Any decrease in serum glucose pays for patients with pre-diabetes

Observational follow-up of participants in an earlier prevention of diabetes trial showed that those who had at least one normal serum glucose measurement during the trial had half the risk of developing diabetes over the 6-year follow-up compared with those who had high serum glucose in all measurements. Two and 3 normal blood glucose measurements conferred a 61% and 67% reduced risk of developing diabetes, respectively.

This finding was irrespective of group assignment in the three-arm trial, which lasted 3 years and tested an intensive lifestyle intervention, metformin, and placebo in the prevention of diabetes in people with high risk at baseline. Only those participants who did not develop diabetes during the trial (72% (1 990/2 761)) were included in the observational study. Serum glucose was measured twice a year.

Unexpectedly, among people without normal glucose measurements, those randomised to a lifestyle intervention had a 30% higher risk of developing diabetes than those who received placebo. It is not clear how to interpret this finding; it could be that people who responded poorly to a lifestyle intervention might have somehow been more susceptible to developing diabetes, or those who responded well to placebo might have been less susceptible.

In any case, the study seems to support early and aggressive lowering of blood glucose in people at high risk of diabetes. The linked comment suggests that future research should explore whether a similar strategy might reduce the risk of complications, such as blindness or vascular disease, in full-blown diabetes.

Diabetes Prevention Program Research Group. Lancet 2012;379(9833):2243-2251; doi:10.1016/S0140-6736(12)60525-X.