Casey Crump, MD, PhD
Physical fitness in late adolescence may reduce the risk of developing type 2 diabetes later in life, according to a new study from the Icahn School of Medicine at Mount Sinai that appeared online in the March 8, 2016, issue of the Annals of Internal Medicine.
Researchers—led by Casey Crump, MD, PhD, Vice Chair for Research in the Department of Family Medicine and Community Health at Icahn School of Medicine at Mount Sinai—evaluated data on the aerobic capacity of 1.5 million males who were military conscripts in Sweden between 1969 and 1997. The scientists then compared the men’s aerobic capacity to their medical diagnoses that were made between 1987 and 2012, when the men were a maximum age of 62.
The findings showed that low aerobic capacity correlated with an increased long-term risk for type 2 diabetes later in life, independent of the men’s body mass index (BMI), family history, or socioeconomic factors. A combination of low aerobic capacity and low muscle strength was associated with the highest risk, although aerobic capacity had a stronger influence.
“Most previous studies have examined physical fitness only in adulthood,” says Dr. Crump, who collaborated with researchers at Lund University in Sweden. “Few studies have examined physical fitness early in life, and none examined physical fitness in adolescence in relation to the long-term risk for type 2 diabetes. We also found that low muscle strength was an independent risk factor, although it was less influential than aerobic capacity.”
The study, funded by the National Institutes of Health and the Swedish Research Council, examined only males and did not measure physical fitness at older ages. But it, nonetheless, points to the important role that physical fitness plays in overall health and in adolescence.
Type 2 diabetes is a metabolic disease that causes sugar or glucose to collect in the bloodstream and can lead to heart disease, stroke, kidney disease, blindness, increased infections, and loss of toes, feet, or fingers as a result of poor circulation.
Over the past three decades, the prevalence of type 2 diabetes—the most common form of diabetes diagnosed primarily in adults—has more than doubled and now affects at least 300 million people worldwide. In the United States alone, 9.3 percent of the population has been diagnosed with diabetes and an estimated 8.1 million people have the disease but have not been diagnosed, according to the U.S. Centers for Disease Control and Prevention. The American Diabetes Association estimates the economic costs of type 2 diabetes and its complications exceed $200 billion annually in the United States.
While obesity is a well-established risk factor for type 2 diabetes, Dr. Crump says the study showed that physical fitness has important benefits even for people who are not overweight or obese.
In summary, says Dr. Crump, “Elucidation of these risk factors in young persons may help facilitate earlier and more effective preventive interventions.”