Metabolic syndrome and risk of cardiovascular disease: a meta-analysis

Purpose

The use of different definitions of the metabolic syndrome has led to inconsistent results on the association between the metabolic syndrome and risk of cardiovascular disease. We examined the association between the metabolic syndrome and risk of cardiovascular disease.

Methods

A MEDLINE search (1966-April 2005) was conducted to identify prospective studies that examined the association between the metabolic syndrome and risk of cardiovascular disease. Information on sample size, participant characteristics, metabolic syndrome definition, follow-up duration, and endpoint assessment was abstracted.

Results

Data from 21 studies met the inclusion criteria and were included. Individuals with the metabolic syndrome, compared to those without, had an increased mortality from all causes (relative risk [RR] 1.35; 95% confidence interval [CI], 1.17-1.56) and cardiovascular disease (RR 1.74; 95% CI, 1.29-2.35); as well as an increased incidence of cardiovascular disease (RR 1.53; 95% CI, 1.26-1.87), coronary heart disease (RR 1.52; 95% CI, 1.37-1.69) and stroke (RR 1.76; 95% CI, 1.37-2.25). The relative risk of cardiovascular disease associated with the metabolic syndrome was higher in women compared with men and higher in studies that used the World Health Organization definition compared with studies that used the Adult Treatment Panel III definition.

Conclusion

This analysis strongly suggests that the metabolic syndrome is an important risk factor for cardiovascular disease incidence and mortality, as well as all-cause mortality. The detection, prevention, and treatment of the underlying risk factors of the metabolic syndrome should become an important approach for the reduction of the cardiovascular disease burden in the general population.     

Impact of metabolic and cardiovascular disease on COVID-19 mortality: A systematic review and meta-analysis

Background and aimsThis meta-analysis aims to highlight the impact of cardio-metabolic comorbidities on COVID-19 severity and mortality.MethodsA thorough search on major online databases was done for studies describing the clinical outcomes of COVID-19 patients. We used random-effects model to compute pooled estimates for critical or fatal disease.ResultsA total of 20,475 patients from 33 eligible studies were included. Maximum risk of development of critical or fatal COVID-19 disease was seen in patients with underlying cardiovascular disease [OR: 3.44, 95% CI: 2.65–4.48] followed by chronic lung disease, hypertension and diabetes mellitus. Of the total cases, 64% had one of the four comorbidities with the most prevalent being hypertension with a pooled prevalence of 27%.ConclusionsPresence of comorbidities like cardiovascular disease, chronic lung disease, hypertension and diabetes mellitus led to a higher risk of development of critical or fatal COVID-19 disease, with maximum risk seen with underlying cardiovascular disease.     

The benefits of yoga practice compared to physical exercise in the management of type 2 Diabetes Mellitus: A systematic review and meta-analysis

Yoga is increasingly used as an adjunctive therapy in the management of Type-2 Diabetes Mellitus (T2DM). The present study aims to systematically evaluate the literature and perform a meta-analysis on the effects of yoga practice compared to physical exercise in the management of T2DM. Data were obtained using a stepwise search process using keywords in the following online medical databases; PubMed, Web of Science and Scopus. All controlled clinical trials involving patients with T2DM, comparing yoga as an intervention with physical exercise and evaluating glycaemic control and other outcomes between the intervention and control groups were included in the analysis.Eight studies were eligible to be included in the systematic review. In total, 842 participants were assigned to a Yoga intervention or a control group with an Exercise intervention and the age range of participants was 30–78 years. A significant reduction in FBG (15.16?mg/dl), PPBG (28.66?mg/dl), HbA1c (0.39%) and BMI (0.71?kg/m2) was noted in the intervention group (‘Yoga’) compared to the control group (‘Physical Exercise’) in the pooled analysis. We did not observe any significant difference between the two groups for lipid parameters, other body composition measures (WC and WHR) and Blood Pressure. In conclusion, our results show that Yoga has beneficial effects on glycaemic control in comparison to physical exercise in T2DM However, individual studies showed considerable heterogeneity. Hence, further well-controlled randomized trials are required prior to drawing conclusions about the benefits of yoga in comparison to physical exercise.     

