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1.
J Diabetes Sci Technol ; 16(5): 1309-1337, 2022 09.
Article in English | MEDLINE | ID: mdl-35904143

ABSTRACT

The annual Virtual Hospital Diabetes Meeting was hosted by Diabetes Technology Society on April 1 and April 2, 2022. This meeting brought together experts in diabetes technology to discuss various new developments in the field of managing diabetes in hospitalized patients. Meeting topics included (1) digital health and the hospital, (2) blood glucose targets, (3) software for inpatient diabetes, (4) surgery, (5) transitions, (6) coronavirus disease and diabetes in the hospital, (7) drugs for diabetes, (8) continuous glucose monitoring, (9) quality improvement, (10) diabetes care and educatinon, and (11) uniting people, process, and technology to achieve optimal glycemic management. This meeting covered new technology that will enable better care of people with diabetes if they are hospitalized.


Subject(s)
Coronavirus Infections , Diabetes Mellitus, Type 1 , Diabetes Mellitus , Blood Glucose , Blood Glucose Self-Monitoring , Coronavirus Infections/epidemiology , Diabetes Mellitus/therapy , Hospitals , Humans
2.
Life (Basel) ; 11(7)2021 Jun 29.
Article in English | MEDLINE | ID: mdl-34209500

ABSTRACT

To investigate differences in hemodynamic, hormonal and heart rate variability parameters in women following complication-free pregnancies (healthy), preeclampsia and gestational diabetes mellitus (GDM) after giving childbirth. Data of 60 women (healthy: n = 29, age 32.7 ± 4.5 years, BMI 24.2 ± 4.3 kg/m2; preeclampsia: n = 16, age 35.3 ± 4.4 years, 28.5 ± 6.4 kg/m2; GDM, n = 15, age 32.3 ± 6.0 years, BMI 26.4 ± 6.2 kg/m2) were included. Two visits were conducted 16 and 48 weeks after giving childbirth. Hair samples were taken for analysis of cortisol and testosterone. ECG and blood pressure were recorded at each visit. Data were analyzed via RM-ANOVA and post-hoc testing (p ≤ 0.05). Heart rate increased from visit 1 to visit 2, whereas SDNN decreased (both p = 0.03). RMSSD showed an increased trend for groups (p = 0.06). Testosterone in the GDM group was significantly higher compared to the other groups (p = 0.002). Cortisol levels were significantly higher following post-hoc testing GDM was different compared to healthy individuals (p = 0.02). Hemodynamic changes from week 16 to week 48 did not differ between groups (p > 0.05). No differences between individuals with preeclampsia and healthy individuals were found for all hemodynamic parameters (p > 0.05). The study showed higher levels of chronic stress indicators in GDM measured via heart rate variability and cortisol compared to women with a history of preeclampsia and healthy women.

3.
PLoS One ; 15(9): e0239091, 2020.
Article in English | MEDLINE | ID: mdl-32915897

ABSTRACT

INTRODUCTION: To investigate the glycaemic response, macronutrient intake and insulin management in people with type 1 diabetes (T1D) compared to healthy individuals around a running competition. MATERIAL AND METHODS: This was a single-centre, prospective, controlled observational study performed in individuals with T1D and healthy people. 24 people (12 T1D) were included in this study (age: T1D 41±12 vs. healthy 38±6 years, females: 3 vs. 6, BMI: 25.53.0 vs. 22.9±2.8 kg/m2). Both groups received an intermittently scanned continuous glucose monitoring (isCGM; FreeStyle Libre 1, Abbott, USA) system to assess glycaemia 24 hours before, during and 24 hours after a running competition. During this period, participants recorded their food intake and insulin administration. Data were analysed via ANOVA and mixed model analyses with post-hoc testing (p≤0.05). RESULTS: For overall glycaemic ranges in comparison of groups, significant differences were found for time in range (T1D 63±21% vs. healthy 89±13%, p = 0.001), time above range (TAR) 1 (T1D 21±15% vs. healthy 0±0%, p<0.001) and TAR 2 (T1D 8 [0-16%] vs. healthy 0±0%, p<0.001). When glycaemic variability was assessed, people with T1D had a higher glycaemic variability compared to healthy individuals (p<0.0001). Basal insulin dose was significantly reduced when compared against the regular pre-study basal insulin dose (pre-study 22±6 vs. pre-competition day 11±9 (-50±41%), p = 0.02; competition day 15±5 (-32± 1%)). CONCLUSION: People with T1D have impaired glucose responses around a running competition compared to healthy individuals. However, basal insulin dose reductions were sufficient to prevent further dysglycaemia. CLINICAL TRIAL ID: drks.de; DRKS00019886.


