Endocrine Abstracts

Introduction: Several studies have described ethnic differences in HbA1c. Non-Caucasian patients have been found to have a higher HbA1c than the Caucasian ones. These differences have often been attributed to disparities in access to medical care or quality of the care. However differences in HbA1C in ethnic minorities could also relate to biological factors so we looked at mean levels of glycaemia. The aim of our study was to observe if there is a similar correlation between HbA1c and mean glucose among different ethnicities and if, at the same level of mean glucose, the HbA1c of Non-Caucasian patients was higher than the Caucasian ones.

Methods: We enrolled 179 patients with type 1 and type 2 diabetes (35.19% blacks and 64.81% whites) from 3 different hospitals of London who had checked the glycaemia at least twice a day. From each patient’s history we chose a HbA1c value and, starting from the date of that value, we collected, via Diasend®, the correspondent mean glucose of the previous 3 months.

Results: Mean HbA1c of non-caucasian patients was 8.88±1.69 while caucasian patients’ mean HbA1c was 8.17±1.17.(P 0.001). Differences between mean glycaemia of caucasian and non caucasian patients was not statistically significant: 11.06 mmol/l±2.3 for blacks vs 10.9±2.27 for whites (P 0.83). The correlation between linear regression showed that at a same level of mean glycaemia black patients have higher HbA1c than white patients (P <0.001) and that this difference doesn’t change if the disease duration changes. (P <0.01)

Conclusions: In the group of black patients with diabetes the HbA1C was higher than other groups for a similar level of mean glucose. This could indicate that there are other factors that may influence the final value of Hba1c in this ethnic group (interindividual variation in red cells turnover, genetic variation in haemoglobin glycation).