Metformin ? help or hindrance to type 2 diabetes patients? ability to exercise?

Exercise ? it?s a common prescription for conditions from diabetes to obesity, but if we?re taking medication as well, can that make it harder for us to get on the treadmill or go for a walk?Exercise

07 August 2007

Exercise ? it?s a common prescription for conditions from diabetes to obesity, but if we?re taking medication as well, can that make it harder for us to get on the treadmill or go for a walk?

Exercise physiologist, Dr. Normand Boul?, an expert in diabetes and physical activity says there?s good reason to ask. ?When people are diagnosed with type 2 diabetes, they?re typically told to watch their diet, and add exercise to their daily regimen - and, more often that not, they?re given a drug to help them keep glucose (sugar) levels in check.?

Often that drug is metformin. While it?s not a new drug ? it?s been on the market for 30 years in Canada and is one of the most commonly prescribed - we?re not really sure how it interacts with the human body ? and its ability to exercise.

Boul? started looking at that question last year, putting athletes who were not diabetic through a battery of tests which involved giving them a single dose of metformin then looking at their ability to exercise both on and off the drug.

Results were encouraging, he says. ?We originally thought that metformin might make it harder to exercise but results from the study with the athletes didn?t support that. The athletes used more oxygen (when taking metformin) and had lower lactate levels. This may be an indication that people are producing energy more aerobically as opposed to anaerobically (while taking metformin), which may suggest they will be able to sustain that type of exercise longer.?

Now he?s engaged in the next phase of this work ? a study funded by the Alberta Diabetes Institute, that involves recruiting subjects with type 2 diabetes, but who are not taking metformin.

?We need 12 participants for the study,? says Boul?. ?There are already five involved, but I do need another seven.? And he needs them soon, as he?d like to complete the study in December.

?In this study we?re looking at how metformin affects their (people with type 2 diabetes) ability to exercise. We?re also going to have the opportunity of seeing how exercise affects the rate at which metformin appears in the bloodstream and then disappears through the urine.? Thirdly the research team will look at the effects of exercise or metformin on how study subjects respond to a meal. ?We?ll be looking at how the body can control glucose levels,? says Boul?, noting that tests will include combining metformin and exercise, and also looking at the effects of each individually.

?It will be interesting to see how these two treatments can be used by people with diabetes to keep their blood sugar within healthy levels.?

Why is this study important? Says Boul?, ?There?s a great need in many fields to understand how the medications we use affect exercise or how exercise affects medication ? especially when exercise is the recommended treatment in that same population. Most medication studies are very standardised and very few look at these types of interactions.

This study may help us have a better understanding about the extent to which exercise can lower the dose of medication that?s needed, or what types of exercise are easier or harder for people with diabetes when they?re taking medication. It all fits into the bigger picture of gaining a better understanding of how we?re treating people.?

If you?d like to be part of the study, please contact graduate student Cheri Robert at 492-7394 or email exercise@ualberta.ca.

Criteria:

  • Men or women who have type 2 diabetes
  • Between the ages of 30 ? 65
  • Non-smoker
  • Not taking medication for their diabetes

Your commitment:

  • 3 months

What you?ll do:
  • You?ll be required to make six visits to the University of Alberta
  • First visit ? we provide you with detailed information and determine if you qualify for the study. (One hour)
  • Second visit ? collect fitness measures (two hours)
  • Visits three, four and five (six hours each) ? we look at how your blood sugar responds to different exercises and meals
  • You will be asked to take metformin or placebo tablets for 28 days each month during the study period
Side effects to metformin are considered minor. These include increased risk of headaches, nausea or diarrhoea.