Subject(s)
Blood Glucose/physiology , Diabetes Mellitus, Type 1/drug therapy , Eating/physiology , Insulin/administration & dosage , Running/physiology , Adolescent , Adult , Aged , Blood Glucose/analysis , Blood Glucose/drug effects , Blood Glucose Self-Monitoring/statistics & numerical data , Case-Control Studies , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 1/physiopathology , Dose-Response Relationship, Drug , Female , Germany , Humans , Male , Middle Aged , Prospective Studies , Young Adult
4.
J Endocr Soc ; 3(1): 135-145, 2019 01 01.
Article in English | MEDLINE | ID: mdl-30591957

ABSTRACT

Context: In subjects with normal fasting glucose (NFG) and normal glucose tolerance (NGT), glucose concentrations >155 mg/dL 1 hour after 75 g of oral glucose predict increased risk of progression to diabetes. Recently, it has been suggested that the mechanism underlying this abnormality is increased gut absorption of glucose. Objective: We sought to determine the rate of systemic appearance of meal-derived glucose in subjects classified by their 1-hour glucose after a 75-g oral glucose challenge. Design: This was a cross-sectional study. Participating subjects underwent a 75-g oral glucose challenge and a labeled mixed meal test. Setting: An inpatient clinical research unit at an academic medical center. Participants: Thirty-six subjects with NFG/NGT participated in this study. Interventions: Subjects underwent an oral glucose tolerance test. Subsequently, they underwent a labeled mixed meal to measure fasting and postprandial glucose metabolism. Main Outcome Measures: We examined ß-cell function and the rate of meal appearance (Meal Ra) in NFG/NGT subjects. Subsequently, we examined the relationship of peak postchallenge glucose with Meal Ra and indices of ß-cell function. Results: Peak glucose concentrations correlated inversely with ß-cell function. No relationship of Meal Ra with peak postchallenge glucose concentrations was observed. Conclusion: In subjects with NFG/NGT, elevated 1-hour peak postchallenge glucose concentrations reflect impaired ß-cell function rather than increased systemic meal appearance.

5.
Nutrients ; 9(6)2017 Jun 17.
Article in English | MEDLINE | ID: mdl-28629132

ABSTRACT

Increasing evidence suggests a possible interaction between vitamin D and insulin-like growth factor-1 (IGF-1). We aimed to investigate effects of vitamin D supplementation on IGF-1 (primary outcome) and calcitriol (1,25(OH)2D) concentrations (secondary outcome). This is a post-hoc analysis of the Styrian Vitamin D Hypertension Trial-a single-center, double-blind, randomized, placebo-controlled trial (RCT) conducted from 2011 to 2014 at the Medical University of Graz, Austria. Two-hundred subjects with arterial hypertension and 25(OH)D concentrations <30 ng/mL were randomized to either receive 2800 IU of vitamin D daily or placebo for eight weeks. A total of 175 participants (mean ± standard deviation age, 60 ± 11 years; 49% women) with available IGF-1 concentrations were included in the present analysis. At baseline, IGF-1 concentrations were significantly correlated with 1,25(OH)2D (r = 0.21; p = 0.005) but not with 25(OH)D (r = -0.008; p = 0.91). In the RCT, vitamin D had no significant effect on IGF-1 (mean treatment effect 3.1; 95% confidence interval -5.6 to 11.9 ng/mL; p = 0.48), but it increased 1,25(OH)2D concentrations (mean treatment effect 9.2; 95% confidence interval 4.4 to 13.9 pg/mL; p ≤ 0.001). In this RCT, in hypertensive patients with low 25(OH)D concentrations, there was no significant effect of vitamin D supplementation on IGF-1 concentrations. However, we observed a cross-sectional correlation between 1,25(OH)2D and IGF-1 and an increase of 1,25(OH)2D after vitamin D supplementation.