Association between shift work and risk of metabolic syndrome: A systematic review and meta-analysis

AimsA comprehensive assessment of the association of shift work with risk of metabolic syndrome (MetS) through a systematic review and meta-analysis has not been reported. We aimed to evaluate the relationship from observational studies.Data synthesisWe searched PubMed, Embase, and Web of Science databases from inception to December 16, 2020. Articles were chosen according to established inclusion criteria. Studies with data on men and women and different types of shift work were treated as independent studies. Relative risks (RRs) and 95% confidence intervals (CIs) were pooled by using random-effects models with heterogeneity (I²) > 50%; otherwise, a fixed-effects model was used. A total of 7192 articles was searched from PubMed, Embase and Web of science. Finally, we included 23 articles (38 studies) in this meta-analysis. The pooled RRs and 95% CI of MetS risk with shift work, 1-shift work, 2-shift work, and 3-shift work versus non-shift work were 1.30 (95% CI 1.19–1.41), 0.95 (95% CI 0.82–1.11), 1.19 (95% CI 0.91–1.56) and 1.17 (95% CI 1.00–1.37), respectively. The results from subgroup analyses stratified by sex, age, and region supported our overall findings that shift work is a risk factor for MetS.ConclusionsThis meta-analysis suggests that shift work increases risk of MetS. Higher risk of MetS was found in the shift workers who were 2-shift or 3-shift or women or Asian workers.     

Flow-mediated dilation and cardiovascular risk prediction: A systematic review with meta-analysis

Background

Flow-mediated dilation (FMD) is an accepted technique to quantify endothelial function and has shown to have prognostic value for future cardiovascular disease (CVD). The predictive strength of FMD in CVD patients compared to populations not diagnosed for CVD warrants further investigation. We systematically reviewed prospective studies that investigated the association between brachial FMD and future cardiovascular events, with particular focus on the role of underlying health status.

Methods

To obtain eligible studies, several literature databases were systematically searched through March 2011. Pooled overall risk estimates were calculated separately for continuous risk estimates for CVD (per 1% higher FMD) and for categorical risk estimates for CVD (having high vs. low FMD), based on random-effects models.

Results

A total of 23 studies including 14,753 subjects were eligible for inclusion in the meta-analysis. For studies reporting continuous risk estimates, the pooled overall CVD risk was 0.92 (95%CI: 0.88; 0.95) per 1% higher FMD. The observed association seemed stronger (P-value < 0.01) in diseased populations than in asymptomatic populations (0.87 (95%CI: 0.83; 0.92) and 0.96 (95%CI: 0.92; 1.00) per 1% higher FMD, respectively). For studies reporting categorical risk estimates, the pooled overall CVD risk for high vs. low FMD was similar in both types of populations, on average 0.49 (95%CI: 0.39; 0.62).

Conclusions

Our findings show that brachial FMD is inversely associated with future CVD events, with some indications for a stronger relation in diseased populations. Endothelial dysfunction may be considered relevant for classifying subjects in terms of CVD risk.     

Water intake and risk of type 2 diabetes: A systematic review and meta-analysis of observational studies

Background and aimsThe association of water intake with type 2 diabetes mellitus (T2DM) is still unclear. Therefore, the aim of this systematic review and meta-analysis was to synthesize the knowledge about the relationship between water intake and the risk of T2DM.MethodsWe conducted a systematic search in PubMed and Scopus up to June 2018 for observational studies. Risk ratios (RR)s and 95% confidence intervals (95% CI)s were calculated and fixed effects models were used.ResultsOverall, 6 studies were included in the meta-analyses. There was an inverse relationship between water intake and risk of T2DM (RR: 0.94; 95% CI: 0.91–0.97, P < 0.001) with low heterogeneity (I2 = 24%, P = 0.24).ConclusionOur findings indicated that the intake of water was correlated with reduced risk of type 2 diabetes in women and men. These results support the current recommendations of water intake as an inseparable part of a diet with the lowest risk of diabetes mellitus.     

