Early Diagnosis of Diabetes Risk

Last summer, I blogged about a proposal to make the 1-hour instead of the 2-hour postprandial blood glucose (BG) level the standard measurement to diagnose impaired glucose tolerance. Now a second researcher has made a similar proposal.

The first author, Michael Bergman, kindly sent me the full text of the article, which has 12 authors from 6 countries: USA, Belgium, Denmark, Sweden, Portugal, and Israel. With such widespread support, it may be that other researchers and clinicians will begin to see the wisdom of this approach.

These researchers say that after a 75-gram oral glucose tolerance test, a 1-hour value of 155 or greater identifies people with reduced beta cell function, and such values are a stronger predictor of type 2 diabetes than the standard 2-hour result. They found this to be true in East Indian, Japanese, Israeli, and Nordic populations, suggesting, but not proving, that it's universal.

There's more and more evidence that complications such as neuropathy and vascular disease can occur at BG levels that aren't currently considered diabetic. And this article documents studies showing beta cell deterioration at similar levels.

So the earlier a patient realizes there's a problem, the earlier something can be done about it.

One problem is how much patients would cooperate with treating a condition that is mostly predictive. Increasing the risk of something doesn't guarantee that the event will occur, and patients tend to think it won't happen to them, like the smokers who keep smoking despite excellent evidence that smoking causes lung cancer.

Not too long ago, well, OK, about 20 years ago, but it seems like yesterday, the cutoff for diagnosing type 2 diabetes was a fasting level of 140 mg/dL, higher than the 126 mg/dL used today. But some physicians argued against diagnosing patients even at that level because they said once labeled as diabetic, the patients would face discrimination, especially from the insurance agencies. That's no longer permitted, at least in theory, but some discrimination probably still exists. Given a choice between a healthy applicant and a diabetic applicant with the same qualifications, one can guess which one would be hired.

The other problem would be how long patients diagnosed with pre-prediabetes would keep to healthier lifestyles or would want to take drugs like metformin that might help keep their BG levels down. Even patients with overt diabetes have difficulty sticking to their diets.

Despite these challenges, however, I think it would be useful for patients to know that they were at risk so at least some of them could take measures to stave off diabetes, or even prediabetes. There was recently a fascinating story about a genetics researcher, Michael Snyder, who, when his own DNA was sequenced, discovered he was headed for type 2 diabetes. With this proof, he subsequently altered his diet and exercise routine substantially and his numbers returned to normal.

Snyder is an example that shows that early diagnosis can result in preventing chronic diabetes. So even if the average patient wouldn't take pre-prediabetes seriously, some would, and that means it makes sense to change screening standards to the 1-hour measurement.