Subject(s)
Calcitriol/blood , Insulin-Like Growth Factor I/metabolism , Vitamin D/administration & dosage , Vitamin D/pharmacology , Aged , Calcitriol/metabolism , Double-Blind Method , Female , Gene Expression Regulation/drug effects , Humans , Male , Middle Aged
7.
Nutrients ; 9(5)2017 Apr 27.
Article in English | MEDLINE | ID: mdl-28448457

ABSTRACT

Bone turnover markers (BTMs) are used to evaluate bone health together with bone mineral density and fracture assessment. Vitamin D supplementation is widely used to prevent and treat musculoskeletal diseases but existing data on vitamin D effects on markers of bone resorption and formation are inconsistent. We therefore examined the effects of vitamin D supplementation on bone-specific alkaline phosphatase (bALP), osteocalcin (OC), C-terminal telopeptide (CTX), and procollagen type 1 N-terminal propeptide (P1NP). This is a post-hoc analysis of the Styrian Vitamin D Hypertension Trial, a single-center, double-blind, randomized, placebo-controlled trial (RCT) performed at the Medical University of Graz, Austria (2011-2014). Two hundred individuals with arterial hypertension and 25-hydroxyvitamin D (25[OH]D) levels <75 nmol/L were randomized to 2800 IU of vitamin D daily or placebo for eight weeks. One hundred ninety-seven participants (60.2 ± 11.1 years; 47% women) were included in this analysis. Vitamin D had no significant effect on bALP (mean treatment effect (MTE) 0.013, 95% CI -0.029 to 0.056 µg/L; p = 0.533), CTX (MTE 0.024, 95% CI -0.163 to 0.210 ng/mL, p = 0.802), OC (MTE 0.020, 95% CI -0.062 to 0.103 ng/mL, p = 0.626), or P1NP (MTE -0.021, 95% CI -0.099 to 0.057 ng/mL, p = 0.597). Analyzing patients with 25(OH)D levels <50 nmol/L separately (n = 74) left results largely unchanged. In hypertensive patients with low 25(OH)D levels, we observed no significant effect of vitamin D supplementation for eight weeks on BTMs.


Subject(s)
Bone Remodeling/drug effects , Vitamin D/administration & dosage , Vitamin D/pharmacology , Aged , Alkaline Phosphatase/genetics , Alkaline Phosphatase/metabolism , Biomarkers/blood , Double-Blind Method , Female , Gene Expression Regulation/drug effects , Humans , Male , Middle Aged , Osteocalcin/genetics , Osteocalcin/metabolism , Peptide Fragments/genetics , Peptide Fragments/metabolism , Procollagen/genetics , Procollagen/metabolism , Vitamin D/analogs & derivatives , Vitamin D/blood
8.
Diabetes Obes Metab ; 19(7): 1051-1055, 2017 07.
Article in English | MEDLINE | ID: mdl-28205324

