**Metformin controls the insulin resistance of people who have type 2 diabetes so well that, if possible, all of us should be taking it. That’s what Roderic Crist, M.D., told me at the annual convention of the American Society of Bariatric Physicians in Denver this weekend. Dr. Crist specializes in family medicine in Cape Girardeau, Missouri.
"Not everybody can take every drug," he added, when I followed up our conversation by calling him at his office after he returned home. "But most of the time people can take metformin if they take it carefully."
Roughly one-third of Dr. Crist’s patients have diabetes. Well over half, if not two-thirds of the people he sees are insulin resistant.
"I treat insulin resistance with that drug even if they aren’t fully diabetic." he says. "If they have high triglyceride levels and low HDL levels, particularly if they are centrally obese, they should probably be on metformin. It helps slow the progression of the disease from one thing to the next."
But he goes further. He prescribes metformin to almost all of his patients who have type 2 diabetes – no matter how low their A1C level is. And he tells his patients that their levels should be 5.0 or less – not the American Diabetes Association’s less stringent recommendation of 7.0 or less. "If their A1C is at 5, their diabetes is in complete remission. So I have that as a goal."
And he still prescribes metformin to them after they reach that goal. "The two important issues are that it will prevent progression and it should be used in the earliest phases of insulin resistance. We vastly underutilize metformin."
But he has a concern about the usual starting dose of metformin. "When most physicians prescribe metformin, they start way too high," he told me. "Almost all medications have side effects. For metformin the typical recommended dose is 500mg twice a day. They teach almost all of us physicians to do that and to increase it fairly rapidly to 850mg and then to 1,000mg twice a day. And almost all people who do that have GI side effects, typically nausea and diarrhea."
He recommends that we go much, much slower. "Start with 250mg perhaps for a week," he says. "And the second week to 250mg twice a day, and the third week to 500mg in the morning and 250mg at night, and the fourth week 500mg twice a day. And keep increasing at that rate very slowly, with the ultimate goal of 850mg twice a day or 1,000mg twice a day, depending on your needs. In this fashion you will rarely have side effects."
Furthermore, when you go off metformin for one reason or another and then go back on it, you need to follow the same slow course. "You have to start this whole process all over again – even if you go off metformin for just a few days," he says. "Taken correctly, it is far more well-tolerated."
He also prescribes other medications to essentially all of his patients who have diabetes. He says that he follows the recommendations for doctors to prescribe either ACE inhibitors (angiotensin-converting-enyyme inhibitors) or ARBs (angiotensin II receptor blockers) to everyone who has diabetes to protect their kidneys, unless they have low blood pressure.
Is there a third drug that everyone with diabetes should take? I asked Dr. Crist.
"That’s a tough one," he replied. "Perhaps aspirin, if there are no contraindications. Generally 81mg, but if you want to cover the entire spectrum of clotting disorders, perhaps two baby aspirin. I usually have most of my patients on aspirin, unless there is a contraindication."
I am still considering whether to follow Dr. Crist’s advice to go back on metformin. I did decide to again take a baby aspirin every day. All of his recommendations are certainly provocative and well worth our careful attention.
Metformin helps people with type 2 diabetes to control the amount of glucose in our blood. It decreases the amount of glucose we absorb from our food and the amount of glucose made by our liver. Metformin also increases our body’s response to insulin, a natural substance that controls the amount of glucose in the blood.
Metformin is one of the most effective of our diabetes medications, one of the safest, and now that generic forms are available is the least expensive. For several excellent reasons it is the most widely prescribed diabetes drug in the world.**
David Mendosa was a journalist who learned in 1994 that he had type 2 diabetes, which he wrote about exclusively. He died in May 2017 after a short illness unrelated to diabetes. He wrote thousands of diabetes articles, two books about it, created one of the first diabetes websites, and published a monthly newsletter, “Diabetes Update.” His very low-carbohydrate diet, A1C level of 5.3, and BMI of 19.8 kept his diabetes in remission without any drugs until his death.