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Advances in Nutrition (Bethesda, Md.) May 2019Milk and dairy products contribute ≤14% of the caloric intake in developed countries. Recent evidence has shown controversial results with regard to the role of dairy...
Milk and dairy products contribute ≤14% of the caloric intake in developed countries. Recent evidence has shown controversial results with regard to the role of dairy products in deleterious processes such as inflammation. The increasing number of studies on the anti- and proinflammatory effects of milk and dairy products in the past 5 y reflects the growing interest in this area of research. The aim of this systematic review was to evaluate the scientific evidence provided in the past 5 y on the effects of milk and dairy products on inflammatory biomarkers provided by randomized clinical trials. The search strategy was conducted in Medline (via PubMed) and Scopus (which includes EMBASE and the Web of Science) databases and included articles from 1 January 2012 to 30 April 2018. The risk of bias was assessed using the Cochrane methodology. The number of study participants, type of study, doses, and the key results are reported. The following primary outcomes were considered for inclusion: circulating concentrations of C-reactive protein, interleukins, cytokines, and vascular adhesion molecules or expression of proinflammatory genes in peripheral blood mononuclear cells; however, the primary outcomes considered were not limited to these. Sixteen studies (15 articles) included in this systematic review reported on healthy individuals and subjects who were overweight or obese and who had metabolic syndrome or type 2 diabetes. The consumption of milk or dairy products did not show a proinflammatory effect in healthy subjects or individuals with metabolic abnormalities. The majority of studies documented a significant anti-inflammatory effect in both healthy and metabolically abnormal subjects, although not all the articles were of high quality. This review was registered on PROSPERO (International Prospective Register of Systematic Reviews) at https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=94535 as CRD42018094535.
Topics: Animals; Anti-Inflammatory Agents; Biomarkers; Dairy Products; Diabetes Mellitus, Type 2; Diet; Feeding Behavior; Humans; Inflammation; Metabolic Syndrome; Milk; Obesity
PubMed: 31089732
DOI: 10.1093/advances/nmy072 -
Obesity Reviews : An Official Journal... Dec 2022The dose-response association between sedentary time and the risk of metabolic syndrome is unclear, which indicates an important knowledge gap in public health. The... (Meta-Analysis)
Meta-Analysis Review
The dose-response association between sedentary time and the risk of metabolic syndrome is unclear, which indicates an important knowledge gap in public health. The objective of this study was to determine the categorical and continuous dose-response associations between sedentary time and the risk of metabolic syndrome. A systematic literature search of English articles published in PubMed, CINHAL, Embase, and Web of Science Core Collection prior to June 2022 was conducted. All cohort and cross-sectional studies that examined the association between sedentary time and the risk of metabolic syndrome were considered, and duplicate and non-related studies were excluded. Data extraction using a standardized chart and quality assessment using two appraisal tools were also performed. Two independent reviewers were involved in these processes. In categorical meta-analyses, the pooled effect sizes for metabolic syndrome associated with different categories of sedentary time were calculated by comparing the highest and intermediate with the lowest categories. In continuous meta-analyses, the linear and nonlinear dose-response associations were estimated using generalized least squares and restricted cubic spline models, respectively. Data were collected and analyzed from March to June 2022. Four prospective cohort studies and 22 cross-sectional studies with 105,239 participants and 16,185 MetS cases were included in this study. In categorical analyses, both intermediate (median duration: 4.11 h/day; pooled OR: 1.17, 95% CI: 1.08-1.26, P < 0.001) and high levels (median duration: 7.26 h/day; pooled OR: 1.71, 95% CI: 1.43-2.04, P < 0.001) of total sedentary time were significantly associated with an increased risk of metabolic syndrome. Similarly, a significant association between screen time and the risk of metabolic syndrome was also found in intermediate (median duration: 2.22 h/day; pooled OR: 1.20, 95% CI: 1.10-1.32, P < 0.001) and high levels (median duration: 3.40 h/day; pooled OR: 1.63, 95% CI: 1.44-1.86, P < 0.001) of exposure. Of note, these associations were significantly stronger in women. Different patterns of the behavior-disease association were not observed in children, adolescents, and adults. The findings of continuous meta-analyses could not provide solid evidence for the linearity and nonlinearity of the behavior-disease association. This study demonstrated that long-time sedentary behavior was associated with a higher risk of MetS independent of physical activity and the patterns of association varied by gender instead of age. These findings have implications for future guideline recommendations on physical activity, sedentary behavior, and prevention of metabolic syndrome.
