.
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Affiliation(s)
- B J Billaudel
- Laboratoire d'Endocrinologie, UFR de Biologie, Université Bordeaux I, Talence, France
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Billaudel BJ, Faure AG, Sutter BC. Effect of 1,25 dihydroxyvitamin D3 on isolated islets from vitamin D3-deprived rats. THE AMERICAN JOURNAL OF PHYSIOLOGY 1990; 258:E643-8. [PMID: 2185647 DOI: 10.1152/ajpendo.1990.258.4.e643] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Insulin release is impaired by vitamin D3 deficiency but can be restored by in vivo administration of 1,25 dihydroxyvitamin D3 [1,25(OH)2D3]. A direct influence of 1,25(OH)2D3 on the B-cell was studied in vitro with islets from 5-wk vitamin D3-deprived rats. This hormone (10(-12) to 10(-6) mol/l) added to the incubation medium had a stimulatory dose-dependent effect on insulin response to 8.3 mmol/l glucose 6 h later. Moreover, perifusion experiments performed after different times of incubation demonstrated that after 6 h 1,25(OH)2D3 increased in particular the first phase of insulin response to 16.7 mmol/l glucose. The 45Ca fluxes, followed in parallel, were never modified by 1,25(OH)2D3 in the absence of glucose but were enhanced during the glucose stimulus, whereas 86Rb fluxes were never affected by 1,25(OH)2D3. These results demonstrated that 1,25(OH)2D3 acts in vitro on B-cells, but with a 6-h delay to potentiate the glucose-induced insulin release, concomitant with intracellular calcium redistribution.
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Affiliation(s)
- B J Billaudel
- Laboratoire d'Endocrinologie, Universite de Bordeaux I, Talence, France
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Malaisse WJ, Blachier F, Pochet R, Manuel y Keenoy B, Sener A. Calmodulin and calbindin in pancreatic islet cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1990; 269:127-33. [PMID: 2191550 DOI: 10.1007/978-1-4684-5754-4_20] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The process of insulin release evoked by D-glucose and other nutrient secretagogues is triggered by an increase in cytosolic Ca2+ activity. However, some other insulinotropic agents may stimulate insulin release at a close-to-basal concentration of cytosolic ionized calcium. The control of cytosolic Ca2+ concentration depends not solely on the rate of Ca2+ entry into the cell through voltage-sensitive channels and Ca2+ exit via Na(+)-Ca2+ countertransport or active Ca2+ pumping, but also on the subcellular distribution of Ca2+, as dependent, for instance, on both Ca2(+)-ATPase activity and inositol 1,4,5-triphosphate-sensitive release in microsomes and calcium accumulation in mitochondria. Calmodulin and calbindin were both identified in pancreatic islet cells. Activation of adenylate cyclase by calcium-calmodulin may account for the increased production of cyclic AMP in islets stimulated by nutrient secretagogues. Calbindin is present in both normal and tumoral islet cells, and might participate to the alteration of islet function encountered in vitamin D-deprived or repleted rats. However, no target enzyme for calbindin was yet identified in islet cells. Independently of the role of calcium-binding regulatory proteins, the mitochondrial accumulation of calcium may account in part at least, for the preferential stimulation of mitochondrial oxidative events in the process of nutrient-stimulated insulin release.
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Affiliation(s)
- W J Malaisse
- Laboratory of Experimental Medicine, Brussels Free University, Belgium
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Pochet R, Blachier F, Lawson DE, Malaisse WJ. Presence of calbindin-D 28K in endocrine pancreatic tumoral cells of the RINm5F line. INTERNATIONAL JOURNAL OF PANCREATOLOGY : OFFICIAL JOURNAL OF THE INTERNATIONAL ASSOCIATION OF PANCREATOLOGY 1989; 5:295-304. [PMID: 2550562 DOI: 10.1007/bf02924474] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Calbindin-D 28K expression in insulin-producing tumoral cells of the RINm5F line was assessed by Western-blot and high pressure liquid chromatography. Western blot analysis demonstrated the presence in RINm5F cell homogenates of a protein recognized by a specific polyclonal antibody against chick calbindin. Proteins with apparent molecular weights (mol wt) of 44, 47, 56, and 85 kD were also recognized by the antiserum in RINm5F cell extract, but not in normal rat islet extract. HPLC heat-resistant protein extract from RINm5F cell homogenates revealed three calbindin positive peaks: a major peak with a retention time (20.5 min) identical to that found in a rat cerebellar extract and two minor peaks with shorter retention times. The calbindin content of RINm5F cells was apparently unaffected after 9 d culture in a medium supplemented with 10% calf serum pretreated with dextran-charcoal to remove 1,25-dihydroxyvitamin D3.
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Affiliation(s)
- R Pochet
- Laboratory of Histology, Faculté de Médecine, Université Libre de Bruxelles, Belgium
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Billaudel B, Labriji-Mestaghanmi H, Sutter BC, Malaisse WJ. Vitamin D and pancreatic islet function. II. Dynamics of insulin release and cationic fluxes. J Endocrinol Invest 1988; 11:585-93. [PMID: 3072374 DOI: 10.1007/bf03350186] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Pancreatic islets were prepared from control and vitamin D-deprived rats 2 or 5 weeks after weaning and, in the latter case, after 3 or 6 days treatment with exogenous vitamin D3 (60 nmol per day). The islets were prelabelled with both 86Rb and 45Ca and placed in a perfusion chamber. Vitamin D deprivation or administration failed to affect 86Rb outflow whether prior or after stimulation of the islets by a rise in either extracellular D-glucose or Ca2+ concentration. However, vitamin D deprivation decreased and vitamin D administration enhanced the basal 45Ca fractional outflow rate, as well as the magnitude of changes in both 45Ca and insulin release evoked by the rise in either D-glucose or extracellular Ca2+. It is proposed that the alteration in 45Ca fluxes and insulin release attributable to changes in the supply of vitamin D are, to a large extent, independent of the changes in nutrient catabolism conceivably associated with vitamin D deprivation and administration.
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Affiliation(s)
- B Billaudel
- Laboratoire de Physiologie Animale (Endocrinologie), Université de Bordeaux, Talence, France
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