Joint association of loneliness and traditional risk factor control and incident cardiovascular disease in diabetes patients

Aims: To investigate the prospective associations of the loneliness and social isolation scales with cardiovascular disease (CVD) risk in diabetes patients and compare the relative importance of loneliness and social isolation with traditional risk factors. Also, the interactions of loneliness or isolation with the degree of risk factor control in relation to CVD risk were evaluated.

Methods and results: A total of 18 509 participants diagnosed with diabetes from the UK Biobank were included. A two-item scale and a three-item scale were used to assess loneliness and isolation levels, respectively. The degree of risk factor control was defined as numbers of glycated hemoglobin (HbA1c), blood pressure (BP), low-density lipoprotein cholesterol (LDL-C), smoking, and kidney condition controlled within the target range. During a mean follow-up of 10.7 years, 3247 total CVD incidents were documented, including 2771 coronary heart disease and 701 strokes. In the fully adjusted model, compared with participants with the lowest loneliness score (zero), hazard ratios (95% confidence interval) for CVD were 1.11 (1.02 and 1.20) and 1.26 (1.11 and 1.42) for participants with a loneliness scale of 1 and 2, respectively (P-trend < 0.001). No significant associations were observed for social isolation. Loneliness ranked higher in relative strength for predicting CVD than the lifestyle risk factors in diabetes patients. A significant additive interaction between loneliness and the degree of risk factor control on the risk of CVD was observed (P for additive interaction = 0.005).

Conclusion: Among diabetes patients, loneliness, but not social isolation scale, is associated with a higher risk of CVD and shows an additive interaction with the degree of risk factor control.