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.


A. Karwath: None. J.A. Williams: None. R.A. Round: None. G. Gkoutos: None. G. Roberts: None. J. Webber: None.


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)

Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. More information is available at