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Journal of Neurology, Neurosurgery, and... Nov 2020Evidence on preventing Alzheimer's disease (AD) is challenging to interpret due to varying study designs with heterogeneous endpoints and credibility. We completed a... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Evidence on preventing Alzheimer's disease (AD) is challenging to interpret due to varying study designs with heterogeneous endpoints and credibility. We completed a systematic review and meta-analysis of current evidence with prospective designs to propose evidence-based suggestions on AD prevention.
METHODS
Electronic databases and relevant websites were searched from inception to 1 March 2019. Both observational prospective studies (OPSs) and randomised controlled trials (RCTs) were included. The multivariable-adjusted effect estimates were pooled by random-effects models, with credibility assessment according to its risk of bias, inconsistency and imprecision. Levels of evidence and classes of suggestions were summarised.
RESULTS
A total of 44 676 reports were identified, and 243 OPSs and 153 RCTs were eligible for analysis after exclusion based on pre-decided criteria, from which 104 modifiable factors and 11 interventions were included in the meta-analyses. Twenty-one suggestions are proposed based on the consolidated evidence, with Class I suggestions targeting 19 factors: 10 with Level A strong evidence (education, cognitive activity, high body mass index in latelife, hyperhomocysteinaemia, depression, stress, diabetes, head trauma, hypertension in midlife and orthostatic hypotension) and 9 with Level B weaker evidence (obesity in midlife, weight loss in late life, physical exercise, smoking, sleep, cerebrovascular disease, frailty, atrial fibrillation and vitamin C). In contrast, two interventions are not recommended: oestrogen replacement therapy (Level A2) and acetylcholinesterase inhibitors (Level B).
INTERPRETATION
Evidence-based suggestions are proposed, offering clinicians and stakeholders current guidance for the prevention of AD.
Topics: Alzheimer Disease; Antihypertensive Agents; Cognition; Craniocerebral Trauma; Depression; Diabetes Mellitus; Education; Evidence-Based Medicine; Exercise; Humans; Hyperhomocysteinemia; Hypertension; Hypotension, Orthostatic; Life Style; Obesity; Observational Studies as Topic; Randomized Controlled Trials as Topic; Risk Reduction Behavior; Stress, Psychological
PubMed: 32690803
DOI: 10.1136/jnnp-2019-321913 -
Clinical Gastroenterology and... Jun 2018Celiac disease is a major public health problem worldwide. Although initially it was reported from countries with predominant Caucasian populations, it now has been... (Meta-Analysis)
Meta-Analysis
BACKGROUND & AIMS
Celiac disease is a major public health problem worldwide. Although initially it was reported from countries with predominant Caucasian populations, it now has been reported from other parts of the world. The exact global prevalence of celiac disease is not known. We conducted a systematic review and meta-analysis to estimate the global prevalence of celiac disease.
METHODS
We searched Medline, PubMed, and EMBASE for the keywords celiac disease, celiac, celiac disease, tissue transglutaminase antibody, anti-endomysium antibody, endomysial antibody, and prevalence for studies published from January 1991 through March 2016. Each article was cross-referenced with the words Asia, Europe, Africa, South America, North America, and Australia. The diagnosis of celiac disease was based on European Society of Pediatric Gastroenterology, Hepatology, and Nutrition guidelines. Of 3843 articles, 96 articles were included in the final analysis.
RESULTS
The pooled global prevalence of celiac disease was 1.4% (95% confidence interval, 1.1%-1.7%) in 275,818 individuals, based on positive results from tests for anti-tissue transglutaminase and/or anti-endomysial antibodies (called seroprevalence). The pooled global prevalence of biopsy-confirmed celiac disease was 0.7% (95% confidence interval, 0.5%-0.9%) in 138,792 individuals. The prevalence values for celiac disease were 0.4% in South America, 0.5% in Africa and North America, 0.6% in Asia, and 0.8% in Europe and Oceania; the prevalence was higher in female vs male individuals (0.6% vs 0.4%; P < .001). The prevalence of celiac disease was significantly greater in children than adults (0.9% vs 0.5%; P < .001).
CONCLUSIONS
In a systematic review and meta-analysis, we found celiac disease to be reported worldwide. The prevalence of celiac disease based on serologic test results is 1.4% and based on biopsy results is 0.7%. The prevalence of celiac disease varies with sex, age, and location. There is a need for population-based prevalence studies in many countries.