Topics: Child; Adolescent; Adult; Humans; Female; Sedentary Behavior; Metabolic Syndrome; Cross-Sectional Studies; Prospective Studies; Exercise
PubMed: 36261077
DOI: 10.1111/obr.13510 -
Molecular Metabolism May 2020Polycystic ovary syndrome (PCOS) is the most common endocrinopathy among reproductive age women. Although its cardinal manifestations include hyperandrogenism,...
BACKGROUND
Polycystic ovary syndrome (PCOS) is the most common endocrinopathy among reproductive age women. Although its cardinal manifestations include hyperandrogenism, oligo/anovulation, and/or polycystic ovarian morphology, PCOS women often display also notable metabolic comorbidities. An array of pathogenic mechanisms have been implicated in the etiology of this heterogeneous endocrine disorder; hyperandrogenism at various developmental periods is proposed as a major driver of the metabolic and reproductive perturbations associated with PCOS. However, the current understanding of the pathophysiology of PCOS-associated metabolic disease is incomplete, and therapeutic strategies used to manage this syndrome's metabolic complications remain limited.
SCOPE OF REVIEW
This study is a systematic review of the potential etiopathogenic mechanisms of metabolic dysfunction frequently associated with PCOS, with special emphasis on the metabolic impact of androgen excess on different metabolic tissues and the brain. We also briefly summarize the therapeutic approaches currently available to manage metabolic perturbations linked to PCOS, highlighting current weaknesses and future directions.
MAJOR CONCLUSIONS
Androgen excess plays a prominent role in the development of metabolic disturbances associated with PCOS, with a discernible impact on key peripheral metabolic tissues, including the adipose, liver, pancreas, and muscle, and very prominently the brain, contributing to the constellation of metabolic complications of PCOS, from obesity to insulin resistance. However, the current understanding of the pathogenic roles of hyperandrogenism in metabolic dysfunction of PCOS and the underlying mechanisms remain largely incomplete. In addition, the development of more efficient, even personalized therapeutic strategies for the metabolic management of PCOS patients persists as an unmet need that will certainly benefit from a better comprehension of the molecular basis of this heterogeneous syndrome.
Topics: Adipose Tissue; Androgens; Animals; Bariatric Surgery; Female; Humans; Hyperandrogenism; Insulin Resistance; Metabolic Syndrome; Mice; Obesity; Polycystic Ovary Syndrome
PubMed: 32244180
DOI: 10.1016/j.molmet.2020.01.001 -
Obesity Reviews : An Official Journal... Feb 2019Women with polycystic ovary syndrome (PCOS) have increased risk of metabolic syndrome. The relative contribution of clinical, demographic or biochemical factors to... (Meta-Analysis)
Meta-Analysis
Women with polycystic ovary syndrome (PCOS) have increased risk of metabolic syndrome. The relative contribution of clinical, demographic or biochemical factors to metabolic syndrome in PCOS is not known. A literature search was conducted in MEDLINE, CINAHL, EMBASE and clinical trial registries. Of 4530 studies reviewed, 59 were included in the systematic review and 27 in the meta-analysis and meta-regression. In good and fair quality studies, women with PCOS had an overall increased prevalence of metabolic syndrome (odds ratio, OR 3.35, 95% confidence interval, CI 2.44, 4.59). Increased prevalence of metabolic syndrome occurred in overweight or obese women with PCOS (OR 1.88, 95% 1.16, 3.04) but not in lean women (OR 1.45, 95% CI 0.35, 6.12). In meta-regression analyses, the markers of metabolic syndrome diagnostic criteria (waist circumference, high-density lipoprotein cholesterol, triglyceride, blood pressure), BMI, glucose tolerance (2-hr oral glucose tolerance test) and surrogate markers of insulin resistance (HOMA-IR) but not markers of reproductive dysfunction (sex hormone binding globulin, testosterone, PCOS phenotypes) contributed significantly to the heterogeneity in the prevalence of metabolic syndrome. Women with PCOS have increased risk of metabolic syndrome which was associated with obesity and metabolic features but not with indices of hyperandrogenism.
