Different treatments for Type 2 diabetes

DEAR DR. ROACH: Recently, you said metformin lowers the insulin in your blood. Doesn’t it lower the blood sugar, not the insulin?

ANSWER: There are many different treatments for Type 2 diabetes (people with Type 1 diabetes are absolutely dependent on insulin).

Some treatments for Type 2 diabetes work by increasing insulin (obviously, insulin injections do), but there are oral medicines, such as glipizide, which work by making the pancreas secrete more insulin. Insulin lowers blood sugar by bringing sugar into cells. However, other types of medicines work through different pathways. Metformin works primarily by keeping the liver from making additional sugar.

This allows the insulin the body makes to work on dietary sugar alone, and thus decreases the need for insulin, and both blood sugar and blood insulin levels go down.

Type 2 diabetes is a disease of insulin resistance, and there are other classes of medicine that work on the resistance to insulin, such as pioglitazone (Actos). Insulin has growth-factor properties, so medicines that reduce insulin levels sometimes help with weight loss.

However, the choice of a particular medication for someone with Type 2 diabetes is complex, and there are many reasons other than insulin levels why a doctor chooses a particular drug for an individual.

That being said, usually metformin is the drug of first choice in people with Type 2 diabetes who are overweight, since there is good evidence that it is better than most other drugs in that common situation.

ToYourGoodHealth @med.cornell.edu.