Topics: Adolescent; Adult; Aged; Autoantibodies; Celiac Disease; Child; Child, Preschool; Female; Global Health; Humans; Infant; Intestines; Male; Middle Aged; Prevalence; Young Adult
PubMed: 29551598
DOI: 10.1016/j.cgh.2017.06.037 -
Pharmaceuticals (Basel, Switzerland) Mar 2021Levothyroxine (l-thyroxine, l-T4) is a drug of choice for treating congenital and primary hypothyroidism. Although clinically significant interactions between l-T4 and... (Review)
Review
Levothyroxine (l-thyroxine, l-T4) is a drug of choice for treating congenital and primary hypothyroidism. Although clinically significant interactions between l-T4 and food can alter the safety and efficacy of the treatment, they still seem to be generally underestimated by patients, physicians and pharmacists. This review aimed to investigate the effects of meals, beverages, and dietary supplements consumption on l-T4 pharmacokinetics and pharmacodynamics, to identify the most evident interactions, and to perform the recommendations for safe co-administering of l-T4 and food. A total of 121 studies were identified following a systematic literature search adhering to PRISMA guidelines. After full-text evaluation, 63 studies were included. The results proved that l-T4 ingestion in the morning and at bedtime are equally effective, and also that the co-administration of l-T4 with food depends on the drug formulation. We found limited evidence for l-T4 interactions with coffee, soy products, fiber, calcium or iron supplements, and enteral nutrition but interestingly they all resulted in decreased l-T4 absorption. The altered l-T4 efficacy when ingested with milk, juices, papaya, aluminium-containing preparations, and chromium supplements, as well as observed enhancement effect of vitamin C on l-T4 absorption, shall be further investigated in larger, well-designed studies. Novel formulations are likely to solve the problem of coffee, calcium and iron induced malabsorption of l-T4. Maintaining a proper time interval between l-T4 and food intake, especially for coffee and calcium, or iron supplements, provides another effective method of eliminating such interactions.
PubMed: 33801406
DOI: 10.3390/ph14030206 -
Nutrients Sep 2023Both 25-autoimmunity and(25(OH)D: calcifediol) and its active form, 1,25-dihydroxyvitamin D (1,25(OH)D: calcitriol), play critical roles in protecting humans from... (Review)
Review
Both 25-autoimmunity and(25(OH)D: calcifediol) and its active form, 1,25-dihydroxyvitamin D (1,25(OH)D: calcitriol), play critical roles in protecting humans from invasive pathogens, reducing risks of autoimmunity, and maintaining health. Conversely, low 25(OH)D status increases susceptibility to infections and developing autoimmunity. This systematic review examines vitamin D's mechanisms and effects on enhancing innate and acquired immunity against microbes and preventing autoimmunity. The study evaluated the quality of evidence regarding biology, physiology, and aspects of human health on vitamin D related to infections and autoimmunity in peer-reviewed journal articles published in English. The search and analyses followed PRISMA guidelines. Data strongly suggested that maintaining serum 25(OH)D concentrations of more than 50 ng/mL is associated with significant risk reduction from viral and bacterial infections, sepsis, and autoimmunity. Most adequately powered, well-designed, randomized controlled trials with sufficient duration supported substantial benefits of vitamin D. Virtually all studies that failed to conclude benefits or were ambiguous had major study design errors. Treatment of vitamin D deficiency costs less than 0.01% of the cost of investigation of worsening comorbidities associated with hypovitaminosis D. Despite cost-benefits, the prevalence of vitamin D deficiency remains high worldwide. This was clear among those who died from COVID-19 in 2020/21-most had severe vitamin D deficiency. Yet, the lack of direction from health agencies and insurance companies on using vitamin D as an adjunct therapy is astonishing. Data confirmed that keeping an individual's serum 25(OH)D concentrations above 50 ng/mL (125 nmol/L) (and above 40 ng/mL in the population) reduces risks from community outbreaks, sepsis, and autoimmune disorders. Maintaining such concentrations in 97.5% of people is achievable through daily safe sun exposure (except in countries far from the equator during winter) or taking between 5000 and 8000 IU vitamin D supplements daily (average dose, for non-obese adults, ~70 to 90 IU/kg body weight). Those with gastrointestinal malabsorption, obesity, or on medications that increase the catabolism of vitamin D and a few other specific disorders require much higher intake. This systematic review evaluates non-classical actions of vitamin D, with particular emphasis on infection and autoimmunity related to the immune system.
