Reduce obesity to prevent half of new Type 2 diabetes cases in U.S.

Up to half of new Type 2 diabetes cases in the United States could be prevented by reducing the prevalence of obesity, reports a new Northwestern Medicine study. 

Prevention is even more urgent because the obesity epidemic has collided with the COVID-19 pandemic, study authors said. Individuals with obesity have more severe COVID-19 infections and could experience more adverse health consequences in the coming years as a result.

“This is the first study to calculate trends in the percentage of new cases of diabetes due to obesity over time,” said senior author Dr. Sadiya Khan, assistant professor of medicine at Northwestern University Feinberg School of Medicine and a Northwestern Medicine cardiologist. “Obesity is a major contributor to diabetes. We’ve recently shown the years of life lost to diabetes is increasing.”

The study examined each race-sex group separately to show current and future trends of diabetes if obesity epidemic continues unchecked.

Findings

• Between one-third to one-half of new cases of diabetes are due to obesity in the United States
• This explains a large part of the increase in diabetes in the last two decades, and
• Significant differences exist in race-sex groups with greatest burden related to obesity among non-Hispanic women

The study was published in the Journal of the American Heart Association.

“Our study highlights the meaningful impact that reducing obesity could have on Type 2 diabetes prevention in the United States,” said study first author Dr. Natalie Cameron, a resident physician of internal medicine at the McGaw Medical Center of Northwestern University. “Decreasing obesity needs to be a priority. Public health efforts that support healthy lifestyles, such as increasing access to nutritious foods, promoting physical activity and developing community programs to prevent obesity, could substantially reduce new cases of Type 2 diabetes.” 

Type 2 diabetes is the most common form of diabetes, affecting more than 31 million Americans, according to the U.S. Centers for Disease Control and Prevention.

The number of deaths due to Type 2 diabetes, in people younger than 65, is increasing along with serious complications of the condition, including amputations and hospitalizations. Adults with Type 2 diabetes are twice as likely to have a heart attack or stroke than people without diabetes.

Researchers used information from the Multi-Ethnic Study of Atherosclerosis (MESA) and four pooled cycles (2001-2016) of the National Health and Nutrition Examination Survey (NHANES). MESA is an ongoing, longitudinal study of 45 to 84-year-olds who did not have cardiovascular disease upon recruitment. MESA data included in this study was collected during five visits from 2000 to 2017 at six centers across the U.S. NHANES is a cross-sectional study of the American population that takes place every other year using patient questionnaires and examination data. 

For this analysis, authors limited data to participants ages 45 to 79-years old. They included only those who were non-Hispanic white, non-Hispanic Black or Mexican American and who did not have either Type 1 or Type 2 diabetes at the beginning of the study. Researchers calculated both the prevalence of obesity and the excess risk of Type 2 diabetes associated with obesity.

“Our study confirms there is a higher prevalence of obesity among non-Hispanic Black adults and Mexican-American adults compared to non-Hispanic white adults,” Cameron said. “We suspect these differences may point to important social determinants of health that contribute to new cases of Type 2 diabetes in addition to obesity.” 

Co-authors are Lucia Petito, Megan McCabe, Norrina Allen, Dr. Matthew O’Brien and Mercedes Carnethon.

This research was supported by grant KL2TR001424 from the National Heart, Lung, and Blood Institute and the National Center for Advancing Translation Sciences at the National Institutes of Health and the American Heart Association.