Glycated hemoglobin for diagnosis of diabetes in polish population of more than 45 years of age – a multicenter study

Abstract

Introduction: American Diabetes Association introduced in 2010 a new criterion for the diagnosis of diabetes - HbA1c level of ≥ 6,5%. Polish Society of Diabetology (PTD) up to now has not accepted this criterion. This study aimed to assess a concordance of this criterion with advised by the PTD glycemic criteria in the polish population.

Methods: The study was performed in the frames of the screening action „Diabetes – let’s win together!” in 10 Polish cities in subjects older than 45 years, with no previously diagnosed diabetes but with existing diabetes risk factors. The assessment of HbA1c was performed using point of care device A1cNow+ (Bayer HealthCare). In subjects with HbA1c levels of >5,6%, according to the protocol fasting plasma glucose was estimated and oral glucose tolerance test was performed.

Results: The analysis comprised 1889 subjects in whom HbA1c was estimated. The group with HbA1c ≤ 5.6% comprised 1156 subjects (it has been assumed that no one from this group suffered from diabetes), group with HbA1c 5.7-6.4% - 609 subjects, and the group with HbA1c ≥ 6.5% - 124 subjects, However in only 168 and 89 from those subjects, respectively, the diagnosis of diabetes could be confirmed or excluded according to the glycemic criteria. Sensitivity, specifity, positive and negative predictive values for HbA1c=6.5% were 0.827; 0.982; 0.753 i 0.989, respectively, whereas for HbA1c=7.5% the respective values were 0.370; 0.997; 0.882 i 0.960.

Conclusions: taking to the account only a criterion of concordance of the diagnosis (and not a criterion of possibility of development of diabetes complications) it seems that in the polish population the HbA1c threshold for the diagnosis of diabetes should be equal 7.5% rather than 6.5%