New Diabetes Diagnostic Threshold of Hemoglobin A1c and the 3-Year Incidence of Retinopathy
Tsugawa Y et al. – The longitudinal results support the validity of the new hemoglobin A1c threshold of 6.5% or higher for diagnosing diabetes.Methods
- The authors analyzed longitudinal data of 19,897 Japanese adults who underwent a health checkup in 2006 and were followed-up 3 years later.
- They used logistic regression models and restricted cubic spline models to examine the relationship between baseline hemoglobin A1c levels and the prevalence and the 3-year incidence of retinopathy.
- The restricted cubic spline model indicated a possible threshold for the risk of incident retinopathy at hemoglobin A1c levels of 6.0–7.0%.
- Logistic regression analysis found that individuals with hemoglobin A1c levels of 6.5–6.9% were at significantly higher risk of developing retinopathy at 3 years compared with those with hemoglobin A1c levels of 5.0–5.4% (adjusted odds ratio, 2.35 [95% CI 1.08–5.11]).
- Those with hemoglobin A1c levels between 5.5 and 6.4% exhibited no evidence of elevated risks.
- They did not observe a threshold in the analysis of prevalent retinopathy.