Prediabetes

Science magazine has a story suggesting that we retire the term prediabetes. They cite people who say the progression from prediabetes to diabetes is low (less than 2% per year or 10% in five years, rather than the 15% t0 30% that has been cited by the Centers for Disease Control and Prevention) and there are no drugs that specifically target prediabetes. So why worry people?

The Diabetes Prevention Program study, which ended in 2001, showed that those who received intensive lifestyle changes reduced their development of type 2 diabetes by 58 percent. But those patients received intensive counseling and support, which is too expensive to offer to every person diagnosed with prediabetes.

Metformin alone (850 mg twice a day) lowered diabetes incidence by 31 percent, but there was some disagreement over whether the drug really kept the patients from developing diabetes or whether the metformin simply masked any diabetes that developed.

These opponents of the idea of prediabetes also claim that prediabetes doesn't increase the risk of heart disease and argue that the costs of treating patients with prediabetes outweigh the benefits.

I understand their reservations, but I don't agree that we shouldn't warn people that they are on the track to diabetes. Patients are different, and there are always some who, when told they have prediabetes, will ask for a pill and not want to do anything about changing their habits. There are others who might like to eat a whole-food diet with lots of vegetables, but they can't afford it, or the stores in their area don't carry healthy foods.

But there are also patients who, if warned, will take serious steps to improve their health. A fascinating example of this is geneticist Michael Snyder, who found out as a result of an exhaustive genome and metabolic analysis that his blood glucose (BG) went very high after a viral infection, and when a doctor later said he had type 2 diabetes, he worked hard on diet and exercise and brought things back to normal.

Snyder recently published a paper on glucose spikes in nondiabetics. He says 70% of people with prediabetes will progress to overt diabetes.

So should motivated patients be denied early warnings just because other people won't do anything about their health?

And even if only 2% of patients per year progress to overt diabetes, if you're one of the 2%, wouldn't you want to be warned?

I also don't agree that prediabetes doesn't increase the risk of heart disease. I've seen studies saying that even A1c's considered normal increase the risk, but I didn't save them as I thought that was generally accepted. Here is one example.

One problem is that definitions of things like prediabetes and diabetes depend on where some group of physicians decide to put a cutoff point. It's not as if you're totally healthy until you reach that point and then suddenly you're sick. When I was diagnosed in 1996, the cutoff for diabetes was a fasting BG level of 140 mg/dL. Then that was reduced to 126. And fasting BG levels can change from day to day. Does that mean you can have diabetes on Wednesday when your fasting BG level was 127 but you were cured on Friday when it was 125?

Today the A1c is often used for diagnosis, but that too is not an exact method. When I've had A1c tests at two different sites, they often don't agree.

 So should we retire the term prediabetes?

When I was diagnosed, the term prediabetes didn't exist. Instead you were said to have impaired glucose tolerance if your BG levels went higher than normal after meals and impaired fasting glucose if they were high when you got up. Both categories were combined into the prediabetes term. I think it's less important what you call it than having a physician who will warn you if all is not well and then help you prevent diabetes, or who will refer you to someone else who can do this.

I think the term prediabetes probably has a bigger impact on the patient than something like impaired glucose tolerance so the patient will be motivated to do something about it. Most people who are diagnosed with diabetes are overweight, and most people who are overweight have been trying to lose weight off and on for years. A diagnosis of prediabetes can be the kick in the pants they need to take the weight loss seriously.

Regardless of whether or not you agree about dumping the term prediabetes, the article in Science is a good summary of how professional organizations can disagree about diagnostic criteria, how those who specify those criteria often receive large amounts of money from drug companies, and how attitudes change through the years.