The Relationships between Social Capital, Metabolic, and Behavioral Risk Factors of Non-Communicable Diseases: A Systematic Review

Background: Contextual risk factors such as social capital have a vital role in affecting behavioral and biological risk factors of NCDs. We aimed to systematically identify the relationship between different aspects of social capital (SC) with metabolic, and behavioral risk factors of non-communicable diseases (NCDs). Methods: This is a systematic review. The period of study was 2000-2021. We searched the English international databases, i.e. PubMed/Medline, Scopus, and Web of Science. Studies that reported NCDs' metabolic and behavioral risk factors as independent variables, were excluded. We also included studies if they analyzed the association between SC and metabolic and behavioral risk factors of NCDs.Results: After the primary and quality appraisal process, 97 studies were entered in the final phase of the analysis. Five out of 18 studies reported an inverse association between SC and the level of alcohol drinking. Twenty-seven out of 32 studies reported a significant inverse association between SC and smoking and tobacco use, while only one study reported a significant positive association. Nine studies reported a significant inverse association between SC and high blood pressure. Three studies showed a significant inverse association between SC and diabetes. Seventeen studies indicated a significant positive association between SC and physical activity. Thirteen out of 17 studies reported a significant inverse association between SC, body mass index (BMI) and overweight.Conclusion: High SC, people's participation and interaction are vital in tackling NCDs. Evidence shows positive effects of SC on prevention, control and improvement of NCDs' metabolic and behavioral risk factors.