The Cause of Type 2 Diabetes May Not Be What You Think
By Susannah Chen
A newly published study found that type 2 diabetes is not attributed to having obesity as defined by BMI. Rather, each individual’s genetics determine whether or not they have become too heavy for their body and have too much fat inside the pancreas and liver than they can tolerate.
The onset of type 2 diabetes is not attributed to having obesity as defined by body mass index (BMI), a new study has found. It’s actually caused by having more fat inside the liver and pancreas than that particular person can handle.
Dr. Roy Taylor, professor of medicine and metabolism at the University of Newcastle School of Medicine in England and lead investigator for the study, discussed the newly published results of the ReTUNE trial at the 59th European Association for the Study of Diabetes in Hamburg, Germany.
The ReTUNE Trial in Type 2 Patients Without Obesity
The trial recruited 20 participants who had been diagnosed with type 2 diabetes within the past 6 years, were not on insulin, and who had a body mass index in the “healthy weight” category. (Since other types of diabetes, such as type 1 autoimmune diabetes and monogenic diabetes, are more common in this weight group, participants were also screened to ensure that other forms of diabetes were excluded.)
Participants then underwent cycles of weight loss to achieve a rapid body weight reduction in 5% increments. This was achieved through two to four weeks of an 800-calorie-per-day Mediterranean-style diet. These rapid weight loss cycles were followed by four to six weeks of maintenance at a stable weight. If participants’ A1Cs remained above 6.5, then they were permitted to take up to two more cycles to achieve an additional 5% body weight reduction per cycle.
Metabolic assessments were made after each weight loss cycle as well as after 12 months to determine how closely metabolic features such as blood glucose and A1C returned to normal.
The study found that most people with recently diagnosed type 2 diabetes were able to return to normal blood sugar, liver fat, and fat export levels long term, and that 70% of participants were able to achieve diabetes remission (defined as an A1C below 6.5). The bottom line? Individuals have differing susceptibility to fat excess, Taylor said. “A person with type 2 diabetes has become too heavy for their own body, their own genetic constitution. “It is caused by more fat inside the liver and pancreas than can be tolerated by the individual.”
A Blood Test For "Personal Fat Thresholds"?
The ReTUNE trial also had a second aim: to test whether it is possible to detect that normal fat stores have been overfilled and people have exceeded their personal fat thresholds by a simple blood test, as well as whether it’s possible to see those fat stores return to normal when diabetes is put into remission. While initial data appeared promising – fat stores appeared to be elevated at the beginning of the study and decreased once A1C decreased – Taylor and his colleagues determined that more research using a larger study size is needed to determine whether this blood test has potential to be a reliable indicator.
Taylor was the lead investigator in an important trial called the DiRECT study that demonstrated that weight loss using a low-calorie diet can help put type 2 diabetes into remission in people who were recently diagnosed, and that people who have type 2 diabetes in remission can sustain it for up to five years if weight gain is avoided using a low-calorie diet.
