Loneliness isn’t just an emotional struggle—it can also seriously impact physical health, including increasing the risk of type 2 diabetes.

A landmark Norwegian study spanning 20 years found that individuals who reported feelings of loneliness had more than double the risk of developing type 2 diabetes compared to those who didn’t—an adjusted odds ratio (OR) of 2.19 . Importantly, this risk wasn’t fully explained by related issues like insomnia or depression.

Further research across diverse populations supports this link. A Danish cohort of over 465,000 adults showed that “feeling lonely often” increased diabetes risk by 24% (HR 1.24), independent of factors like BMI and mental illness. A similar Chinese study revealed a 26% higher hazard of transitioning from prediabetes to diabetes among those experiencing frequent loneliness.

Biologically, loneliness triggers chronic stress responses—elevating cortisol and inflammatory cytokines—which in turn promote insulin resistance and glucose dysregulation. Weakened sleep, poor diet, and reduced exercise linked to social isolation further amplify this risk.

These findings suggest loneliness is a modifiable risk factor and point toward including social-connectedness strategies—like community engagement, therapy, or support groups—in diabetes prevention and public health guidelines.