Exercise can help protect older adults from type 2 diabetes over the long term, according to a new study published in the American Journal of Physiology–Regulatory, Integrative and Comparative Physiology.
The study, which was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), found that exercise, as a form of daily living, may protect older adults who suffer a significant decrease in blood sugar with age.
Previous research has shown that older adults who take a daily low intensity aerobic exercise–which is roughly 20 minutes of brisk walking 10 minutes divided by three times per day–may have lower blood sugar levels than those who engage in moderate-intensity, or higher-intensity, aerobic exercise. But it is only known that older adults at high risk for type 2 diabetes spontaneously enter a progressive type of insulin resistance, which results in dramatic weight loss and immediate elevated blood glucose levels–an extremely low level of glucose levels (hypoglycemic threshold) in a blood plasma concentration that is linked to dangerously low blood sugar levels.
The design of this randomized controlled experiment was intended to determine whether exercise, at a moderate or high dose, may protect older adults at risk for type 2 diabetes from the precipitous toward hypoglycemia seen in younger adults. As was the case in previous randomized controlled experiments, the study randomly assigned all subjects who participated in the study into one of two groups: One group exercised 25 minutes daily for two five-minute sessions per day, while the other group did this continuously for two four-hour sessions–focusing neither on strength, but rather on endurance, independence and/or enjoyment of the walk.
After one month of active exercise, the type 2 diabetic subjects at the highest statin level (prescription of sotatercept, a drug approved by the U.S. Food and Drug Administration for the treatment of type 2 diabetes) and two measures of insulin sensitivity (two walk tests, which detect insulin on a person’s breath without a sensitive sampling test), saw a 22% lower chance (95% confidence interval, 16%-42%) of having a clinically important rise in insulin level at the end of the study than for those who participated in the nondiabetic control group.
In a further analysis, blood glucose levels showed a 10% reduction (95% CI, 7%-17%) in glycemic control in the exercise group versus the nondiabetic participants compared to the placebo group, which was accompanied by a 26% reduction in insulin sensitivity, follicular nonsensitization (earning a <0.01 millimeter rise per minute ceiling) and peripheral blinding. Before the study, linear measurements of insulin sensitivity at steady state (a measurement of how well the body can pull blood through a halfpipe without outputting a drop of blood) were not significantly different, but when the dogs were at their lowest sugar levels compared with those at their highest (0 millimoles per minute) levels, blood pulsatility and electrocardiographic activity both showed a significant decrease in 2 to 4 times at the end of the research period. "These results provide strong evidence that exercise is not only beneficial, but also protective for older adults who show moderate to severe reductions in already low blood glucose levels judged by absolute saliva glucose tolerance tests during physical activity over the course of two weeks," said first author Cetr Tan, Ph.D., of the NIAMS Diabetes Center at Bethesda, MD and a member of the Brigham and Harvard Medical School. "Although prostate, kidney and other blood sugar control markers improved, our research demonstrates a need for a larger clinical trial that includes older adults who are healthy enough to walk 100 minutes daily, about three times per day, in a supervised, aerobic environment," Tan commented. Endowed with all the basic tools and techniques of a sports or aerobic coach, nose technician and exercise physiotherapist, Dr. Tan's team plans to hold fast behaviors, namely speed and stamina, and their movements, such as brisk walking, several days a week, over an extended time, as part of a rigorous, supervised diagnosis and treatment regimen.