Temporal Trends, Prevalence, and Determinants of Metabolic Syndrome in Sub-Saharan Africa: A Systematic Review, Meta-analysis, and Meta-regression.

Background Metabolic syndrome (MetS) is a cluster of interrelated metabolic abnormalities characterized by central obesity, elevated blood pressure, impaired glucose metabolism, hypertriglyceridemia, and reduced high-density lipoprotein cholesterol (HDL-C). These conditions frequently coexist because of common underlying mechanisms, including insulin resistance, visceral adiposity, chronic low-grade inflammation, and genetic susceptibility. Individuals with MetS are at substantially increased risk of developing type 2 diabetes mellitus, cardiovascular disease, chronic kidney disease, and premature mortality. As a result, MetS has become one of the leading contributors to the global burden of non-communicable diseases (NCDs). Over the past two decades, the prevalence of MetS has increased worldwide due to rapid urbanization, population ageing, sedentary lifestyles, unhealthy dietary habits, and increasing levels of overweight and obesity. This increase is particularly concerning in low- and middle-income countries, where health systems are simultaneously challenged by infectious diseases and the growing burden of NCDs. The coexistence of communicable and non-communicable diseases has created a double burden that threatens health system capacity and sustainable development. Sub-Saharan Africa (SSA) is undergoing rapid demographic, nutritional, and epidemiological transitions. Economic growth, urban expansion, changes in dietary patterns, reduced physical activity, increased life expectancy, and lifestyle modifications have contributed to rising rates of obesity, hypertension, dyslipidemia, and diabetes, which are the principal components of MetS. These changes have resulted in a growing burden of cardiometabolic diseases across the region. Furthermore, the high prevalence of HIV infection and increasing use of long-term antiretroviral therapy in several SSA countries add complexity to the epidemiology of metabolic disorders, making MetS an important emerging public health challenge. The prevalence of MetS reported across SSA varies considerably, reflecting differences in geographic location, study populations, diagnostic criteria, socioeconomic conditions, and study design. Studies have reported prevalence estimates ranging from less than 10% in some rural populations to more than 50% among urban residents and high-risk clinical populations. Such wide variation highlights the need for comprehensive evidence synthesis to obtain reliable regional estimates and identify factors contributing to heterogeneity. Several demographic, behavioral, and clinical characteristics have been associated with MetS. Increasing age, female sex, obesity, physical inactivity, unhealthy dietary practices, smoking, alcohol consumption, urban residence, and socioeconomic status have consistently been identified as important determinants. In addition, comorbid conditions such as type 2 diabetes, hypertension, and HIV infection may further increase the likelihood of developing MetS. Understanding these determinants is essential for designing targeted prevention and intervention strategies. Accurate estimates of MetS prevalence and a comprehensive understanding of its determinants are essential for guiding national NCD policies, allocating healthcare resources, identifying high-risk populations, and monitoring progress toward global health targets. Given the rapid epidemiological transition occurring across SSA, updated evidence is needed to support effective public health planning and strengthen prevention strategies aimed at reducing the burden of cardiometabolic diseases. Rationale of the Study Although several systematic reviews and meta-analyses have examined the prevalence of metabolic syndrome in Africa or Sub-Saharan Africa, important evidence gaps remain. Most previous reviews focused primarily on estimating pooled prevalence and were based on studies published before the most recent expansion of research in the region. Consequently, they may not adequately reflect the current burden of MetS in SSA. In addition, previous reviews have largely focused on pooled prevalence estimates, with limited assessment of how MetS prevalence has changed over time. During the last two decades, Sub-Saharan Africa has experienced substantial demographic, socioeconomic, nutritional, and lifestyle changes that are likely to have influenced the epidemiology of MetS. However, the temporal pattern of MetS prevalence across the region has not been comprehensively quantified using meta-regression techniques that allow the evaluation of changes over time while accounting for study-level characteristics. Furthermore, although numerous primary studies have investigated factors associated with MetS, no recent systematic review has comprehensively synthesized these determinants while simultaneously examining temporal trends in prevalence. Variations in diagnostic criteria, geographic region, study setting, participant characteristics, and methodological quality may explain much of the observed heterogeneity among published studies, yet these factors have not been fully explored using advanced meta-regression methods. This study addresses these gaps by systematically synthesizing evidence published between January 2006 and January 2026. It will estimate the pooled prevalence of MetS, evaluate temporal trends over two decades using meta-regression, identify determinants associated with MetS, and investigate sources of between-study heterogeneity. The findings will provide updated evidence on the changing burden of MetS in Sub-Saharan Africa and support policymakers, clinicians, and public health practitioners in designing evidence-based interventions and strengthening strategies for the prevention and control of non-communicable diseases across the region.