This week we learned something very important about diabetes. We learned that we don’t know something we thought we knew. (Regular readers will note that this keeps happening in medicine. For a generation everyone assumes something. Then we check and discover it isn’t so.)
We’ve always assumed that in type 2 diabetes, the closer to normal that blood sugar is lowered the fewer complications of diabetes patients would have. Why? Because diabetes is known to be a major cause of kidney disease, blindness, strokes and heart attacks, and we always assumed these complications are caused by the abnormally high blood sugars in diabetes.
We also have good studies in type 1 diabetes which prove that keeping sugar levels close to normal prevents complications. So we assumed that this also applied to type 2 diabetes, even though type 1 and type 2 are completely different diseases.
With me so far? We had lots of good reasons to assume that better sugar control in type 2 diabetes leads to fewer complications, and this assumption has guided diabetes management. Finally a trial was undertaken to test this belief. The Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial enrolled over 10,000 people with type 2 diabetes who either already had cardiovascular disease or were at high risk for it. The patients were randomized to one group which received conventional treatment which lowered sugars but not to normal levels, and another group which received intensive treatment which reduced blood sugars to non-diabetic levels.
This week the ACCORD trial was stopped early because of excess deaths in one group. What stunned experts and will confuse diabetes management for some time is that the group with excess deaths was the group receiving intensive treatment. This received a lot of media attention, including this NY Times article and this LA Times article.
So intensive lowering of sugars in type 2 diabetes is worse than more lax control of sugars, at least in patients with multiple risk factors for cardiovascular disease. The burning questions now are: What should our goal for blood sugars be? How low is too low? Do medicines that lower blood sugar in type 2 diabetes do any good? No one knows.
For now the experts are calming the public by urging them not to change any of their medicines before discussing it with their doctor, but this reassurance simply covers up the ignorance in which we find ourselves mired. The scary truth is that as of this week, and until more studies help us, we’re not really sure how we should be treating diabetes.
(I am grateful to Judy F. and Victoria W. for pointing me to the articles.)