High HbA1c levels a modifiable predictor of microalbuminuria

Poor glycemic control may be the only modifiable predictor of the development of microalbuminuria in childhood onset type 1 diabetes.

To assess independent predictors for the development of microalbuminuria and progression to macroalbuminuria, researchers from the United Kingdom conducted a prospective observational study in 527 patients with type 1 diabetes who were diagnosed at a mean age of 8.8 years. The patients were followed up for 9.8 years.

After 10 years of diabetes, cumulative prevalence of microalbuminuria was 25.7% (95% CI, 21.3% to 30.1%) and after 19 years, 50.7% (40.5% to 60.9%). High HbA1c concentrations were the only modifiable adjusted predictor for microalbuminuria, according to the researchers. They found a 35% increased risk for a 1% rise in HbA1c.

Progression from microalbuminuria to macroalbuminuria occurred at a mean age of 18.5 years. Cumulative prevalence of progression from microalbuminuria to macroalbuminuria was 13.9%. The researchers concluded that poor glycemic control and microalbuminuria, whether persistent or intermittent, were the only modifiable predictors of macroalbuminuria. – by Stacey L. Adams

BMJ. 2008;336:697-701.

The importance of this paper is that this trial was prospective. It was done by a good group of investigators who started off with a pretty large cohort. It is a fairly recent study, so it comes at a time when we have been able to improve glucose control through careful monitoring — which we could not do 25 to 30 years ago — and we have newer insulins. Despite all of that, the one thing they were able to identify that leads to diabetic neuropathy is poor glycemic control. That is the most important thing. They looked at smoking, high blood pressure and blood glucose control and the thing that stood out, the one consistent factor, was blood glucose control.

– Mark Sperling, MD

Endocrine Today Editorial Board member