Abstract
This scoping review aimed to explore and synthesize existing research on predictors of loneliness, and the impact of loneliness on physiological and psychological health outcomes and health behaviors in older adults with diabetes. Results from 12 studies showed that low education, being unmarried/divorced/separated, having diabetes-related complications, being physically inactive, having diabetes distress, being of a certain race/ethnicity, being female, having depressive symptoms, and being younger age were consistently identified as predictors of loneliness. In addition, loneliness was found to affect both psychological (depressive symptoms and negative perceptions of diabetes) and physiological health outcomes (increased postprandial blood glucose and A1C levels, decreased cortisol levels, increased MCP-1 levels, slower gait speed, and weaker hand grip) and health behaviors (decreased engagement in physical activity, increased disability in activities of daily living and instrumental activities of daily living, and increased likelihood of antidepressant use). The results of this scoping review suggest that loneliness is a complex issue for older adults with diabetes and its effects are far-reaching. Therefore, further research should be conducted to explore the potential causal relationships between loneliness and physiological and psychological health outcomes and to identify the best interventions to reduce loneliness in older adults with diabetes. For healthcare providers, it is important to recognize that loneliness is an appropriate risk factor for older adults with diabetes that may affect psychological and physiological health outcomes and health behaviors and to address it through interventions such as social support programs, group therapy, or psychosocial counseling.