Loneliness is a distressing emotion that occurs when there is a perceived imbalance between one’s social needs and the quality of one’s social relationships. While loneliness is not diagnosed as a mental health condition, it is complex and unique to each person. Previous studies suggest that depression and insomnia are risk factors for type 2 diabetes (T2DM), mediated via the body’s physiological stress response. Loneliness can lead to depression and can also contribute to sleep disorders, but the link between loneliness and risk for T2DM is poorly understood.

A study by Professor Henriksen and colleagues, published in Diabetologia, examined the impact of varying degrees of loneliness on risk for T2DM, and whether insomnia or depression mediated this association. The study included 24,024 individuals who participated in three surveys assessing self-reported loneliness (HUNT 2 [1995–1997], depression and insomnia (HUNT 3 [2006–2008]) and HbA1c (HUNT 4 [2017–2019]).