ABSTRACT

Continuous and flash glucose monitoring (GM) systems have been established in diabetes care. We compared the sensor performance of 3 commercially available GM systems. A total of 12 patients with type 1 diabetes were included in a single-centre, open-label study in which the sensor performance of the Abbott FreeStyle libre (Abbott), Dexcom G4 Platinum (Dexcom) and Medtronic MiniMed 640G (Medtronic) systems over 12 hours was compared during mimicked real-life conditions (meals, exercise, hypo- and hyperglycaemia). Sensor performance was determined by fulfilment of ISO 15197:2013 criteria, calculating mean absolute relative difference (MARD), and was also illustrated using Parkes error grid and Bland-Altman plots. Sensor performance during changes in metabolic variables (lactate, betahydroxybutyrate, glucagon, non-esterified-fatty-acids) was determined by Spearman's rank correlation coefficient testing. The systems fulfilled ISO 15197:2013 criteria by 73.2% (Abbott), 56.1% (Dexcom) and 52.0% (Medtronic). The MARDs ± standard deviation in the entire glycaemic range were 13.2% ± 10.9% (Abbott), 16.8% ± 12.3% (Dexcom) and 21.4% ± 17.6% (Medtronic), respectively. All sensors performed less accurately during hypoglycaemia and best during hyperglycaemia. We did not observe an influence of metabolic variables on sensor performance.


Subject(s)
Activities of Daily Living , Diabetes Mellitus, Type 1/metabolism , Glucose/metabolism , Hyperglycemia/diagnosis , Hypoglycemia/diagnosis , Monitoring, Ambulatory/instrumentation , Subcutaneous Tissue/metabolism , Adult , Austria , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 1/drug therapy , Exercise , Glycated Hemoglobin/analysis , Humans , Hyperglycemia/metabolism , Hypoglycemia/chemically induced , Hypoglycemia/metabolism , Hypoglycemic Agents/administration & dosage , Hypoglycemic Agents/adverse effects , Hypoglycemic Agents/therapeutic use , Injections, Subcutaneous , Insulin/administration & dosage , Insulin/adverse effects , Insulin/therapeutic use , Insulin Infusion Systems/adverse effects , Materials Testing , Meals , Middle Aged , Monitoring, Ambulatory/standards , Young Adult
9.
Medicine (Baltimore) ; 95(14): e3272, 2016 Apr.
Article in English | MEDLINE | ID: mdl-27057885

ABSTRACT

Nesidioblastosis is a rare cause of endogenous hyperinsulinemic hypoglycemia in adults. Diagnosis is often challenging and therapeutic options are scarce.In 2009, a 46-year-old female patient presented with recurrent severe hypoglycemia and immediate recovery after glucose ingestion. Although 72-h-fasting test was positive, various imaging technologies (sonography, computed tomography, somatostatin receptor scintigraphy, dopamine receptor positron emission tomography [DOPA-PET]) were negative. Endoscopic ultrasound revealed a lesion in the pancreatic corpus, whereas selective arterial calcium stimulation test, portal venous sampling and GLP-1-receptor scintigraphy were indicative of a lesion in the pancreatic tail, which was surgically removed. The histopathologic examination revealed beta cell hyperplasia and microadenomas expressing glucagon. After surgery, the patient was free of symptoms for 6 months, after which hypoglycemic episodes recurred. After unsuccessful treatment with corticosteroids and somatostatin analogs, treatment with pasireotide, a novel somatostatin analog with high affinity to somatostatin receptor 5 and a possible side effect of hyperglycemia, was initiated (0.6 mg BID). To date, our patient has been free of severe hypoglycemic episodes ever since. Yearly repeated imaging procedures have shown no abnormities over the last 3 years.We report for the first time that pasireotide was successfully used in the treatment of adult nesidioblastosis.


