Q: I was just diagnosed with Type 2 diabetes. I don’t have any symptoms. My doctor discovered that my blood sugar was high when I had some routine blood tests performed. She wants me to start a medication called metformin. I would rather wait and try diet and exercise first. What do you suggest?
A: Exercise and weight loss are the ideal ways to deal with Type 2 diabetes. Just shedding 10 pounds and becoming more physically active will bring your blood sugars down.
The problem is that while many people can remain diet- and-exercise virtuous long enough to lose a few pounds — even 10 or so — most of us can’t stay that way. The lost weight has a way of finding its way back.
The American Diabetes Association’s guidelines acknowledge that people have trouble keeping weight off. “Lifestyle interventions” to lose weight and get more active are step one in its guidelines. But the association also says that new patients should start taking metformin (Glucophage) right away because most people don’t stick with diet and exercise year after year.
Metformin lowers blood sugar levels by decreasing the liver’s production of sugar and by increasing the effectiveness of insulin, the hormone that escorts sugar into cells. Insulin resistance is one of the main features of Type 2 diabetes. Cells start rebuffing the hormone, so sugar has nowhere to go. Levels in the blood start to climb.
Metformin is the first-line medication for several reasons. It’s effective, lowering blood sugar levels by about 20 percent. People don’t gain weight when they take it, in contrast to most of the other drugs used to treat Type 2 diabetes.
The most common side effects of metformin are gastrointestinal (a metallic taste in the mouth, nausea, diarrhea) and usually mild. In about a third of patients, the drug interferes with the absorption of vitamin B12, but not so much that it causes anemia.
There’s some controversy about whether we are turning to medications like metformin too soon. Proponents say they’re being realistic about lifestyle changes. Critics counter that not nearly enough has been invested in devising ways to make diet and exercise programs work.
In the not so distant past, I would have agreed with you — try diet and exercise for six months. But not now. Unless a person has altered kidney function, heart failure or significant liver disease, I advise starting the metformin right away along with lifelong changes in diet and exercise routines.
Dr. Howard LeWine is a clinical instructor of medicine at Harvard Medical School and practicing internist with Harvard Vanguard Medical Associates and Brigham and Women’s Hospital in Boston.