Impact of metabolic syndrome criteria on cardiovascular disease risk in people with newly diagnosed type 2 diabetes

Aims/hypothesis We investigated the prognostic implication of metabolic syndrome according to modified National Cholesterol Education Program criteria and the implication of individual features of metabolic syndrome on cardiovascular disease (CVD) and CHD in a 5-year community-based study of people with newly diagnosed type 2 diabetes. Methods We entered 562 participants, aged 30–74 years, into a cross-sectional analysis and 428 participants (comprising those who were CVD-free at study entry) into a prospective analysis. In both analyses, the association of metabolic syndrome features with CVD/CHD was studied. Binary logistic regression, a Cox regression model and Fisher's exact test were used for statistical analyses. Results At diagnosis of type 2 diabetes, metabolic syndrome was independently associated with CVD (odds ratio [OR] 2.54; p=0.006) and CHD (OR 4.06; p=0.002). In the 5-year follow-up, metabolic syndrome at baseline was an independent predictor of incident CVD (hazard ratio [HR] 2.05; p=0.019). An increase in the number of individual features of the metabolic syndrome present at the time of diagnosis of type 2 diabetes was associated with a linear increase in incident CVD risk (trend p=0.044) with an almost five-fold increase when all five features were present, compared with hyperglycaemia alone (HR 4.76; p=0.042). Increasing age (HR 1.07; p<0.001), female sex (HR 0.62; p=0.032), total cholesterol (HR 1.43; p=0.01) and lipid-lowering therapy (HR 0.32; p<0.001) were also independent predictors of risk. Conclusions/interpretation Metabolic syndrome at baseline is associated with an increased risk of incident CVD in the 5 years following diagnosis of type 2 diabetes. CVD-free survival rates declined incrementally as the presence of metabolic syndrome features increased. Thus, identifying the features of metabolic syndrome at diagnosis of type 2 diabetes is potentially a useful prognostic tool for identifying individuals at increased risk of CVD.     

Socio-personal factors affecting adherence to treatment in patients with type 2 diabetes: A systematic review and meta-analysis

PurposeThe purpose of study was to identify the socio-personal factors affecting adherence to the treatment of patients with type 2 diabetes.MethodsCross-sectional articles were extracted from databases such as Web of Science, PubMed, Elsevier. A meta-analysis was performed using integrated odds ratios (OR) and 95% confidence interval (CIs) for age, BMI, depression, educational level, gender, employment status, marital status, smoking status. STATA 12.0 was used to estimate pooled RR in definite subgroups. The quality of the studies included was evaluated using the STROBE checklist.ResultsThirty-one studies out of 7407 extracted articles were finally selected for the meta-analysis. The results showed that younger people had a 17% higher risk than older people, smokers had a 22% higher risk than non-smokers, and the employed had a 15% higher risk of non-adherence to treatment.ConclusionIn conclusion, older age, smoking and employment can lead to non-adherence to T2D treatment. Interventions are suggested to be made besides common health care considering the socio-personal features on type 2 diabetes patients' treatment adherence.     

Metabolic syndrome among type 2 diabetic patients in Sub-Saharan African countries: A systematic review and meta-analysis