Topics: Adult; Humans; Vitamin D; Autoimmunity; COVID-19; Immune System; Autoimmune Diseases; Vitamins; Vitamin D Deficiency
PubMed: 37686873
DOI: 10.3390/nu15173842 -
Alimentary Pharmacology & Therapeutics Aug 2017"Exercise-induced gastrointestinal syndrome" refers to disturbances of gastrointestinal integrity and function that are common features of strenuous exercise. (Review)
Review
BACKGROUND
"Exercise-induced gastrointestinal syndrome" refers to disturbances of gastrointestinal integrity and function that are common features of strenuous exercise.
AIM
To systematically review the literature to establish the impact of acute exercise on markers of gastrointestinal integrity and function in healthy populations and those with chronic gastrointestinal conditions.
METHODS
Search literature using five databases (PubMed, EBSCO, Web of Science, SPORTSdiscus, and Ovid Medline) to review publications that focused on the impact of acute exercise on markers of gastrointestinal injury, permeability, endotoxaemia, motility and malabsorption in healthy populations and populations with gastrointestinal diseases/disorders.
RESULTS
As exercise intensity and duration increases, there is considerable evidence for increases in indices of intestinal injury, permeability and endotoxaemia, together with impairment of gastric emptying, slowing of small intestinal transit and malabsorption. The addition of heat stress and running mode appears to exacerbate these markers of gastrointestinal disturbance. Exercise stress of ≥2 hours at 60% VO appears to be the threshold whereby significant gastrointestinal perturbations manifest, irrespective of fitness status. Gastrointestinal symptoms, referable to upper- and lower-gastrointestinal tract, are common and a limiting factor in prolonged strenuous exercise. While there is evidence for health benefits of moderate exercise in patients with inflammatory bowel disease or functional gastrointestinal disorders, the safety of more strenuous exercise has not been established.
CONCLUSIONS
Strenuous exercise has a major reversible impact on gastrointestinal integrity and function of healthy populations. The safety and health implications of prolonged strenuous exercise in patients with chronic gastrointestinal diseases/disorders, while hypothetically worrying, has not been elucidated and requires further investigation.
Topics: Biomarkers; Chronic Disease; Exercise; Gastric Emptying; Gastrointestinal Diseases; Humans; Intestinal Diseases; Intestine, Small; Permeability
PubMed: 28589631
DOI: 10.1111/apt.14157 -
Critical Reviews in Food Science and... 2019Over 60 percent of the human population has a reduced ability to digest lactose due to low levels of lactase enzyme activity. Probiotics are live bacteria or yeast that...
Over 60 percent of the human population has a reduced ability to digest lactose due to low levels of lactase enzyme activity. Probiotics are live bacteria or yeast that supplements the gastrointestinal flora. Studies have shown that probiotics exhibit various health beneficial properties such as improvement of intestinal health, enhancement of the immune responses, and reduction of serum cholesterol. Accumulating evidence has shown that probiotic bacteria in fermented and unfermented milk products can be used to alleviate the clinical symptoms of lactose intolerance (LI). In this systematic review, the effectiveness of probiotics in the treatment of LI was evaluated using 15 randomized double-blind studies. Eight probiotic strains with the greatest number of proven benefits were studied. Results showed varying degrees of efficacy but an overall positive relationship between probiotics and lactose intolerance.
Topics: Animals; Bacteria; Cholesterol; Databases, Factual; Dietary Supplements; Digestion; Double-Blind Method; Fatty Acids, Volatile; Fermentation; Gastrointestinal Microbiome; Humans; Lactose; Lactose Intolerance; Milk; Probiotics; Randomized Controlled Trials as Topic; Yeasts
PubMed: 29425071
DOI: 10.1080/10408398.2018.1425977 -
The Lancet. Gastroenterology &... Oct 2017Studies have shown wide variation in the prevalence of lactose malabsorption across the world, but no systematic reviews or meta-analyses have recently assessed the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Studies have shown wide variation in the prevalence of lactose malabsorption across the world, but no systematic reviews or meta-analyses have recently assessed the prevalence of lactose malabsorption in different geographical areas. We aimed to present an updated systematic review and meta-analysis on the prevalence of lactose malabsorption in adults, by countries and regions, and to assess the variation between different testing methods.