Subject(s)
Nesidioblastosis/drug therapy , Somatostatin/analogs & derivatives , Female , Humans , Middle Aged , Remission Induction , Somatostatin/therapeutic use , Time Factors
10.
J Clin Hypertens (Greenwich) ; 18(6): 543-50, 2016 06.
Article in English | MEDLINE | ID: mdl-26456544

ABSTRACT

High parathyroid hormone (PTH) has been linked with high blood pressure (BP), but the relationship with 24-hour ambulatory blood pressure monitoring is largely unknown. The authors therefore analyzed cross-sectional data of 292 hypertensive patients participating in the Styrian Hypertension Study (mean age, 61±11 years; 53% women). Median plasma PTH (interquartile range) determined after an overnight fast was 49 pg/mL (39-61), mean daytime BP was 131/80±12/9 mm Hg, and mean nocturnal BP was 115/67±14/9 mm Hg. In multivariate regression analyses adjusted for BP and PTH-modifying parameters, PTH was significantly related to nocturnal systolic and diastolic BP (adjusted ß-coefficient 0.140 [P=.03] and 0.175 [P<.01], respectively). PTH was not correlated with daytime BP readings. These data suggest a direct interrelationship between PTH and nocturnal BP regulation. Whether lowering high PTH concentrations reduces the burden of high nocturnal BP remains to be shown in future studies.


Subject(s)
Circadian Rhythm/physiology , Hypertension/blood , Hypertension/physiopathology , Parathyroid Hormone/blood , Aged , Blood Pressure/physiology , Blood Pressure Monitoring, Ambulatory , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Regression Analysis , Risk Factors
11.
Eur J Nutr ; 55(4): 1479-89, 2016 Jun.
Article in English | MEDLINE | ID: mdl-26130323

ABSTRACT

PURPOSE: Vitamin D is well known for its effects on bone mineralisation but has also been attributed immunomodulatory properties. It positively influences human health, but in vivo data describing vitamin D effects on the human gut microbiome are missing. We aimed to investigate the effects of oral vitamin D3 supplementation on the human mucosa-associated and stool microbiome as well as CD8(+) T cells in healthy volunteers. METHODS: This was an interventional, open-label, pilot study. Sixteen healthy volunteers (7 females, 9 males) were endoscopically examined to access a total of 7 sites. We sampled stomach, small bowel, colon, and stools before and after 8 weeks of vitamin D3 supplementation. Bacterial composition was assessed by pyrosequencing the 16S rRNA gene (V1-2), and CD8(+) T cell counts were determined by flow cytometry. RESULTS: Vitamin D3 supplementation changed the gut microbiome in the upper GI tract (gastric corpus, antrum, and duodenum). We found a decreased relative abundance of Gammaproteobacteria including Pseudomonas spp. and Escherichia/Shigella spp. and increased bacterial richness. No major changes occurred in the terminal ileum, appendiceal orifice, ascending colon, and sigmoid colon or in stools, but the CD8(+) T cell fraction was significantly increased in the terminal ileum. CONCLUSION: Vitamin D3 modulates the gut microbiome of the upper GI tract which might explain its positive influence on gastrointestinal diseases, such as inflammatory bowel disease or bacterial infections. The local effects of vitamin D demonstrate pronounced regional differences in the response of the GI microbiome to external factors, which should be considered in future studies investigating the human microbiome.


Subject(s)
Cholecalciferol/pharmacology , Gastrointestinal Microbiome/drug effects , Gastrointestinal Tract/microbiology , Mucous Membrane/microbiology , Adolescent , Adult , CD8-Positive T-Lymphocytes/cytology , Feces/microbiology , Female , Gammaproteobacteria/drug effects , Gammaproteobacteria/isolation & purification , Helicobacter pylori/drug effects , Humans , Male , Pilot Projects , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Young Adult
12.
Clin Immunol ; 161(2): 217-24, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26277548

ABSTRACT

It is unknown if cholecalciferol is able to modify defects in regulatory T cells (Tregs) in type 1 diabetes (T1D). In this randomized, double-blind, placebo controlled trial 30 young patients with new-onset T1D were assigned to cholecalciferol (70IU/kgbodyweight/day) or placebo for 12months. Tregs were determined by FACS-analysis and functional tests were assessed with ex vivo suppression co-cultures at months 0, 3, 6 and 12. Suppressive capacity of Tregs increased (p<0.001) with cholecalciferol from baseline (-1.59±25.6%) to 3 (30.5±39.4%), 6 (44.6±23.8%) and 12months (37.2±25.0%) and change of suppression capacity from baseline to 12months was significantly higher (p<0.05) with cholecalciferol (22.2±47.2%) than placebo (-16.6±21.1%). Serum calcium and parathormone stayed within normal range. This is the first study, which showed that cholecalciferol improved suppressor function of Tregs in patients with T1D and vitamin D could serve as one possible agent in the development of immunomodulatory combination therapies for T1D.