Background and aimsMetabolic syndrome is one of the serious public health problems among type 2 diabetic patients. Despite a number of studies have been conducted, there is no overall estimation on the prevalence of metabolic syndrome among type 2 diabetic patients in Sub-Saharan African countries. Therefore, this study aimed to estimate the pooled prevalence of metabolic syndrome in patients with type 2 diabetes mellitus in Sub –Saharan African countries.MethodsPubMed, Web of Science, African Journals Online, Google Scholar, Scopus, and Wiley Online Library databases from inception to April 27, 2020 were searched to identify relevant studies. The I² statistic was used to check heterogeneity across the included studies. DerSimonian and Laird random-effects model was applied to estimate pooled effect size, and 95% confidence interval across studies. A funnel plot and Egger’s regression test were used to determine the presence of publication bias. Sensitivity analysis was deployed to determine the effect of a single study on the overall estimation. All statistical analyses were done using STATA™ Version 14 software.ResultIn this meta-analysis, a total of 23 studies with 6482 study participants were included. The estimated prevalence of metabolic syndrome in Sub-Saharan African countries was 59.62% (95% CI: 52.20, 67.03). Based on the subgroup analysis, the highest prevalence of metabolic syndrome (61.14%, 95% CI: 51.74, 70.53) was reported in Ethiopia. Additionally, the highest prevalence of metabolic syndrome was reported across studies using the diagnostic criteria of National Cholesterol Education Program Adult Treatment Panel III 64.8% (95% CI: 54.74, 74.86), followed by International Diabetic Federation (57.15%), and World health Organization (53.12%) definitions.ConclusionAlmost two out of three type 2 diabetic patients in Sub-Saharan African countries have metabolic syndrome, which implies that its prevalence is high in patients with type 2 diabetes mellitus. Therefore, policymakers need to design efficient strategies and guideline to reduce and control the burden of metabolic syndrome and its impact among diabetic population.     

Metformin and risk of cancer among patients with type 2 diabetes mellitus: A systematic review and meta-analysis

AimWe carried out this meta-analysis on all published studies to estimate the overall cancer risk of the use of metformin in T2DM patients.MethodsWe searched the PubMed, Embase and CNKI databases for all articles within a range of published years from 2007 to 2019 on the association between the use of metformin and cancer risk in T2DM patients. The odds ratio (OR) corresponding to the 95% confidence interval (95% CI) was used to assess the association using a random-effect meta-analysis.ResultsFinally, 67 studies met the inclusion criteria for this study, with 10,695,875 T2DM patients and 145,108 cancer cases. Overall, For T2DM patients of ever vs. never metformin users, there was statistical evidence of significantly decreased cancer risk was found to be associated with ever metformin users (OR = 0.70, 95% CI = 0.65–0.76). Considering T2DM may be a specific and independent risk factor for various forms of cancer, due to its particular metabolic characteristics of glucose intolerance and hyperinsulinemia, we performed a comparison to estimate the effects of metformin on cancer risk with other anti-diabetes medications (ADMs), our results found significantly decreased cancer risk to be associated with the use of metformin (OR = 0.80, 95% CI = 0.73–0.87).ConclusionOur meta-analysis indicated that metformin may be a independent protective factor for cancer risk in T2DM patients.     

A systematic review and meta-analysis of the association between fish consumption and risk of metabolic syndrome

AimsResults regarding the association between fish intake and risk of metabolic syndrome (MetS) are ambiguous. Therefore, this study aims to evaluate whether there is an association between fish consumption and risk of MetS.Data synthesisA comprehensive literature search was conducted of PubMed, Embase, ScienceDirect and Google Scholar up to August 2019. A random-effects model was used to pool the risk of MetS in the highest category of fish consumption compared with the lowest one. Subgroup analysis was conducted based on country of region, gender, dietary tool, MetS definition, energy adjustment and sample size. A dose–response of analysis of fish intake and risk of MetS was also conducted. Twelve studies with a total of 16 effect sizes (10 cross-sectional and six cohort) were included. An inverse association was observed between fish intake and risk of MetS in cohort (OR = 0.80, 95% CI: 0.66, 0.96; P = 0.017, I² = 62.9%) but not cross-sectional studies (OR = 0.80, 95% CI: 0.70, 1.02; P = 0.085, I² = 50.1%). Subgroup analysis suggested that the results were influenced by all the included variables but sample size. A significant non-linear association was observed between fish intake levels and risk of MetS (P-value for non-linearity = 0.010).ConclusionAn inverse association existed between fish intake and risk of MetS when combining data from prospective cohort studies. Further studies are needed to confirm such an effect.     

Prevalence of the cardiovascular health status in adults: A systematic review and meta-analysis

Background and aims

The American Heart Association has outlined seven cardiovascular health (CVH) metrics, including smoking, body mass index, physical activity, dietary pattern, total cholesterol, and fasting plasma glucose, to define and monitor CVH status. Our study was to evaluate the global CVH in adults.

