133-LB: relationship of HbA1c and glucose by ethnicity in UK Biobank

The UK Biobank recruited 502,481 people aged 40 to 70 years who were invited to participate by post so not necessarily representative of the general population. The 405,363 participants with random glucose, HbA1c and the necessary demographic/clinical data were aged 56.5 (8.09) years, mean SD, with 54% female, and ethnicity 95.0% White W, 1.9 South Asian SA, 1.3% Black B, 0.9% Other O, 0.6% Mixed Background MB, and 0.3% Chinese C. Glucose was measured by hexokinase and HbA1c by BioRad VARIANT II TURBO analysers, reference range 20-42 mmol/mol in a dedicated central laboratory. Cohen's D statistic was used to compare glucose/HbA1c by ethnicity versus the largest group W. Mean glucose ranged from 5.04 to 5.41 mmol/L with HbA1c40.7 mmol/mol for SAversus36.0 for W (D=0.78 medium effect M) , B 39.3 (D=0.51 M) , O 38.4 (D=0.37 small S) , C 37.1 (D=0.17 very small V) & MB 36.6 (D=0.09 V) , all p values <0.001. There were large differences by ethnicity in linear regression slopes for the glucose/HbA1c relationship when compared to W with correlation coefficient comparison Z-statistics for SA 16.74, B 8.69, O 10.94, C 8.96, all p<0.001, except for MB 2.56, p=0.01. Such ethnic differences in HbA1c have been reported previously and questions raised as whether different cut-offs should be used for diagnosis of diabetes. However, more information on the prevalence of microvascular complications and differences in haematological profiles is required for such modifications. Disclosure J. A. Williams: None. S. E. Manley: n / a. A. Karwath: None. R. A. Round: None. I. M. Stratton: None. S. Ghosh: Other Relationship; Boehringer Ingelheim International GmbH, Eli Lilly and Company, Novo Nordisk. S. Mostafa: None. G. Roberts: None. J. Webber: None. G. Gkoutos: None. Funding Medical Research Council (MR/S003991/1) , MRC HDR UK (HDRUK/CFC/01) , NIHR Birmingham ECMC, NIHR Birmingham SRMRC, Nanocommons H2020-EU (731032) , MAESTRIA (965286)