Topics: Blood Glucose; Body Mass Index; Female; Humans; Insulin Resistance; Metabolic Syndrome; Polycystic Ovary Syndrome
PubMed: 30339316
DOI: 10.1111/obr.12762 -
The Lancet. Child & Adolescent Health Mar 2022Halting the rise in cardiometabolic risk factors in children and adolescents is crucial to curb the global burden of cardiovascular diseases. We aim to provide global,...
BACKGROUND
Halting the rise in cardiometabolic risk factors in children and adolescents is crucial to curb the global burden of cardiovascular diseases. We aim to provide global, regional, and national estimates of the prevalence of metabolic syndrome in children and adolescents to support the development of evidence-based prevention strategies.
METHODS
In this systematic review with modelling analysis, we searched PubMed, Embase, Africa Journal Online, and Global Index Medicus from database inception to Jan 30, 2021, with no restriction on language or geographical location. We included community-based and school-based cross-sectional studies and cross-sectional analysis of cohort studies that reported prevalence of metabolic syndrome in the general population of children (6-12 years) and adolescents (13-18 years). Only studies with a low risk of bias were considered. Eligible studies included at least 200 participants and used probabilistic-based sampling. Diagnosis of metabolic syndrome had to meet at least three of the following criteria: high systolic or diastolic blood pressure (≥90th percentile for age, sex, and height); waist circumference in at least the 90th percentile for age, sex, and ethnic group; fasting plasma glucose 5·6 mmol/L or greater; fasting plasma triglycerides 1·24 mmol/L or greater; and fasting plasma high density lipoprotein cholesterol 1·03 mmol/L or less. Independent investigators selected eligible studies and extracted relevant data. The primary outcome was a crude estimate of metabolic syndrome prevalence, assessed using a Bayesian hierarchical model.
FINDINGS
Our search yielded 6808 items, of which 169 studies were eligible for analysis, including 306 prevalence datapoints, with 550 405 children and adolescents from 44 countries in 13 regions. The between-study variance (τ) was 0·52 (95% CI 0·42-0·67), which could reflect the measurement of each component of the metabolic syndrome and covariates as sources of between-study heterogeneity. We estimated the global prevalence of metabolic syndrome in 2020 at 2·8% (95% uncertainty interval [UI] 1·4-6·7) for children and 4·8% (2·9-8·5) for adolescents, equating to around 25·8 (12·6-61·0) million children and 35·5 (21·3-63·0) million adolescents living with metabolic syndrome. In children, the prevalence of metabolic syndrome was 2·2% (95% UI 1·4-3·6) in high-income countries, 3·1% (2·5-4·3) in upper-middle-income countries, 2·6% (0·9-8·3) in lower-middle-income countries, and 3·5% (1·0-8·0) in low-income countries. In adolescents, the prevalence of metabolic syndrome was 5·5% (4·1-8·4) in high-income countries, 3·9% (3·1-5·4) in upper-middle-income countries, 4·5% (2·6-8·4) in lower-middle-income countries, and 7·0% (2·4-15·7) in low-income countries. Prevalence in children varied from 1·4% (0·6-3·1) in northwestern Europe to 8·2% (6·9-10·1) in Central Latin America. Prevalence for adolescents ranged from 2·9% (95% UI 2·6-3·3) in east Asia to 6·7% (5·9-8·3) in high-income English-speaking countries. The three countries with the highest prevalence estimates in children were Nicaragua (5·2%, 2·8-10·4), Iran (8·8%, 8·0-9·6), and Mexico (12·3%, 11·0-13·7); and the three countries with the highest prevalence estimates in adolescents were Iran (9·0%, 8·4-9·7), United Arab Emirates (9·8%, 8·5-10·3), and Spain (9·9%, 9·1-10·8).
