HealthDay News — For patients with type 1 diabetes, long-term weighted mean hemoglobin A1c (HbA1c) is associated with development of severe microvascular complications, according to a study in Diabetes Care.

Maria Nordwall, MD, PhD, from Linköping University in Norrköping, Sweden, and colleagues conduced a longitudinal observation study involving an unselected population of 451 patients diagnosed with type 1 diabetes during 1983 to 1987, before age 35 years.

The researchers measured HbA1c from diagnosis through 20 to 24 years of follow-up, and calculated long-term weighted mean HbA1c. Complications in relation to HbA1c levels were examined.

Continue Reading

Increasing long-term mean HbA1c correlated with sharply increased and earlier incidence of proliferative retinopathy and persistent macroalbuminuria, the researchers found. Among patients with long-term weighted mean HbA1c below 7.6%, none developed proliferative retinopathy or persistent macroalbuminuria.

Among those with long-term mean HbA1c above 9.5%, 51% developed proliferative retinopathy and 23% developed persistent macroalbuminuria.

“Keeping HbA1c below 7.6 percent (60 mmol/mol) as a treatment target seems to prevent proliferative retinopathy and persistent macroalbuminuria for up to 20 years,” the authors wrote.


  1. Nordwall M et al. Diabetes Care. 2014; doi: 10.2337/dc14-1203.