METHODS
Studies reporting on prevalence of lactose malabsorption and lactase persistence were identified by searching MEDLINE and Embase from database inception to Nov 2, 2016. We evaluated studies presenting lactose malabsorption or lactase persistence prevalence data in adults and children aged 10 years or older, including cross-sectional and prospective studies, using genotyping, hydrogen breath tests, lactose tolerance tests, and other testing methods. We excluded studies in children younger than 10 years, studies using self-reported data, and studies including inpatients and outpatients at gastroenterological wards. Studies were screened by two authors (CLS and SKF) and data values were extracted by two authors (CLS and SKF) independently. The primary outcome was the prevalence of lactose malabsorption. This study is registered with PROSPERO, number CRD42017064802.
FINDINGS
We screened 2665 records, and 306 study populations from 116 full-text articles were included (primary sources); data for 144 additional study populations from 59 articles were obtained from review articles, because full-text primary articles could not be obtained (secondary sources). Of the 450 study populations included, 231 were assessed by genotyping, 83 by hydrogen breath tests, 101 by lactose tolerance tests, and 35 by other methods or methods that were not described sufficiently. The studies included 62 910 participants from 89 countries (covering 84% of the world's population). When standardising for country size, the global prevalence estimate of lactose malabsorption was 68% (95% CI 64-72), ranging from 28% (19-37) in western, southern, and northern Europe to 70% (57-83) in the Middle East. When assessing the global prevalence using genotyping data only, the estimate was 74% (69-80), whereas prevalence was 55% (46-65) using lactose tolerance test data, and 57% (46-67) using hydrogen breath test data. Risk of bias was assessed based on ten indicators; 12 of the articles had a score of ten, indicating low risk of bias, 76 had a score of nine, 26 a score of eight, and two articles a score of seven (indicating higher risk of bias). There was substantial heterogeneity between studies within most of the assessed countries.
INTERPRETATION
Lactose malabsorption is widespread in most of the world, with wide variation between different regions and an overall frequency of around two-thirds of the world's population. Acknowledging regional patterns of lactose malabsorption is important to guide management of gastrointestinal symptoms.
FUNDING
None.
Topics: Adult; Breath Tests; Genotype; Global Burden of Disease; Humans; Lactose Intolerance; Lactose Tolerance Test; Prevalence
PubMed: 28690131
DOI: 10.1016/S2468-1253(17)30154-1 -
Nutrients May 2020Lactose intolerance (LI) is characterized by the presence of primarily gastrointestinal clinical signs resulting from colonic fermentation of lactose, the absorption of... (Meta-Analysis)
Meta-Analysis
Lactose intolerance (LI) is characterized by the presence of primarily gastrointestinal clinical signs resulting from colonic fermentation of lactose, the absorption of which is impaired due to a deficiency in the lactase enzyme. These clinical signs can be modified by several factors, including lactose dose, residual lactase expression, concurrent ingestion of other dietary components, gut-transit time, and enteric microbiome composition. In many of individuals with lactose malabsorption, clinical signs may be absent after consumption of normal amounts of milk or, in particular, dairy products (yogurt and cheese), which contain lactose partially digested by live bacteria. The intestinal microbiota can be modulated by biotic supplementation, which may alleviate the signs and symptoms of LI. This systematic review summarizes the available evidence on the influence of prebiotics and probiotics on lactase deficiency and LI. The literature search was conducted using the MEDLINE (via PUBMED) and SCOPUS databases following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and included randomized controlled trials. For each study selected, the risk of bias was assessed following the Cochrane Collaboration methodology. Our findings showed varying degrees of efficacy but an overall positive relationship between probiotics and LI in relation to specific strains and concentrations. Limitations regarding the wide heterogeneity between the studies included in this review should be taken into account. Only one study examined the benefits of prebiotic supplementation and LI. So further clinical trials are needed in order to gather more evidence.
