Abstract
In this review, we discuss how partnership and marriage influence cardiometabolic risk factors and risk of type 2 diabetes, and how couple-based approaches to type 2 diabetes prevention might complement individual-focused prevention efforts. There is some evidence that being married per se has a small positive effect on type 2 diabetes risk. Moreover, there is spousal concordance for many type 2 diabetes risk factors due to assortative mating and convergence during partnership, with weak to moderate correlations found for anthropometric measures, blood pressure, lipid concentrations, smoking, alcohol consumption and physical activity level. A meta-analysis shows that people have a higher risk of type 2 diabetes if their spouse has diabetes (OR 1.72, 95% CI 1.47, 2.02). However, despite some evidence, there is still a lack of research on similar associations in relation to progression to type 2 diabetes and diabetes complications. Several studies have suggested that behaviour changes, for example smoking cessation or weight loss, in one partner increase the likelihood that the other partner will make the same changes. Subsequent studies of couple-based interventions that focus on both partners have shown that people are more likely to adhere to a diabetes prevention programme if their partners are also involved in the programme. However, the effect of the quality of marriage on the outcome of an intervention is still unclear. Couple-based interventions are promising, but there is a lack of RCTs comparing couple-based interventions with individual-centred interventions.