Vitamin D supplementation in inflammatory bowel disease: a narrative review. / Suplementación con vitamina D en enfermedad inflamatoria intestinal: una revisión narrativa.

Inflammatory bowel disease is a chronic disorder characterized by exacerbation and remission periods, and its worldwide incidence has increased in recent decades. Vitamin D is involved in immune regulation and improves barrier functions and intestinal microbiota. Studies have observed that high vitamin D levels decrease relapses and improve the clinical course of inflammatory bowel disease. The objective of this review was to analyze the evidence on vitamin D supplementation in adult patients with inflammatory bowel disease. Among inactive patients, the studies administrating less than 2000 international units per day of vitamin D did not find any beneficial effects. However, those supplementing 2000 international units of vitamin D per day increased serum levels and reduced disease activity. In patients with active disease, doses between 5000 to 10 000 international units per day reduced symptomatology. This review showed that vitamin D supplementation above 2000 international units per day among inactive patients with inflammatory bowel disease, and between 5000 to 10 000 international units per day among those in the active stage, shows potential benefits on the disease.

La enfermedad inflamatoria intestinal es un trastorno crónico caracterizado por presentar episodios de exacerbación y remisión, cuya incidencia mundial se ha incrementado en las últimas décadas. La vitamina D está implicada en la regulación inmunológica, mejora las funciones de la barrera y la microbiota intestinal. Estudios han observado que niveles altos de esta vitamina disminuye la incidencia de recidivas y mejora la evolución clínica de la enfermedad. El objetivo de esta revisión fue analizar la evidencia sobre la suplementación de vitamina D en pacientes adultos con enfermedad inflamatoria intestinal. Los estudios que administraron dosis menores a 2000 unidades internacionales al día de vitamina D en pacientes ambulatorios, no presentaron efectos beneficios. Por el contrario, los que suplementan niveles de 2000 unidades internacionales al día incrementaron los niveles séricos de esta vitamina y redujo la actividad de la enfermedad. En el caso de los sujetos con enfermedad activa, dosis de 5000 a 10 000 unidades internacionales al día redujeron la sintomatología clínica. Esta revisión apreció que la suplementación con vitamina D sobre 2000 unidades internacionales al día, en pacientes con enfermedad inflamatoria intestinal en etapa inactiva y entre 5000 a 10 000 unidades internacionales al día en etapa activa, muestra efectos positivos en el cuadro clínico de la patología.

Zinc Intake and Status and Risk of Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis.

Zinc could have a protective role against type 2 diabetes mellitus (T2DM). This systematic review and meta-analysis aimed to evaluate the association between dietary, supplementary, and total zinc intake, as well as serum/plasma and whole blood zinc concentration, and risk of T2DM. Observational studies, conducted on cases of incident diabetes or T2DM patients and healthy subjects that reported a measure of association between zinc exposure and T2DM, were selected. Random effects meta-analyses were applied to obtain combined results. Stratified meta-analyses and meta-regressions were executed to assess sources of heterogeneity, as well as the impact of covariates on the findings. From 12,136 publications, 16 studies were selected. The odds ratio (OR) for T2DM comparing the highest versus lowest zinc intake from diet was 0.87 (95% CI: 0.78-0.98). Nevertheless, no association between supplementary or total zinc intake from both diet and supplementation, and T2DM was observed. A direct relationship was found between serum/plasma zinc levels and T2DM (OR = 1.64, 95% CI: 1.25-2.14). A moderately high dietary zinc intake, in relation to the Dietary Reference Intake, could reduce by 13% the risk of T2DM, and up to 41% in rural areas. Conversely, elevated serum/plasma zinc concentration was associated with an increased risk of T2DM by 64%, suggesting disturbances in zinc homeostasis.

Role of ethnicity and environment on lifestyle and cardiometabolic profile in the Native American Mapuche population: Protocol for a systematic review and meta-analysis.

INTRODUCTION: Cardiometabolic risk factors contribute to increase the incidence of some of the most widespread noncommunicable diseases today. The propensity to present an elevated cardiometabolic risk appears to especially affect non-Caucasians ethnic groups, such as the Native American Mapuche population. In addition, urbanization process has also a great impact on lifestyle and cardiometabolic profile. Therefore, a systematic review and meta-analysis will be conducted to summarize the relevant evidence regarding lifestyle and cardiometabolic profile in Mapuche population, and to assess the role of the ethnicity and the urbanization process on the lifestyle and cardiometabolic profile in Mapuche people with respect to European descendants. METHODS: A comprehensive search until 2019 will be performed using PubMed/MEDLINE, SciELO, Web of Science and Scopus. Observational studies, carried out in general population of Mapuche ethnicity living in rural and urban areas, with data of lifestyle and/or cardiometabolic profile, will be selected. A qualitative summary, as well as meta-analyzes when possible, will be done to present the information. Random effects meta-analyzes will be performed using the generic inverse variance method. Pooled effect size will be expressed as mean difference with 95% confidence intervals. Heterogeneity will be assessed using the Cochran Q-statistic and the I statistic. Stratified analyzes, meta-regressions, and sensitivity analyzes will be performed to evaluate potential sources of heterogeneity. In addition, random effects meta-regressions and stratified analyzes will also be used to examine the impact of covariates on the effect size estimated. Publication bias will be investigated using Egger and Begg test, and risk of bias will be assessed using the Research Triangle Institute Item Bank (RTI-IB). Finally, the quality of evidence will be evaluated through the Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidelines. RESULTS: The results of meta-analyzes will provide important information about differences in lifestyle and cardiometabolic profile between Mapuche people and European descendants, as well as between Mapuche people living in urban and rural areas. CONCLUSION: This systematic review and meta-analysis will be helpful to obtain a more reliable understanding of lifestyle and cardiometabolic profile in Mapuche population compared to European descendants, and the impact of the transition from rural to urban areas in this ethnic group.

Dietary zinc intake and whole blood zinc concentration in subjects with type 2 diabetes versus healthy subjects: A systematic review, meta-analysis and meta-regression.

The aim of this systematic review, meta-analysis and meta-regression was to examine the relationship between type 2 diabetes mellitus (T2DM) and concentration of zinc in whole blood, as well as dietary zinc intake. Searches were performed using Ovid MEDLINE, Embase (Ovid) and The Cochrane Library (CENTRAL). Observational studies conducted on diabetic and healthy adults, with data on dietary zinc intake and/or concentration of zinc in whole blood, were selected. The search strategy yielded 11,150 publications and the manual search 6, of which 11 were included in the meta-analyses. Mean difference (MD) and 95% confidence interval (CI), were calculated using the generic inverse-variance method with random-effects models. Heterogeneity was assessed by the Cochran Q-statistic and quantified by the I2 statistic. Meta-regressions and stratified analysis were used to examine whether any covariate had influence on the results. The pooled MD for the dietary zinc intake meta-analysis was -0.40 (95% CI: -1.59 to 0.79; I2 = 61.0%). Differences between diabetic and non-diabetic subjects became significant in the presence of complications associated with diabetes (MD = -2.26; 95% CI: -3.49 to -1.02; I2 = 11.9%). Meta-regression showed that for each year since the diagnosis of diabetes the concentration of zinc in whole blood decreased in diabetic patients regarding healthy controls [MD (concentration of zinc in blood) = 732.61 + (-77.88303) × (duration of diabetes in years)], which is not generally explained by a lower intake of zinc.