Relationship between social isolation and glycaemic control of people previously diagnosed with diabetes: secondary analysis from the CHARLS

Objectives Social isolation may affect diabetes self-management. This study aimed to explore the relations between social isolation and glycaemic control in patients with diabetes and to explore lifestyle differences among individuals with different levels of social isolation. Methods The relevant data of 665 people previously diagnosed with diabetes included in the China Health and Retirement Longitudinal Study from 2011 to 2015 were extracted and analysed. The study included patient general information, blood glucose, lipids, glycosylated haemoglobin, social isolation index, health-related lifestyle factors and diabetes-related factors. Differences in metabolic abnormalities and modifiable lifestyles were compared among patients with varying levels of social isolation. Results Multiple linear regression analysis demonstrated that among men aged 45–64 years, the high social isolation group had significantly higher glycosylated haemoglobin levels compared with the low isolation group (7.29±1.81 vs 6.59±1.63, p=0.026). A positive correlation was observed between social isolation and blood glucose (β=14.16; 95% CI 2.75 to 25.57; p=0.015) and glycosylated haemoglobin (β=0.35; 95% CI 0.10 to 0.60; p=0.006), indicating that higher social isolation was associated with higher fasting blood glucose and glycosylated haemoglobin levels. However, no significant associations were observed in other age groups. Notably, men aged 45–65 years with high social isolation had higher depression rates (44.10% vs 24.60%, p=0.024), lower engagement in moderate exercise (5.70% vs 23.50%, p=0.019) and shorter 10-minute walks (17.10% vs 36.80%, p=0.027). Differences in other health-related and diabetes-related factors were not statistically significant. Conclusion Middle-aged men with diabetes with higher social isolation tend to have higher blood glucose and glycosylated haemoglobin levels. This subset of patients requires targeted attention to provide social support from family and friends for improved glycaemic control. If necessary, education on diabetes should be made available to family members and friends.