Exercise and prediabetes

November 9th, 2011 by Ryan Luce No Comments

written by Michael O’Leary

Dr. Barry Braun

If your doctor has told you that you are prediabetic, exercise training may be your best bet for preventing type 2 diabetes.

Researchers at the Energy Metabolism Laboratory of the University of Massachusetts, Amherst found that men and women with prediabetes who exercised and took a placebo increased their insulin sensitivity by 25 percent to 30 percent more than those who only took metformin and those who took metformin AND exercised.

While the researchers say the difference between exercise-only group and the metformin groups was too small to rule out the possibility that it was simply due to chance, it does show a trend favoring exercise over other actions you might take to prevent developing diabetes. The study was published online Oct. 31, 2011 in Diabetes Care. (Link to published site)

In the study, led by senior study author Dr. Barry Braun, 24 men and women with prediabetes were randomly assigned to one of three interventions for 12 weeks. One group of 8 engaged in an exercise-training program and took a placebo. The second group took metformin alone and the third group took metformin and participated in the same exercise-training program.

Before they started the study, their insulin sensitivity was measured using a special test called a hyperinsulinemic clamp that raises the insulin concentration in the blood and is considered the gold standard for measuring insulin sensitivity­ – an indicator of prediabetes. They repeated the test after the study was completed and compared the results.

They found that all three treatments had considerably higher insulin sensitivity relative to a group that neither exercised nor took metformin. The researchers suggested that adding metformin might actually blunt the full effect of exercise on insulin sensitivity.

Why that might be the case is unclear, but it supports the results of a Canadian study reported on by Corengi last August that showed metformin reduced blood glucose less effectively on days when participants exercised. The researchers in that study suggested that because both metformin and exercise act to lower glucose levels, the combination may trigger a counter regulatory response by the body to prevent glucose levels dipping too much.

In any case both studies are too small to draw any conclusions about taking metformin and exercising, but both studies confirm the value of exercise for preventing type 2 diabetes.