Topics: Abdominal Pain; Animals; Databases, Factual; Diarrhea; Diet; Flatulence; Food, Fortified; Gastrointestinal Microbiome; Humans; Lactase; Lactose; Lactose Intolerance; Milk; Prebiotics; Probiotics; Vomiting
PubMed: 32443748
DOI: 10.3390/nu12051487 -
Nutrients Dec 2022The microbiota, as a complex of microorganisms in a particular ecosystem, is part of the wider term-microbiome, which is defined as the set of all genetic content in the... (Review)
Review
The microbiota, as a complex of microorganisms in a particular ecosystem, is part of the wider term-microbiome, which is defined as the set of all genetic content in the microbial community. Imbalanced gut microbiota has a great impact on the homeostasis of the organism. Dysbiosis, as a disturbance in bacterial balance, might trigger or exacerbate the course of different pathologies. Small intestinal bacterial overgrowth (SIBO) is a disorder characterized by differences in quantity, quality, and location of the small intestine microbiota. SIBO underlies symptoms associated with functional gastrointestinal disorders (FGD) as well as may alter the presentation of chronic diseases such as heart failure, diabetes, etc. In recent years there has been growing interest in the influence of SIBO and its impact on the whole human body as well as individual systems. Therefore, we aimed to investigate the co-existence of SIBO with different medical conditions. The PubMed database was searched up to July 2022 and we found 580 original studies; inclusion and exclusion criteria let us identify 112 eligible articles, which are quoted in this paper. The present SIBO diagnostic methods could be divided into two groups-invasive, the gold standard-small intestine aspirate culture, and non-invasive, breath tests (BT). Over the years scientists have explored SIBO and its associations with other diseases. Its role has been confirmed not only in gastroenterology but also in cardiology, endocrinology, neurology, rheumatology, and nephrology. Antibiotic therapy could reduce SIBO occurrence resulting not only in the relief of FGD symptoms but also manifestations of comorbid diseases. Although more research is needed, the link between SIBO and other diseases is an important pathway for scientists to follow.
Topics: Humans; Intestine, Small; Anti-Bacterial Agents; Blind Loop Syndrome; Irritable Bowel Syndrome; Microbiota; Breath Tests
PubMed: 36615748
DOI: 10.3390/nu15010090 -
Frontiers in Endocrinology 2023Hashimoto's thyroiditis (HT) is the most common autoimmune disease. HT may be associated with nonthyroidal autoimmune diseases, including celiac disease (CD) or other... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Hashimoto's thyroiditis (HT) is the most common autoimmune disease. HT may be associated with nonthyroidal autoimmune diseases, including celiac disease (CD) or other gluten-related conditions (GRC). In the last years, interest about gluten-free diet (GFD) has increased for its supposed extraintestinal anti-inflammatory effect; thus, many patients with HT initiate GFD on their own.
OBJECTIVES
The aim of this meta-analysis is to examine all available data in literature about the effect of a GFD on TgAb, TPOAb, TSH, FT4, and FT3 levels in patients with HT and no symptoms or histology of CD.
METHODS
The study was conducted according to MOOSE (Meta-analysis Of Observational Studies in Epidemiology). The search was performed on databases PubMed and Scopus. The last search was performed on 7 February 2023. Quality assessment was performed. Meta-analyses were performed using the random-effect model. Hedges' was used to measure the effect size (ES). Statistical analyses were performed using StataSE 17.
RESULTS
The online search retrieved 409 articles, and 4 studies with a total of 87 patients were finally included for quantitative analysis. The risk of bias was generally low. The mean period of GFD was almost 6 months. The meta-analyses showed reduction in antibody levels with ES: -0.39 for TgAb (95% CI: -0.81 to +0.02; = 0.06; ² = 46.98%) and -0.40 for TPOAb (95% CI: -0.82 to +0.03; = 0.07; ² = 47.58%). TSH showed a reduction with ES: -0.35 (95% CI: -0.64 to -0.05; = 0.02; ² = 0%) and FT4 showed an increase with ES: +0.35% (95% CI: 0.06 to 0.64; = 0.02; ² = 0%). FT3 did not display variations (ES: 0.05; 95% CI: -0.38 to +0.48; = 0.82; ² = 51%). The heterogeneity of TgAb, TPOAb, and FT3 data was solved performing sub-analyses between patients with or without GRC (TgAb = 0.02; TPOAb = 0.02; FT3 = 0.04) and only for FT3, performing a sub-analysis between patients taking and not taking LT4 ( = 0.03).
CONCLUSION
This is the first meta-analysis investigating the effect of GFD on HT. Our results seem to indicate a positive effect of the gluten deprivation on thyroid function and its inflammation, particularly in patients with HT and GRC. However, current lines of evidence are not yet sufficient to recommend this dietary approach to all patients with a diagnosis of HT.
Topics: Humans; Thyroiditis, Autoimmune; Diet, Gluten-Free; Celiac Disease; Autoantibodies; Hashimoto Disease; Thyrotropin
PubMed: 37554764
DOI: 10.3389/fendo.2023.1200372