Low level of physical fitness in early life associated with Type 2 Diabetes risk in adulthood

The combination of low aerobic capacity and low muscle strength at age 18 is associated with a three times greater risk of developing Type 2 Diabetes in adulthood, according to new research from the Icahn School of Medicine at Mount Sinai published online today in the journal Annals of Internal Medicine. The study also found that poor physical fitness was a long-term risk factor even among individuals with a normal Body Mass Index (BMI).

Researchers from Mount Sinai and Lund University in Sweden examined fitness and health records from more than 1.5 million male military conscripts in Sweden from 1969 to 1997. As a result of Sweden's national healthcare system, researchers were able to track the cohort's data over several decades (to a maximum age of 62 years) and obtain follow-up information to see if and when the conscripts were diagnosed with Type 2 Diabetes. Most studies of physical fitness have examined aerobic but not muscular fitness, and have focused on adults but lacked data at younger ages with sufficient follow-up to examine the long-term risk of Type 2 Diabetes.

"This is the first study to examine early-life physical fitness in relation to the long-term risk for Type 2 Diabetes in adulthood, independent of BMI, family history or socioeconomic factors" said Casey Crump, MD, PhD, Vice Chair for Research, Department of Family Medicine and Community Health and Senior Faculty, Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai and lead author of the study. "Our findings suggest that prevention should start early in life and should include both aerobic and muscular conditioning. We hope our research will help inform more effective lifestyle interventions among children and youth to promote better population health in the U.S. and other countries."

Diabetes, the seventh leading cause of death in the United States, is a metabolic disease that results in high blood sugar levels because the body does not produce enough insulin for proper function. Type 2 Diabetes is the most common form of diabetes and affects more than 300 million people worldwide. It has more than doubled in prevalence over the past 30 years, along with increasing rates of obesity and sedentary lifestyle.

"This research has enormous implications for the work we have been doing in our department, promoting adequate physical education programs in schools and the need for safe play spaces for children and teens in our communities," said Neil Calman, MD, Professor and Chair of Family Medicine and Community Health, Mount Sinai Health System. "Addressing these problems has now been proven to be of critical importance in preventing adult diabetes."

"Our research group is also studying the effects of aerobic fitness, muscular strength and BMI on other health outcomes, including ischemic heart disease and cancer," said Dr. Crump. "We need more longitudinal measurements of physical fitness over individuals' life course to determine age windows of greatest susceptibility to its effects on Type 2 Diabetes."