INTERPRETATION
In 2020, about 3% of children and 5% of adolescents had metabolic syndrome, with some variation across countries and regions. The prevalence of metabolic syndrome was not consistently higher with increasing level of development, suggesting that the problem is not mainly driven by country wealth. The high number of children and adolescents living with metabolic syndrome globally highlights the urgent need for multisectoral interventions to reduce the global burden of metabolic syndrome and the conditions that lead to it, including childhood overweight and obesity.
FUNDING
None.
Topics: Adolescent; Age Distribution; Child; Cross-Sectional Studies; Female; Global Health; Humans; Male; Metabolic Syndrome; Models, Statistical; Prevalence
PubMed: 35051409
DOI: 10.1016/S2352-4642(21)00374-6 -
Reviews in Cardiovascular Medicine Dec 2021This study examines the effects of aerobic, resistance, and combined exercise on metabolic syndrome parameters and cardiovascular risk factors, to identify the most... (Meta-Analysis)
Meta-Analysis
This study examines the effects of aerobic, resistance, and combined exercise on metabolic syndrome parameters and cardiovascular risk factors, to identify the most effective way of improving metabolic syndrome and preventing cardiovascular disease. We searched EMBASE, the Cochrane Library, PubMed, MEDLINE, Ovid, the Chinese Biological Medicine Database (CBM), the Wanfang Database, the China National Knowledge Infrastructure (CNKI) database, and the Chinese Scientific Journal Database (VIP), for randomized controlled trials (RCTs), identifying 15 comparing the effects of aerobic, resistance, and combined exercise on metabolic syndrome parameters and cardiovascular risk factors (e.g., glucose, triglyceride, blood pressure, body mass index, etc.). We assessed the quality of the articles and performed a network meta-analysis with a Bayesian random effects model to synthesize direct and indirect evidence. Combined exercise was most effective at controlling glucose and total triglyceride (TG) levels. Aerobic, resistance, and combined exercise groups achieved significant effects regarding body fat. Aerobic exercise was superior to resistance exercise regarding body mass index (BMI). There was no statistically significant difference in weight, waist circumference (WC), levels of high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), insulin, systolic blood pressure (SBP), and diastolic blood pressure (DBP) among the exercise groups. Combined exercise was the best exercise scheme for improving weight, WC, DBP, TG, TC, glucose, and insulin levels. Resistance exercise was most effective at ameliorating body fat, LDL-C levels, and SBP. Aerobic exercise was the optimal way of improving BMI and HDL-C levels. This network meta-analysis suggests combined exercise is the most effective choice in improving the metabolic syndrome and cardiovascular risk parameters, whereas aerobic exercise reveals the minimum effect. Further studies should certify the role resistance exercises play in metabolic syndrome and cardiac rehabilitation.
Topics: Cholesterol, HDL; Exercise; Humans; Metabolic Syndrome; Network Meta-Analysis; Risk Factors; Waist Circumference
PubMed: 34957791
DOI: 10.31083/j.rcm2204156 -
Obesity Reviews : An Official Journal... Oct 2022Shift work, defined as work occurring outside typical daytime working hours, is associated with an increased risk for metabolic syndrome (MetS) due to several biological... (Meta-Analysis)
Meta-Analysis Review
Shift work, defined as work occurring outside typical daytime working hours, is associated with an increased risk for metabolic syndrome (MetS) due to several biological and environmental changes. The MetS refers to the clustering of several known cardiovascular risk factors, including insulin resistance, obesity, dyslipidemia, and hypertension. This systematic review aims to evaluate the literature on the association between shift work and the risk of MetS in employees of the health sector. A systematic search was conducted in PubMed, Web of Science, and Scopus databases using appropriate keywords for studies published before September 1, 2021. Eligible studies were those that compared the prevalence of MetS between day and shift healthcare workers; had a cross-sectional, case-control, or cohort study design; provided sufficient data for calculating odds ratios or relative risks with 95% confidence intervals; and articles in English. The Joanna Briggs Institute prevalence critical appraisal tool was used for quality analysis. Risk for MetS and related measures of effect size were retrieved from studies for meta-analysis. Twelve studies met the criteria for inclusion in the review and meta-analysis. Sample sizes ranged from 42 to 738, and the age range of subjects was between 18 and 65 years. Ten studies demonstrated high methodological quality, while two studies were of average quality. Ten out of 12 studies in the review demonstrated a higher risk in shift workers for developing MetS than day workers. The pooled OR of MetS in shift workers based on 12 studies was 2.17 (95% CI = 1.31-3.60, P = 0.003; I = 82%, P < 0.001). Shift workers exhibited more than a twofold increase in the chance of developing MetS in comparison with day workers.
