Geographic distribution of metabolic syndrome and its components in the general adult population: A meta-analysis of global data from 28 million individuals.

AIMS: Better knowledge of the global metabolic syndrome (MetS) prevalence and its components is a prerequisite to curb the related burden. METHODS: We systematically searched PubMed, EMBASE, Web of Knowledge, Africa Journal Online, Global Index Medicus up to May 23, 2021. Prevalence pooling was done with a random-effects meta-analysis. RESULTS: In total, 1,129 prevalence data (28,193,768 participants) were included. The MetS global prevalence varied from 12.5% (95 %CI: 10.2-15.0) to 31.4% (29.8-33.0) according to the definition considered. The prevalence was significantly higher in Eastern Mediterranean Region and Americas and increased with country's level of income. The global prevalence was 45.1% (95 %CI: 42.1-48.2) for ethnic-specific central obesity, 42.6% (40.3-44.9) for systolic blood pressure (BP) ≥ 130 mmHg and/or diastolic BP ≥ 85 mmHg, 40.2% (37.8-42.5) for HDL-cholesterol < 1.03 for men or < 1.29 mmol/L for women, 28.9% (27.4-30.5) for serum triglycerides ≥ 1.7 mmol/L, and 24.5% (22.5-26.6) for fasting plasma glucose ≥ 5.6 mmol/L. CONCLUSIONS: This study reveals that MetS and its related cardiometabolic components are highly prevalent worldwide. This study calls for more aggressive and contextualized public health interventions to tackle these conditions.

Global, regional, and country estimates of metabolic syndrome burden in children and adolescents in 2020: a systematic review and modelling analysis.

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 (τ2) 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.