SA JOURNAL OF DIABETES & VASCULAR DISEASE
REVIEW
VOLUME 7 NUMBER 3 • SEPTEMBER 2010
99
International expert committee recommends new role for
HbA
1c
in diagnosing diabetes
Michael Kirby
Introduction
G
lycated haemoglobin – HbA
1c
, or A
1c
as it is now being called
– should be used to diagnose diabetes, according to a recent
recommendation from an international expert committee
appointed by the American Diabetes Association, the International
Diabetes Federation and the European Association for the Study of
Diabetes. This review explores the basis for this recommendation,
looking at why HbA
1c
would provide a more accurate measure for
diagnosing diabetes than glucose tests and what the change would
mean in clinical practice.
The recommendation that HbA
1c
should replace glucose
tolerance tests in the diagnosis of diabetes was made at the recent
American Diabetes Association annual meeting and published in
the July edition of
Diabetes Care
. Convened in 2008, the expert
committee that wants to redefine the diagnosis of diabetes in non-
pregnant individuals included members appointed by the American
Diabetes Federation, the European Association for the Study of
Diabetes and the International Diabetes Federation. Although it has
not yet been finalised by the commissioning organisations, the high
level nature of the committee suggests that their recommendation
is likely to be adopted.
The size of the problem
Diabetes is a significant and increasing health problem that leads
to serious complications and reduced quality of life, as well as
increased healthcare costs. In 2008, the average UK prevalence of
diabetes was estimated at 3.86% and the diagnosed population
at 2.5 million people.
1
With a growing aging population and
increasing rates of obesity, diabetes prevalence in England is
predicted to reach 5.05% by 2010.
2
Diabetes accounts for around
5% of all NHS expenditure, with much spent on avoidable diabetic
complications.
3
The importance of early diagnosis
Type 1 diabetes is often promptly and easily diagnosed on classical
symptoms and acutely elevated blood glucose concentrations.
Type 2 diabetes develops more gradually and typically involves
a long asymptomatic period, which may result in a significant
number of people with frank disease, or indicators of impaired
glucose metabolism who are risk of developing type 2 diabetes
(prediabetes), remaining undiagnosed.
Hyperglycaemia has direct and indirect effects on the human
vasculature, which are the main cause of morbidity and mortality
in type 1 and type 2 diabetes.
4
Even mildly raised glycaemia can
have damaging effects in the long term, so early diagnosis and
treatment is important. Early diagnosis is also cost-effective because
the presence of diabetic complications has been shown to increase
NHS costs more than five-fold.
5
Barriers to the early detection of type 2 diabetes
A significant barrier to improving the early detection of type
2 diabetes has been inadequate screening using tests that are
Correspondance to: Michael Kirby
Visiting Professor, Faculty of Health and Human Sciences, Centre for Research
in Primary and Community Care (CRIPACC), and the Clinical Trials Coordinat-
ing Centre, University of Hertfordshire, Hatfield, UK.
S Afr J Diabetes Vasc Dis
2010;
7
: 99–101
Figure 1.
Experts are recommending HbA
1C
for diagnosing diabetes.
Michael Kirby