Subject(s)
Cholecalciferol/therapeutic use , Diabetes Mellitus, Type 1/drug therapy , Dietary Supplements , T-Lymphocytes, Regulatory/drug effects , Adolescent , C-Peptide/blood , Child , Cholecalciferol/administration & dosage , Cholecalciferol/blood , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 1/immunology , Double-Blind Method , Fasting/blood , Female , Humans , Male , Pilot Projects , Prospective Studies , T-Lymphocytes, Regulatory/immunology , Time Factors , Treatment Outcome , Vitamins/administration & dosage , Vitamins/therapeutic use
13.
Hypertension ; 65(6): 1195-201, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25801871

ABSTRACT

UNLABELLED: Vitamin D deficiency is a risk factor for arterial hypertension, but randomized controlled trials showed mixed effects of vitamin D supplementation on blood pressure (BP). We aimed to evaluate whether vitamin D supplementation affects 24-hour systolic ambulatory BP monitoring values and cardiovascular risk factors. The Styrian Vitamin D Hypertension Trial is a single-center, double-blind, placebo-controlled study conducted from June 2011 to August 2014 at the endocrine outpatient clinic of the Medical University of Graz, Austria. We enrolled 200 study participants with arterial hypertension and 25-hydroxyvitamin D levels below 30 ng/mL. Study participants were randomized to receive either 2800 IU of vitamin D3 per day as oily drops (n=100) or placebo (n=100) for 8 weeks. Primary outcome measure was 24-hour systolic BP. Secondary outcome measures were 24-hour diastolic BP, N-terminal-pro-B-type natriuretic peptide, QTc interval, renin, aldosterone, 24-hour urinary albumin excretion, homeostasis model assessment-insulin resistance, triglycerides, high-density lipoprotein cholesterol, and pulse wave velocity. A total of 188 participants (mean [SD] age, 60.1 [11.3] years; 47% women; 25-hydroxyvitamin D, 21.2 [5.6] ng/mL) completed the trial. The mean treatment effect (95% confidence interval) for 24-hour systolic BP was -0.4 (-2.8 to 1.9) mm Hg (P=0.712). Triglycerides increased significantly (mean change [95% confidence interval], 17 [1-33] mg/dL; P=0.013), but no further significant effects were observed for secondary outcomes. Vitamin D supplementation in hypertensive patients with low 25-hydroxyvitamin D has no significant effect on BP and several cardiovascular risk factors, but it was associated with a significant increase in triglycerides. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02136771.


Subject(s)
Blood Pressure/drug effects , Cardiovascular Diseases/prevention & control , Dietary Supplements , Hypertension/diagnosis , Hypertension/drug therapy , Vitamin D/administration & dosage , Aged , Austria , Blood Pressure/physiology , Blood Pressure Determination , Double-Blind Method , Female , Follow-Up Studies , Hospitals, University , Humans , Male , Middle Aged , Prospective Studies , Reference Values , Risk Assessment , Severity of Illness Index , Treatment Outcome
14.
Clin Chim Acta ; 436: 268-72, 2014 Sep 25.
Article in English | MEDLINE | ID: mdl-24960364

