Sheba researchers collected health data on nearly 1.5 million 17-year-olds (58% male, 42% female) who were given medical evaluations before they began Israeli military service in 1996, and then followed their health histories through 2016. At the beginning of the study, none of the subjects showed any abnormalities in blood sugar levels, but over the succeeding years, 777 cases of type 1 diabetes were observed.
Over a median follow-up of about 11 years, researchers broke down the incidence of type 1 diabetes by different BMIs among the subjects (BMI, or body-mass index, is a standard by which overweight and obesity are measured). They found that the higher the BMI among a cohort of subjects, the more likely they were to develop type 1 diabetes. The idea that little or no relationship exists between type 1 diabetes and obesity was indeed called into question.
This raises the question – why? A separate article offered several hypotheses based on the researchers’ conjectures. The first, two body chemicals – adipokines and cytokines – which are known to be associated with obesity, also appear to be linked to inflammation, and inflammation is a contributing factor in diabetes. Another possibility is based on evidence that suggests obese individuals have a higher risk of islet autoantibody expression, a condition that appears to be linked to type 1 diabetes. Other factors include vitamin D deficiency, which is linked to obesity, a high fat diet, and the composition of the gastrointestinal microbiome, also known as gut microbiota.
Finally, there is the “accelerator hypothesis,” which suggests that both type 1 and type 2 diabetes are, in fact, the same disorder, which is fostered by beta cell death (death of the cells that produce insulin), beta cell autoimmunity, and insulin resistance. As insulin resistance is caused by weight gain, abdominal fat, and an inactive lifestyle, it’s possible that obesity might actually be a contributing factor to type 1 diabetes. In other words, lifestyle does indeed seem to play a significant role according to the study. As Dr. Gilad Twig, one of the study’s authors, puts it, “For people who might have a high risk for developing type 1 diabetes, these results emphasize the importance of maintaining a healthy weight.”