British scientists from the Institute of Psychiatry, King’s College London, found that loneliness was associated with the development of type 2 diabetes, independently of other known risk factors – including depression.
The study involved people over 50 years of age, permanently residing in the UK. Scientists assessed the degree of their loneliness using a three-point scale of the University of California at Los Angeles (USA). Participants answered the question “How often do you feel that you lack communication?” options of the answer “almost never / never” (1 point), “sometimes” (2 points) and “often” (3 points). From this, a conclusion was drawn about the degree of loneliness: the closer the score was to three, the more lonely a person was considered. They were also assessed for the presence of depression.
Of 4,112 people, 264 (6.42%) developed type 2 diabetes over the next ten years. Those who were diagnosed with diabetes were, on average, significantly more lonely (1.42 points) than those who did not develop diabetes (1.33 points). The risk of developing diabetes in lonely people was thus 42% higher. Initially, people who did develop diabetes reported significantly more pronounced depressive symptoms than those who did not.
Loneliness was found to be a significant risk factor for the development of diabetes mellitus during the observation period regardless of age, gender, ethnicity, financial status, smoking, physical activity, alcohol consumption, body mass index, glycosylated hemoglobin levels, arterial hypertension and cardiovascular diseases. The association between loneliness and type 2 diabetes in correcting depressive symptoms remained significant.
At the same time, social isolation did not have a significant effect on the development of type 2 diabetes. The results of the study show that loneliness can be considered a risk factor for developing type 2 diabetes over 12 years of follow-up, regardless of a number of adverse variables, including socio-demographic factors, attitudes towards one’s own health, and concomitant heart and metabolic diseases. This association persisted when corrected for depressive symptoms.