Loneliness has reached epidemic proportions. This year, former U.S. surgeon general Vivek Murthy wrote that “loneliness and weak social connections are associated with a reduction in lifespan similar to that caused by smoking 15 cigarettes a day and even greater than that associated with obesity.” Social isolation takes a toll on the body, with scientists previously spotting links to the development of hypertension, an increased risk of Alzheimer’s disease and a propensity in general toward premature death.
To add to this growing list, researchers at the Maastricht University Medical Center in the Netherlands found that people with larger social groups receive fewer type 2 diabetes diagnoses compared to socially isolated people. This research, published Monday in the journal BMC Public Health, suggests that promoting social interaction could prevent or treat type 2 diabetes.
“Most diabetes prevention efforts focus on becoming more physically active or modifying one’s diet, which are hard to achieve,” Miranda Schram, an epidemiologist at Maastricht University and study co-author, told PBS NewsHour. “So we wanted to look for effective, alternative strategies that can be used for intervention.”
To look for a connection between social interaction and diabetes, the research team needed to study a large-scale population. Luckily, the ongoing Maastricht Study–a comprehensive search for genetic and environmental risk factors involved in type 2 diabetes –shared 2,861 of its participants. The group, aged 40 to 75, hailed from the southern Netherlands.
Forty-three percent of the participants had either prediabetes, a recent diagnosis or existing type 2 diabetes. The rest of the group had normal glucose levels.
The team then collected information about each individual’s social networks using questionnaires and observed their social behaviors over a period of three months.
Women with normal glucose levels had, on average, 12 people in their social networks, while women with prediabetes or diabetes had fewer, about eight to 11 people. The researchers recorded similar statistically significant differences in the social networks of men with normal glucose levels and prediabetes versus men with type 2 diabetes. Women had larger social networks overall.
The team found that isolated women had a 112 percent higher chance of type 2 diabetes relative to women with larger social networks, while withdrawn men had 42 percent more likely to have the disease.
The case for close friends
Stephanie Brinkhues, a public health researcher at Maastricht University and lead author of the study, said their work showed emotional support, network size and different types of relationships can influence the risk of type 2 diabetes.
But why? Well, the team found some possible explanations among men who live alone and women with “close” relationships.
Men living alone had 94 percent higher odds of type 2 diabetes. Schram said some men noted poor dietary habits at home and lacked people to encourage them to stay healthy. “Medical professionals may need to start recognizing and focusing on single, socially isolated men as the most high-risk group,” Schram added.
In contrast, women showed a slight advantage over men because of a tendency toward larger social groups. The team found women who live near their friends and have tight-knit relationships fare much better. For example, if a woman in the study had 10 percent fewer friends living within walking distance, then she had significantly higher odds of diabetes, the researchers noted.
“As our numbers show, the size of the group and type of relationship makes a big difference for women, Brinkhues explained. “And keeping those friends close by is also a great benefit.”
But with family members, the trend switches. Men and women have higher odds of diabetes when more family live close. But specifically for women, having less family and more friends in their nearby networks presents them with more opportunities to get active and connect with a variety of people, Brinkhues added.
Though the researchers surveyed a relatively large population and the results revealed solid associations, science communicator and former researcher Gail Musen of the Cure Alzheimer’s Fund said this study could go a lot further.
“I hope to see the Maastricht group broaden this study to other nations and look at race, more age ranges, stress levels, sleep patterns, and the usual exercise and diet,” said Musen, who didn’t participate in this study but is an expert in diabetes and behavioral cognitive science.
Musen said health professionals should recommend cultivating broader, more genuine social groups to patients, but intervention and treatment need to happen on many levels. But as a first study of this kind, she added, these findings could open up a new dialogue and bring more attention to social isolation.