Topics: Adolescent; Adult; Aged; Cohort Studies; Cross-Sectional Studies; Health Personnel; Humans; Metabolic Syndrome; Middle Aged; Shift Work Schedule; Young Adult
PubMed: 35734805
DOI: 10.1111/obr.13489 -
Fertility and Sterility Dec 2023The impact of paternal obesity and metabolic disease on semen quality and fertility outcomes is not fully appreciated. With increasing obesity rates, researchers have... (Review)
Review
The impact of paternal obesity and metabolic disease on semen quality and fertility outcomes is not fully appreciated. With increasing obesity rates, researchers have studied the intricate relationship between paternal body mass index, metabolic health, and male fertility. This systematic review identified 112 articles in the MEDLINE database between 2013 and 2023 that investigated the effects of body mass index, diabetes, metabolic syndrome, exercise, weight loss medication, or bariatric surgery on semen parameters, sperm quality, or fertility outcomes. This review suggests that obesity, diabetes, and metabolic syndrome have a negative impact on various parameters of male fertility, from semen quality to sperm deoxyribonucleic acid integrity. There is also mounting evidence that male obesity is correlated negatively with live births via both natural conception and assisted reproductive technologies. Lifestyle interventions, such as physical exercise, generally appear to improve male fertility markers; however, the type and intensity of exercise may play a crucial role. Pharmacologic treatments for weight loss, such as metformin and glucagon-like peptide 1 agonists, present a more complex picture, with studies suggesting both beneficial and detrimental effects on male reproductive health. Similarly, surgical interventions, such as gastric bypass surgery, show promise in improving hormonal imbalances but have mixed effects on semen parameters. Future research is needed to clarify these associations and inform clinical guidelines. In the interim, health practitioners should incorporate these insights into clinical practices, encouraging proactive lifestyle changes and providing targeted treatments to improve male reproductive health.
Topics: Male; Humans; Semen Analysis; Semen; Metabolic Syndrome; Obesity; Infertility, Male; Fertility; Weight Loss; Diabetes Mellitus
PubMed: 37839720
DOI: 10.1016/j.fertnstert.2023.10.017 -
BMC Public Health Apr 2016Metabolic syndrome (MS) comprises a set of conditions that are risk factors for cardiovascular diseases and diabetes. Numerous epidemiological studies on MS have been... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Metabolic syndrome (MS) comprises a set of conditions that are risk factors for cardiovascular diseases and diabetes. Numerous epidemiological studies on MS have been conducted, but there has not been a systematic analysis of the prevalence of MS in the Chinese population. Therefore, the aim of this study was to estimate the pooled prevalence of MS among subjects in Mainland China.
METHODS
We performed a systematic review by searching both English and Chinese literature databases. Random or fixed effects models were used to summarize the prevalence of MS according to statistical tests for heterogeneity. Subgroup, sensitivity, and meta-regression analyses were performed to address heterogeneity. Publication bias was evaluated using Egger's test.