ABSTRACT

BACKGROUND: Quinolinic acid (QA) is thought to be one of the most important metabolites of the kynurenine pathway with the highest biological activity in apoptotic responses and neurodegenerative diseases. The determination of QA might be of clinical relevance in different patient groups, but currently, only a few laborious methods with high levels of sample volume consumption are available. METHODS: We developed and validated a simple liquid chromatography-tandem mass spectrometric (LC-tandem MS) method for the determination of QA in human serum with low sample volume requirements. RESULTS: The presented method provides high sample throughput with 25 µL aliquots and works in the positive electrospray ionization (ESI) mode. A commercially available QA-d3 was used as internal standard. Specific transitions for QA and QA-d3 were m/z 280→m/z 78 and m/z 283→m/z 81, respectively. The intra- and inter-assay coefficients of variation (CVs) were all below 10%. Applying this method, in 50 healthy humans a mean serum concentration of QA of 350±167 nmol/L (mean±SD) was determined. CONCLUSION: The described method is suitable for large clinical trials, which is of potential clinical importance to elucidate the function of QA and its relationship to different disease patterns and may be applicable for clinical laboratory routine.


Subject(s)
Blood Chemical Analysis/methods , Chromatography, Liquid/methods , Neurotoxins/blood , Quinolinic Acid/blood , Tandem Mass Spectrometry/methods , Adult , Analytic Sample Preparation Methods , Female , Humans , Limit of Detection , Male , Neurotoxins/chemistry , Quality Control , Quinolinic Acid/chemistry
15.
Eur J Nutr ; 53(3): 751-9, 2014 Apr.
Article in English | MEDLINE | ID: mdl-23999998

ABSTRACT

BACKGROUND: Regulatory T cells (Tregs) play a central role in the maintenance of self-tolerance. Animal and in vitro studies suggest that vitamin D is involved in reducing the risk of autoimmunity by modulating Tregs. METHODS: In a double-blind, placebo controlled study in 60 healthy volunteers, we assessed the effect of a 12-week high-dose oral cholecalciferol supplementation (140,000 IU/month) on the number and function of CD4(pos)CD25(high)FoxP3(pos)CD127(dim) Tregs. We also assessed the clinical safety of the supplementation and the effect on the frequency of other immune cells such as monocytes, dendritic cells, natural killer cells, natural killer T cells, B cells and subgroups of T cells. We also tested the in vitro effect of cholecalciferol on Tregs in human cell cultures. RESULTS: By using FACS analysis, ex vivo suppressive co-cultures and apoptosis assays, we were able to show that a cholecalciferol supplementation leads to significantly increased numbers of peripheral Tregs in vivo. Tregs function and the frequency of other immune cells remained unchanged, and no clinically relevant safety concerns were found. The in vitro exposure of human peripheral blood mononuclear cells to cholecalciferol also supported our in vivo findings. CONCLUSIONS: Our results indicate a substantial effect of a supplementation with inactive vitamin D on the immune system of healthy humans in vivo and provide a rationale for future studies to investigate the immunomodulatory effects of vitamin D in autoimmune diseases.


Subject(s)
Adjuvants, Immunologic/administration & dosage , Cholecalciferol/administration & dosage , Dietary Supplements , Leukopoiesis , T-Lymphocytes, Regulatory/immunology , Vitamin D Deficiency/diet therapy , Adjuvants, Immunologic/adverse effects , Adjuvants, Immunologic/metabolism , Adjuvants, Immunologic/therapeutic use , Adult , Apoptosis , Austria , Blood Cell Count , CD4 Antigens/blood , Calcifediol/blood , Cells, Cultured , Cholecalciferol/adverse effects , Cholecalciferol/metabolism , Cholecalciferol/therapeutic use , Coculture Techniques , Dietary Supplements/adverse effects , Double-Blind Method , Female , Forkhead Transcription Factors/blood , Humans , Interleukin-2 Receptor alpha Subunit/blood , Leukocytes, Mononuclear/cytology , Leukocytes, Mononuclear/immunology , Leukocytes, Mononuclear/metabolism , Leukocytes, Mononuclear/pathology , Male , T-Lymphocytes, Regulatory/cytology , T-Lymphocytes, Regulatory/metabolism , T-Lymphocytes, Regulatory/pathology , Vitamin D Deficiency/blood , Vitamin D Deficiency/immunology , Young Adult
16.
PLoS One ; 8(11): e80362, 2013.
Article in English | MEDLINE | ID: mdl-24265815

