definition and diagnosis of diabetes mellitus and intermediate ...

---

definition and diagnosis
of diabetes mellitus
and intermediate
hyperglycemia
RepoRt of a WHo/IDf ConsultatIon

---

WHo library Cataloguing-in-publication Data
Definition and diagnosis of diabetes mel itus and intermediate hyperglycemia :
report of a WHO/IDF consultation.
1.Diabetes mel itus – diagnosis. 2.Diabetes mel itus - classification. 3.Hyperg-
lycemia. 4.Glucose tolerance test. I.World Health Organization. II.International
Diabetes Federation.
ISBN 92 4 159493 4

(NLM classification: WK 810)
ISBN 978 92 4 159493 6
© World Health organization 2006
Al rights reserved. Publications of the World Health Organization can be obtained
from WHO Press, World Health Organization, 20 Avenue Appia, 1211 Geneva 27,
Switzerland (tel.: +41 22 791 3264; fax: +41 22 791 4857; e-mail: bookorders@
who.int). Requests for permission to reproduce or translate WHO publications
– whether for sale or for noncommercial distribution – should be addressed to
WHO Press, at the above address (fax: +41 22 791 4806; e-mail: permissions@
who.int).
The designations employed and the presentation of the material in this publication
do not imply the expression of any opinion whatsoever on the part of the World
Health Organization concerning the legal status of any country, territory, city or
area or of its authorities, or concerning the delimitation of its frontiers or bounda-
ries. Dotted lines on maps represent approximate border lines for which there may
not yet be ful agreement.
The mention of specific companies or of certain manufacturers’ products does not
imply that they are endorsed or recommended by the World Health Organization
in preference to others of a similar nature that are not mentioned. Errors and
omissions excepted, the names of proprietary products are distinguished by initial
capital letters.
Al reasonable precautions have been taken by the World Health Organization
to verify the information contained in this publication. However, the published
material is being distributed without warranty of any kind, either expressed or
implied. The responsibility for the interpretation and use of the material lies with
the reader. In no event shal the World Health Organization be liable for damages
arising from its use.
Printed by the WHO Document Production Services, Geneva, Switzerland

---

---

contents
Summary of technical report and recommendations
1
Introduction
5
Background
7
ISSuE 1:
Should the current diagnostic criteria for diabetes be changed?
9
ISSuE 2:
How should normal plasma glucose levels be defined?
13
ISSuE 3:
How should impaired glucose tolerance be defined?
17
ISSuE 4:
How should impaired fasting glucose be defined?
21
ISSuE 5:
What diagnostic tests should be used to define glycaemic status?
29
Appendices
35
References
41

---



---

summary of
technical report
and recommendations
since 1965 the World Health organization (WHo) has published guide-
lines for the diagnosis and classification of diabetes. these were
last reviewed in 1998 and were published as the guidelines for the
Definition, Diagnosis and Classification of Diabetes Mellitus and its
Complications. since then more information relevant to the diagnosis
of diabetes has become available. In november 2005 a joint WHo and
International Diabetes federation (IDf) technical advisory Group met
in Geneva to review and update the current WHo guidelines.
After consideration of available data and recent recommendations made
by other organisations, the Group made the fol owing recommendations:

Recommendation 1 The current WHO diagnostic criteria for diabetes should be maintained
– fasting plasma glucose ≥ 7.0mmol/l (126mg/dl) or 2–h plasma glucose
≥ 11.1mmol/l (200mg/dl).
Despite the limitations with the data from which the diagnostic criteria for
diabetes are derived, the current criteria distinguish a group with signifi-
cantly increased premature mortality and increased risk of microvascular
and cardiovascular complications.

Recommendation 2 Since there are insufficient data to accurately define normal glucose lev-
els, the term ‘normoglycaemia’ should be used for glucose levels associ-
ated with low risk of developing diabetes or cardiovascular disease, that
is levels below those used to define intermediate hyperglycaemia.

Recommendation 3 The current WHO definition for Impaired Glucose Tolerance (IGT) should
be maintained for the present.
Consideration should be given to replacing this category of intermediate
hyperglycaemia by an overal risk assessment for diabetes, cardiovascular
disease, or both, which includes a measure of glucose as a continuous
variable.


---

definition and diagnosis of diabetes mellitus and intermediate hyperglycemia

Recommendation 4 The fasting plasma glucose cut-point for Impaired Fasting Glucose (IFG)
should remain at 6.1mmol/l.
This decision was based on concerns about the significant increase in IFG
prevalence which would occur with lowering the cut-point and the impact
on individuals and health systems. There is a lack of evidence of any
benefit in terms of reducing adverse outcomes or progression to diabetes
and people identified by a lower cut-point eg 5.6mmol/l (100mg/dl) have
a more favourable cardiovascular risk profile and only half the risk of
developing diabetes compared with those above the current WHO cut-
point. Lowering the cut-point would increase the proportion of people
with IGT who also have IFG but decreases the proportion of people with
IFG who also have IGT.
Consideration should be given to replacing this category of intermediate
hyperglycaemia by an overal risk assessment for diabetes, cardiovascular
disease, or both, which includes a measure of glucose as a continuous
variable.

Recommendation 5 1. Venous plasma glucose should be the standard method for measuring
and reporting glucose concentrations in blood. However in recognition
of the widespread use of capil ary sampling, especial y in under-re-
sourced countries, conversion values for capil ary plasma glucose are
provided for post-load glucose values. Fasting values for venous and
capil ary plasma glucose are identical.
2. Glucose should be measured immediately after col ection by near-pa-
tient testing, or if a blood sample is col ected, plasma should be im-
mediately separated, or the sample should be col ected into a container
with glycolytic inhibitors and placed in ice-water until separated prior
to analysis.

Recommendation 6 The oral glucose tolerance test (OGTT) should be retained as a diagnostic
test for the fol owing reasons:
■ fasting plasma glucose alone fails to diagnose approximately 30% of
cases of previously undiagnosed diabetes,
■ fan OGTT is the only means of identifying people with IGT,
■ fan OGTT is frequently needed to confirm or exclude an abnormality
of glucose tolerance in asymptomatic people.
An OGTT should be used in individuals with fasting plasma glucose 6.1–
6.9mmol/l (110–125mg/dl) to determine glucose tolerance status.


---

summary of technical report and recommendations

Recommendation 7 Currently HbA1c is not considered a suitable diagnostic test for diabetes
or intermediate hyperglycaemia.
The fol owing Table summarises the 2006 WHO recommendations for the
diagnostic criteria for diabetes and intermediate hyperglycaemia.
Diabetes
Fasting plasma glucose
≥7.0mmol/l (126mg/dl)
2–h plasma glucose*
or
≥11.1mmol/l (200mg/dl)
Impaired Glucose tolerance (IGt)
Fasting plasma glucose
<7.0mmol/l (126mg/dl)
2–h plasma glucose*
and
≥7.8 and <11.1mmol/l
(140mg/dl and 200mg/dl)
Impaired fasting Glucose (IfG)
Fasting plasma glucose
6.1 to 6.9mmol/l
2–h plasma glucose*
(110mg/dl to 125mg/dl)
and (if measured)
<7.8mmol/l (140mg/dl)
* Venous plasma glucose 2–h after ingestion of 75g oral glucose load
* If 2–h plasma glucose is not measured, status is uncertain as diabetes
or IGT cannot be excluded


---



---