Triglyceride-glucose index predicts independently type 2 diabetes mellitus risk: A systematic review and meta-analysis of cohort studies

ObjectiveOur objective was to perform a systematic review and meta-analysis of cohort studies evaluating the triglyceride-glucose (TyG) index as a tool for type 2 diabetes (T2D) prediction in adults and older adults.MethodsStudies were identified in PubMed, Cochrane, Scopus, and Lilacs. Studies with cohort design, which evaluated the T2D incidence through the hazard ratio (HR) or relative risk (RR) or odds ratio values were included. Were included both studies that evaluated the incidence of T2D from tertiles, quartiles, quintiles, or single TyG index values. First, a meta-analysis only for studies that reported data in HR values was performed. Additionally, given the different association measurements used, the number of T2D cases, non-T2D cases, and the total number of participants were extracted from exposed and non-exposed groups when available. Then the risk ratio was calculated. A meta-analysis using the inverse variance method and the random-effects model was performed. Heterogeneity was assessed by I² statistics and by inspecting funnel plots.ResultsThirteen cohort studies with a total of 70,380 subjects, both sexes, adults, and older adults were included in the meta-analysis. Ten studies showed a significant association of the TyG index with T2D risk through HR estimative (overall HR: 2.44, 95% CI: 2.17–2.76). After estimating RR for nine studies, we also observed a significant association of the TyG index with T2D risk (RR: 3.12, 95 CI: 2.31–4.21). For all analyses, high heterogeneity was verified by I² and visual inspection of funnel plots.ConclusionsTyG index has a positive and significant association with T2D risk, suggesting that the TyG index may become an applicable tool to identify subjects with T2D risk. However, due to the high heterogeneity observed in overall HR and RR analysis, more studies could be necessary to confirm these results.     

Online patient education interventions in type 2 diabetes or cardiovascular disease: A systematic review of systematic reviews

Aims

Online patient education is a growing form of support to patients with chronic conditions, including type 2 diabetes (Type 2 DM) and cardiovascular disease (CVD). Multiple systematic reviews have been undertaken on this topic with conflicting results. We aim to explore the applications of online patient education in Type 2 DM and CVD and synthesise current evidence.

Whole grain intake and cardiovascular disease: a meta-analysis

Background and aimsWhole grain food sources have been associated with lowered risk of cardiovascular disease (CVD). Studies in recent years have strengthened this observation and elucidated potential mechanisms for this association. This study sought to quantitate the available observational evidence on whole grain intake and clinical cardiovascular events.Methods and resultsSeven prospective cohort studies with quantitative measures of dietary whole grains and clinical cardiovascular outcomes were identified from MEDLINE searches and a review of the literature. Based on event estimates adjusted for cardiovascular risk factors, greater whole grain intake (pooled average 2.5 servings/d vs. 0.2 servings/d) was associated with a 21% lower risk of CVD events [OR 0.79 (95% CI: 0.73–0.85)]. Similar estimates were noted for different CVD outcomes (heart disease, stroke, fatal CVD) and in sex-specific analyses. Conversely, refined grain intake was not associated with incident CVD events [1.07 (0.94–1.22)].ConclusionsThere is a consistent, inverse association between dietary whole grains and incident cardiovascular disease in epidemiological cohort studies. In light of this evidence, policy-makers, scientists, and clinicians should redouble efforts to incorporate clear messages on the beneficial effects of whole grains into public health and clinical practice endeavors.     