ABSTRACT

The gastrointestinal immune system is involved in the development of several autoimmune-mediated diseases, including inflammatory bowel disease, multiple sclerosis, and type 1 diabetes mellitus. Alterations in T-cell populations, especially regulatory T cells (Tregs), are often evident in patients suffering from these diseases. To be able to detect changes in T-cell populations in diseased tissue, it is crucial to investigate T-cell populations in healthy individuals, and to characterize their variation among different regions of the gastrointestinal (GI) tract. While limited data exist, quantitative data on biopsies systematically drawn from various regions of the GI tract are lacking, particularly in healthy young humans. In this report, we present the first systematic assessment of how T cells--including Tregs--are distributed in the gastrointestinal mucosa throughout the GI tract of healthy young humans by means of multi-parameter FACS analysis. Gastroduodenoscopy and colonoscopy were performed on 16 healthy volunteers aged between 18 and 32. Biopsies were drawn from seven GI regions, and were used to determine the frequencies of CD8(+)-, CD4(+)- and Tregs in the gastrointestinal mucosa by means of multi-parameter FACS analysis. Our data show that there is significant variation in the baseline T-cell landscape along the healthy human gastrointestinal tract, and that mucosal T-cell analyses from a single region should not be taken as representative of the entire gastrointestinal tract. We show that certain T-cell subsets in the gastrointestinal mucosa vary significantly among regions; most notably, that Tregs are enriched in the appendiceal orifice region and the ascending colon, and that CD8(pos) T cells are enriched in the gastric mucosa.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Gastrointestinal Tract/immunology , T-Lymphocyte Subsets , T-Lymphocytes, Regulatory/immunology , Adult , Age Factors , CD4-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/metabolism , Female , Gastrointestinal Tract/metabolism , Gastrointestinal Tract/microbiology , Humans , Immunity, Mucosal , Immunophenotyping , Intestinal Mucosa/immunology , Intestinal Mucosa/metabolism , Intestinal Mucosa/microbiology , Lymphocyte Count , Lymphoid Tissue/immunology , Lymphoid Tissue/metabolism , Male , Organ Specificity/immunology , Sex Factors , T-Lymphocytes, Regulatory/metabolism , Young Adult
17.
Nutrients ; 5(7): 2502-21, 2013 Jul 05.
Article in English | MEDLINE | ID: mdl-23857223

ABSTRACT

Vitamin D metabolizing enzymes and vitamin D receptors are present in many cell types including various immune cells such as antigen-presenting-cells, T cells, B cells and monocytes. In vitro data show that, in addition to modulating innate immune cells, vitamin D also promotes a more tolerogenic immunological status. In vivo data from animals and from human vitamin D supplementation studies have shown beneficial effects of vitamin D on immune function, in particular in the context of autoimmunity. In this review, currently available data are summarized to give an overview of the effects of vitamin D on the immune system in general and on the regulation of inflammatory responses, as well as regulatory mechanisms connected to autoimmune diseases particularly in type 1 diabetes mellitus.


Subject(s)
Dietary Supplements , Immune System/drug effects , Vitamin D/blood , Adaptive Immunity/drug effects , Adaptive Immunity/physiology , Animals , Autoimmune Diseases/immunology , Diabetes Mellitus, Type 1/immunology , Humans , Immunity, Innate/drug effects , Immunity, Innate/physiology , Nutritional Status , Randomized Controlled Trials as Topic , Receptors, Calcitriol/immunology , Receptors, Calcitriol/metabolism , Seasons , Vitamin D/administration & dosage , Vitamin D/immunology
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