BMI Found to Be a More Powerful Risk Factor for Type 2 Diabetes Than Genetics

Weight loss may be able to prevent or reverse type 2 diabetes (T2D), according to research presented at the European Society of Cardiology Congress 2020.

Ninety percent of approximately 463 million people worldwide with diabetes have T2D. Obesity is known to be the main modifier of T2D, but genes have also been found to be an indicator of a predisposition for T2D.

"Because we are born with our genes, it might be possible to pinpoint early in life who has a high chance of developing diabetes during their lifetime," said principal investigator Brian Ference, MD, MPhil, MSc, FACC, FESC, a professor at the University of Cambridge and visiting professor at University of Milan, in a press release. "We conducted this study to find out if combining inherited risk with current body mass index (BMI) could identify people at the highest risk of developing diabetes. Prevention efforts could then concentrate on these individuals."

In the study, the researchers assessed data from 445,765 participants of the UK Biobank. The participants had an average age of 57.2 years and 54% were women.

Using 6.9 million genes, the researchers analyzed the genetic data to assess the inherited risk for each participant. Additionally, they used the height and weight of participants to calculate their BMI in kg/m2. Participants were then categorized into 5 groups according to genetic risk for T2D and 5 groups according to BMI.

The researchers conducted a follow-up visit with the participants when they had an average age of 65.2 years. By that time, 31,298 of the participants had T2D.

Those in the highest BMI group with an average BMI of 34.5 kg/m2 were found to have an 11-fold greater risk of T2D than those in the lowest BMI group. Those in the group with an elevated BMI were found to have the highest likelihood of developing T2D during the study period, regardless of their genetic predisposition to the disease.

"The findings indicate that BMI is a much more powerful risk factor for diabetes that genetic predisposition," Ference said in a press release.

The researchers also investigated whether the duration of the period in which a participant has a high BMI played a role in T2D development. After using statistical methods to assess likelihood, they found the duration of an elevated BMI did not affect the risk of T2D.

"This suggests that when people cross a certain BMI threshold, their chances of diabetes go up and stay at that same high-risk level regardless of how long they are overweight," Ference said.

Additionally, Ference noted that the effect of an elevated BMI would most likely vary from person to person, with the key indicator being the point at which the individual starts to develop abnormal blood sugar levels.

"The findings indicate that most cases of diabetes could be avoided by keeping BMI below the cut-off which triggers abnormal blood sugar. This means that to prevent diabetes, both BMI and blood sugar should be assessed regularly. Efforts to lose weight are critical when a person starts to develop blood sugar problems," Ference said in the press release. "It may also be possible to reverse diabetes by losing weight in the early stages before permanent damage occurs."

REFERENCE

Body mass index is a more powerful risk factor for diabetes than genetics. European Society of Cardiology Congress 2020; August 31, 2020. sciencedaily.com/releases/2020/08/200831090129.htm. Accessed September 3, 2020.