A study of older adults in the United Kingdom finds that people who are lonely are more likely to develop type 2 diabetes, independent of other risk factors such as smoking, alcohol consumption, and weight.
Loneliness, in which a person’s social needs are not met, may be on the rise. A recent report found that almost half of people in the United States sometimes or always feel alone.
Loneliness is even more common among younger generations, with almost 80% of Gen Z and more than 70% of millennials experiencing this feeling.
Some believe that technology may play a part in feelings of loneliness among younger generations, with social media and other forms of online communication increasingly replacing genuine human connection.
Beyond the negative emotional impact of feeling isolated, loneliness is also a major risk to physical health. Research has associated loneliness with coronary heart disease and found that loneliness may be a greater threat to health than obesity.
One study even suggested that people who are lonely have a higher mortality risk than individuals who do not feel alone.
A new study from Kings College London in the U.K. adds to the list of health concerns associated with loneliness, finding that people who are lonely may be more likely to develop type 2 diabetes.
The researchers found that loneliness was a significant predictor of diabetes. This finding held when they took account of potential confounding factors, such as age, sex, ethnicity, wealth, smoking, physical activity, body weight, alcohol consumption, hypertension, and cardiovascular disease.
The findings appear in the journal Diabetologia.
The study, which is the first to find an association between loneliness and type 2 diabetes, is based on data from more than 4,000 people aged 50 years and above, with an average age of 65 years. The collection of the data took place during the English Longitudinal Study of Ageing.
At the start of the current study, none of the participants had diabetes, and they all had blood glucose levels within a healthy range.
During a follow-up period of 12 years, 264 people in the study (roughly 6% of the sample) developed type 2 diabetes.
The researchers found that the level of loneliness that people experienced at the start of the study was a significant predictor of who would go on to develop diabetes.
The assessment of loneliness occurred at the start of the study using a scale that a psychologist at the University of California, Los Angeles, developed. The scale requires people to rate questionnaire items such as “How often do you feel that you lack companionship?” and “How often do you feel part of a group of friends?”
The researchers found a significant association between loneliness and the onset of type 2 diabetes, even when they controlled for confounding factors, including smoking, alcohol consumption, weight, blood pressure, and cardiovascular disease.
The association was also independent of mental health factors, such as depression and whether a person lived alone.
“The study also demonstrates a clear distinction between loneliness and social isolation, in that isolation or living alone does not predict type 2 diabetes, whereas loneliness, which is defined by a person’s quality of relationships, does,” explains lead author Dr. Ruth Hackett.
This finding highlights the importance of the quality of human interactions that a person has, rather than the quantity.
Although the reason for this association is not yet clear, the researchers suggest that it could be related to how the body manages stress.
Previous research has shown, for example, that loneliness is associated with changes to levels of the stress hormone cortisol, which plays a role in diabetes.
“If the feeling of loneliness becomes chronic, then every day you’re stimulating the stress system, and over time, that leads to wear and tear on your body, and those negative changes in stress-related biology may be linked to type 2 diabetes development,” explains Dr. Hackett.
However, it is important to note that this is currently only a hypothesis. Although this study provides a correlation between loneliness and type 2 diabetes, it does not show a causative link between the two factors.
Other limitations of the study include the fact that there was only one measurement of loneliness during the study. Also, the data on type 2 diabetes were based on self-reporting, rather than objective medical records.
The authors also note that the overall strength of the association between the two factors was small. Nevertheless, the study highlights loneliness as a potential risk factor for type 2 diabetes and provides a basis for future studies to investigate this connection in more detail.