Medical conditions can affect haematological factors altering relationship between HbA1c and glucose. Patients were recruited at hospital over 3 visits (*1/**2&3 only) comprising 20 with diabetes and in Fig 1 with liver disease (LD) & hepatitis C (HC) on ribavirin*, on dapsone*, with macrocytosis, and in Fig 2 LD & HC off ribavirin**, LD with nonalcoholic steatohepatitis and cirrhosis, rheumatoid arthritis, renal disease on erythropoietin (EPO) , renal disease off EPO and with microcytosis. Glucose and full blood count were measured with HbA1c on Tosoh G8 analysers, ref range 20-42mmol/mol.

In Fig 1 HbA1c was more depressed relative to glucose than Fig 2, both p<0.001, with a combination of lower red blood cell (rbc) count & higher mean cell volume. The macrocytic nature of rbc implies faster turnover and less contact of haemoglobin with circulating glucose.

Disclosure

A. Karwath: None. J.A. Williams: None. R.A. Round: None. G. Gkoutos: None. G. Roberts: None. J. Webber: 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 (Grant agreement ID 965286)

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