Relationship between glycosylated haemoglobin and mean plasma glucose concentration in cystic fibrosis.
BACKGROUND
HbA(1c) is recommended for monitoring glycaemic control in people with cystic fibrosis-related diabetes (CFRD). However the relationship between HbA(1c) and mean plasma glucose concentration (MPG) has not been established in CFRD, as in other forms of diabetes mellitus.


METHODS
20 people (13 male, 29.7+/-8.8 years, 10 CFRD) with cystic fibrosis (CF) underwent HbA(1c) measurement and 48 h continuous glucose monitoring for estimation of MPG. The relationship between HbA(1c) and MPG was established and compared to the reported relationship for type 1 diabetes.


RESULTS
HbA(1c) was strongly correlated with MPG (R(2)=0.888, p<0.0001) in CF. The relationship of MPG to HbA(1c) was described by the equation MPG=(1.47xHbA(1c))-1.15, giving a 1.47 mmol L(-1) change in MPG per 1% change in HbA(1c). This equation predicts that MPG in people with CF and HbA(1c) <7.0% will be similar to MPG in people with type 1 diabetes who achieve the same HbA(1c) target.


CONCLUSIONS
These results imply that HbA(1c)<7.0% will predict good blood glucose control in CF as in type 1 diabetes. However, although HbA(1c) predicts complications in type 1 diabetes, further studies are required to establish the relationship between HbA(1c) and diabetic complications in people with CFRD.
Brennan
Amanda L
AL
Cardiac and Vascular Sciences (Respiratory), St George's, University of London, Cranmer Terrace, London, SW17 0RE, UK.
Gyi
Khin M
KM
Wood
David M
DM
Hodson
Margaret E
ME
Geddes
Duncan M
DM
Baker
Emma H
EH
D000328:Adult; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism*; D003550:Cystic Fibrosis / Q000097:blood* / Q000150:complications; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D008297:Male; D011379:Prognosis; D012720:Severity of Illness Index
D015415:Biomarkers; D001786:Blood Glucose; D006442:Glycated Hemoglobin