New Study Finds Loneliness A Risk Factor for Type 2 Diabetes

Loneliness may increase risk for type 2 diabetes, even in patients who are not socially isolated.  

Three well-known risk factors can increase a patient’s chances of type 2 diabetes: genetics, diet, and lifestyle.  New studies show that there may be another, social component that increases the chances of developing type 2 diabetes, as suggested by a study published in September 2020 in Diabetologia.  According to the authors of the study, feeling lonely, even when you are not living alone and have a social life with friends and family daily, is also associated with a higher risk for type 2 diabetes.   

The study’s researchers assessed loneliness by attaining a group of 4,000 participants who did not have type 2 diabetes, and questioning them on how often they were experiencing feelings of lack of companionship, being left out, or isolated from others.  The answers were averaged on a sliding scale of 1 to 3, with a higher score indicating they more frequently felt lonely, and a lower score meaning less often to not at all.  The researchers scheduled a decade of follow-up, in which 264 (6.4 percent) of participants developed type 2 diabetes. The specific group of participants who did develop diabetes previously scored their loneliness as an average of 1.42 compared to 1.33 for individuals who did not develop type 2 diabetes. The study also stated that patients with loneliness were at 46 percent greater odds of developing type 2 diabetes. The lead author, Ruth Hackett, Ph.D. of the Institute of Psychiatry, Psychology, and Neuroscience at King’s College London in the United Kingdom, suggested that the study showed a strong relationship between loneliness and the later onset of type 2 diabetes. She also stated that the most shocking aspect is that the relationship was robust even when they considered the critical factors to diabetes, such as smoking, alcohol intake, blood glucose, and mental health factors like depression. She concluded that there was an independent effect of the development of diabetes due to loneliness.   

A doctor of science and doctor of philosophy and the head of the department of behavioral science and health at University College London in the United Kingdom, Andrew Steptoe, stated that this is the first study to demonstrate that loneliness is linked to increased risk of developing type 2 diabetes.  Previous researchers showed that social isolation is related to type 2 diabetes, but Dr. Steptoe stated that isolation and loneliness are not the same. He described loneliness as a subjective experience of dissatisfaction with a person’s social and personal relationships, which may not necessarily be linked objectively with the number of close friends or social activities a person has.  Previous studies, like the BMC Public health study published in December 2017, suggested that a smaller number of friends and social interactions was associated with an increased risk of type 2 diabetes. The researchers of this study of loneliness and type 2 diabetes looked at how many close friends and family members were in regular contact with the patient and their daily lives, and found that a reduction by one person was associated with a 12 percent higher chance of developing type 2 diabetes for men and 10 percent in women. Isolation also was linked with a greater risk of premature deaths, according to the Heart study published in December 2019. The heart study was a one-year study that followed up with patients who were hospitalized for heart problems. Specifically, women in the study who reported high loneliness levels were three times more likely to die during the study, while men who reported loneliness during the study were twice as likely.   

The study did have some limitations, including that assessing loneliness was only done once at the beginning of the study. The study also failed to examine how the person experienced loneliness, and if it was through living alone, or social isolation. The study concluded that psychological stress that developed as a result of feeling lonely might lead to people having persistently elevated levels of the stress hormones epinephrine and cortisol, which both play an essential part in type 2 diabetes, according to Yacob Pinchevsky, Ph.D., of the faculty of health sciences at the University of the Witwatersrand in Johannesburg, South Africa.  Loneliness is a subjective emotion, so more friends and social contacts don’t necessarily mean people will feel less lonely.  Many people who push outside of their comfort zone to socialize more may also feel the stress of cortisol and inflammation contributing to type 2 diabetes.   

Practice Pearls:  

• Loneliness is a subjective feeling of dissatisfaction with social and personal relationships, while isolation is separation from family and friends.    
• Loneliness causes an increased amount of epinephrine and cortisol, which are critical factors in type 2 diabetes.   
• Loneliness is not necessarily a factor of not having people around, but of feeling lack of emotional support in relationships. 

Ruth A. Hackett, Joanna L. Hudson & Joseph Chilcot, Loneliness and type 2 diabetes incidence: Diabetologia  

Rapaport, Lisa, et al. Loneliness Linked to Higher Type 2 Diabetes Risk,  Sept. 2020.  

A’Kira Shavers, PharmD Candidate 2021, South College School of Pharmacy