RESULTS
Thirty-five papers were included in the meta-analysis, with a total population of 226,653 Chinese subjects. Among subjects aged 15 years and older, the pooled prevalence was 24.5% (95% CI: 22.0-26.9%). By sex, the prevalences were 19.2% (95% CI: 16.9-21.6%) in males and 27.0% (95% CI: 23.5-30.5%) in females. The pooled prevalence of MS increased with age (15-39 years: 13.9%; 40-59 years: 26.4%; and 60 years: 32.4%). Individuals living in urban areas (24.9%, 95% CI: 18.5-31.3%) were more likely to suffer from MS than those living in rural areas (19.2%, 95% CI: 14.8-23.7%). Hypertension was the most prevalent component of MS in males (52.8%), while the most prevalent component of MS for females was central obesity (46.1%).
CONCLUSIONS
Our systematic review suggested a high prevalence of MS among subjects in Mainland China, indicating that MS is a serious public health problem. Therefore, more attention should be paid to the prevention and control of MS.
Topics: Age Distribution; China; Humans; Metabolic Syndrome; Prevalence; Risk Factors; Sex Distribution
PubMed: 27039079
DOI: 10.1186/s12889-016-2870-y -
Nutrients Oct 2020The Mediterranean diet (MD) may provide metabolic benefits but no systematic review to date has examined its effect on a multitude of outcomes related to metabolic... (Meta-Analysis)
Meta-Analysis
The Mediterranean diet (MD) may provide metabolic benefits but no systematic review to date has examined its effect on a multitude of outcomes related to metabolic health. This systematic review with meta-analysis (International Prospective Register of Systematic Reviews, PROSPERO; number CRD42019141459) aimed to examine the MD's effect on metabolic syndrome (MetSyn) incidence, components and risk factors (primary outcomes), and incidence and/or mortality from MetSyn-related comorbidities and receipt of pharmacologic treatment for MetSyn components and comorbidities (secondary outcomes). We searched Pubmed, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Web of Science for controlled trials published until June 2019, comparing the MD with no treatment, usual care, or different diets in adults. Studies not published in English and not promoting the whole MD were excluded. Two authors independently extracted data and assessed risk of bias using the Cochrane Collaboration's and Risk of Bias in non-randomised studies (ROBINS-I) tools. Reporting followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Random-effects meta-analyses, subgroup analyses and meta-regressions were performed, and heterogeneity was quantified using the I statistic. We identified 2654 reports and included 84 articles reporting 57 trials ( = 36,983). In random effects meta-analyses, the MD resulted in greater beneficial changes in 18 of 28 MetSyn components and risk factors (body weight, body mass index, waist circumference, systolic and diastolic blood pressure, glucose, insulin, homeostatic model assessment of insulin resistance (HOMA-IR) index, total-, low-density lipoprotein (LDL)- and high-density lipoprotein (HDL)-cholesterol, triglycerides, alanine transaminase, hepatic fat mass, C-reactive protein, interleukin-6, tumour necrosis factor-a, and flow-mediated dilatation) and lower risk of cardiovascular disease incidence (risk ratio (RR) = 0.61, 95% confidence intervals (CI) 0.42-0.80; I = 0%), and stroke (RR = 0.67, 95% CI 0.35-0.98; I = 0%). Only six studies reported effects on pharmacotherapy use, and pooled analysis indicated no differences between diet groups. Lack of consistency in comparator groups and other study characteristics across studies resulted in high heterogeneity for some outcomes, which could not be considerably explained by meta-regressions. However, a consistent direction of beneficial effect of the MD was observed for the vast majority of outcomes examined. Findings support MD's beneficial effect on all components and most risk factors of the MetSyn, in addition to cardiovascular disease and stroke incidence. More studies are needed to establish effects on other clinical outcomes and use of pharmacotherapy for MetSyn components and comorbidities. Despite the high levels of heterogeneity for some outcomes, this meta-analysis enabled the comparison of findings across studies and the examination of consistency of effects. The consistent direction of effect, suggesting the MD's benefits on metabolic health, supports the need to promote this dietary pattern to adult populations.
Topics: Adult; Biomarkers; Blood Pressure; Comorbidity; Controlled Clinical Trials as Topic; Diet, Mediterranean; Health; Humans; Incidence; Insulin Resistance; Metabolic Syndrome; Metabolism; Oxidative Stress; Risk Factors
PubMed: 33143083
DOI: 10.3390/nu12113342