Recessive protective effect of ADIPOQ rs1501299 on cardiovascular diseases with type 2 diabetes: a meta-analysis

The association between a common variant of the ADIPOQ gene rs1501299 (+276G>T) and cardiovascular diseases (CVDs) outcomes has been reported with many studies. However, the evidence is insufficient for strong conclusions regarding CVDs and ADIPOQ rs15011299 (+276G>T). We performed a meta-analysis about the association between ADIPOQ rs1501299 (+276G>T) and CVDs risk using a predefined protocol, including 15 published studies with 5868 cases and 10,744 controls. The pooled data suggested a recessive protective effect of ADIPOQ rs1501299 (+276G>T) on CVDs for type 2 diabetes (T2D) population: the TT homozygote individuals had a reduced risk of developing CVDs compared to the carriers of G allele (OR = 0.74, 95% confidence interval (CI): 0.58, 0.94; p = 0.013). But there is still not enough evidence to indicate the association of the ADIPOQ rs1501299 (+276G>T) and the development of cardiovascular diseases (CVDs) outcomes in general population. In conclusion, our meta-analysis suggested that the ADIPOQ rs1501299 (+276G>T) polymorphism is a low-risk factor for the development of CVDs with T2D, but the association of this polymorphism with the susceptibility to CVDs in other populations remains unknown. It could be presumed that the ADIPOQ rs1501299 (+276G>T) be a potential cause of susceptibility to CVDs in persons with T2D, and it gives a new opportunity to investigate the mechanisms of CVDs susceptibility in T2D patients.     

The association between metabolic syndrome and polycystic ovary syndrome: A systematic review and meta-analysis

BackgroundOne of the most frequently encountered endocrinopathy in women of reproductive age is polycystic ovary syndrome (PCOS). Recent studies have reported varied prevalence of metabolic syndrome (MetS) in women with PCOS. The aim of this study is to determine if the women with PCOS are at a higher risk of MetS.MethodThe present systematic review and meta-analysis was conducted according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines. To collect articles, we searched online databases of PubMed/Medline, Scopus, Web of Science, Science Direct, Embase, CINAHL, Cochrane Library, EBSCO and Google scholar search engine and the reference list of the retrieved articles using MeSH keywords of “metabolic syndrome”, “woman” and “polycystic ovary syndrome” without time limit until October 2018. Cochran's Q test and I² Index were used to evaluate the heterogeneity among studies and the random effects model was used for combining the results. Data analysis was performed in STATA software version 11.1.ResultFinally, 72 studies involving 10075 PCOS patients with an average age of 26.2 ± 5.01 years were included in the meta-analysis. The heterogeneity rate was high (I² = 76.5%; p < 0.001) and the pooled estimate of the association between MetS and PCOS was significant (OR = 2.57, 95% CI: 2.18–3.02; P < 0.001).ConclusionAccording to the results, there is higher risk of MetS in women with PCOS. Therefore, diagnosis and treatment of MetS in women with PCOS may have a significant impact on this patients health and reduce the rate of mortality and morbidity.     

The prevalence of metabolic syndrome in postmenopausal women: A systematic review and meta-analysis in Iran

Metabolic syndrome is a set of cardiovascular risk factors that increase the risk of cardiovascular disease, diabetes and mortality. Women are at risk of developing metabolic syndrome as they enter the postmenopausal period. The present systematic review and meta-analysis was conducted to estimate the prevalence of metabolic syndrome in Iranian postmenopausal women. In this systematic review and meta-analysis, 16 national articles published in Persian and English were gathered without time limit. National databases such as SIDs, IranMedex and MagIran, and international databases such as Web of Science, Google Scholar, PubMed and Scopus were used to search the relevant studies. We searched for articles using the keywords “menopause”, “postmenopausal”, “metabolic syndrome”, “MetSyn”, and their combinations. Data were analyzed using the meta-analysis method and the random effects model. Analysis of 16 selected articles with a sample size of 5893 people showed that the prevalence of metabolic syndrome in Iranian postmenopausal women was 51.6% (95% CI: 43–60). The prevalence of metabolic syndrome based on ATP III and IDF criteria was 54% (95% CI: 59–63) and 50% (95% CI: 45–56), respectively. Based on the results of univariate meta-regression analysis, the increase in the mean age of postmenopausal women (p?=?0.001) and sample size (p?=?0.029), the prevalence of metabolic syndrome increased significantly. More than half of postmenopausal women in Iran suffer from metabolic syndrome. Providing training programs for postmenopausal women to prevent and control cardiovascular disease and its complications seems to be necessary.