Wednesday, October 17, 2007

Hemoglobin A1C Predicts Diabetes

Boy, does it predict diabetes.

A study appearing in the August issue of the American Journal of Medicine found that women, aged 45 or older, whose HbA1c was >7.0%, and who did not have diabetes, had an 81 times greater risk of being diagnosed with type 2 diabetes in the following 10 years, than women whose HbA1c was 5.0% or less.1

Participants were 26,563 women who took part in the Women's Health Study (WHS). They were followed for median of 10.1 years.


The risk for diabetes increased as HbA1c levels increased:

For women whose HbA1c was:
  • <5.0%, there was no greater risk.
  • 5.0% to 5.4%, the risk was 2.9 times greater.
  • 5.5% to 5.9%, the risk was 12.1 times greater.
  • 6.0% to 6.4%, the risk was 29.3 times greater.
  • 6.5% to 6.9%, the risk was 28.2 times greater.
  • >7.0%, the risk was 81.2 times greater.
These researchers also investigated whether HbA1c levels in non-diabetic women could predict cardiovascular disease (CVD) in the following 10 years. They found that HbA1c did not predict CVD.

1 Hemoglobin A1c Predicts Diabetes but Not Cardiovascular Disease in Nondiabetic Women