Rapid responses are electronic comments to the editor. They enable our users
to debate issues raised in articles published on bmj.com. A rapid response
is first posted online. If you need the URL (web address) of an individual
response, simply click on the response headline and copy the URL from the
browser window. A proportion of responses will, after editing, be published
online and in the print journal as letters, which are indexed in PubMed.
Rapid responses are not indexed in PubMed and they are not journal articles.
The BMJ reserves the right to remove responses which are being
wilfully misrepresented as published articles or when it is brought to our
attention that a response spreads misinformation.
From March 2022, the word limit for rapid responses will be 600 words not
including references and author details. We will no longer post responses
that exceed this limit.
The word limit for letters selected from posted responses remains 300 words.
Diabetes UK recommends that, with no symptoms, diagnosis of diabetes
should not be based on a single glucose determination but requires
confirmatory plasma venous determination. At least one additional glucose
test result on another day with a value in the diabetic range is
essential, either fasting, from a random sample or from the two hour post
glucose load. If the fasting or random values are not diagnostic the two
hour value should be used.
Diabetes UK also recommends that the diagnosis is confirmed by a
glucose measurement performed in an accredited laboratory on a venous
plasma sample, although the WHO do give values for whole blood as well.
This should mean that there is less need to perform oral glucose tolerance
testing on the majority of the population, although in the elderly and
some ethnic minority groups the fasting glucose may not be a reliable
indicator of diabetes. For this group, and in the absence of symptoms of
diabetes, Diabetes UK would recommend the use of an oral glucose tolerance
test (OGTT) as the definitive second test.
The patient presented in the consultation scenario has unequivocal
fasting hyperglycaemia, if the sample is fasting, without obvious symptoms
and is not elderly, although ethnicity is not described. In these
circumstances a repeat fasting glucose is much simpler and more convenient
for the patient and is usually enough to confirm the diagnosis of
diabetes. An audit in our region has shown that the OGTT is often
performed poorly in primary care with a wide variation in glucose loads
(65 to 85 grams of glucose) given as Lucozade. If the second fasting
plasma glucose does not confirm diabetes the OGTT by a standardised
protocol should be the definitive third line test.
My reading of the 1999 WHO guidance is that less reliance should be
placed on the OGTT than before, but this 10 minute consultation gives the
message that the OGTT is still the preferred diagnostic test. Most
patients attending our diabetes clinics with diabetes have been diagnosed
on the basis of one or two fasting or random plasma glucose tests. I
believe that the OGTT is most useful when impaired fasting glycaemia is
found to persist on a repeat measurement.
Raised blood glucose and use of the glucose tolerance test
Diabetes UK recommends that, with no symptoms, diagnosis of diabetes
should not be based on a single glucose determination but requires
confirmatory plasma venous determination. At least one additional glucose
test result on another day with a value in the diabetic range is
essential, either fasting, from a random sample or from the two hour post
glucose load. If the fasting or random values are not diagnostic the two
hour value should be used.
Diabetes UK also recommends that the diagnosis is confirmed by a
glucose measurement performed in an accredited laboratory on a venous
plasma sample, although the WHO do give values for whole blood as well.
This should mean that there is less need to perform oral glucose tolerance
testing on the majority of the population, although in the elderly and
some ethnic minority groups the fasting glucose may not be a reliable
indicator of diabetes. For this group, and in the absence of symptoms of
diabetes, Diabetes UK would recommend the use of an oral glucose tolerance
test (OGTT) as the definitive second test.
The patient presented in the consultation scenario has unequivocal
fasting hyperglycaemia, if the sample is fasting, without obvious symptoms
and is not elderly, although ethnicity is not described. In these
circumstances a repeat fasting glucose is much simpler and more convenient
for the patient and is usually enough to confirm the diagnosis of
diabetes. An audit in our region has shown that the OGTT is often
performed poorly in primary care with a wide variation in glucose loads
(65 to 85 grams of glucose) given as Lucozade. If the second fasting
plasma glucose does not confirm diabetes the OGTT by a standardised
protocol should be the definitive third line test.
My reading of the 1999 WHO guidance is that less reliance should be
placed on the OGTT than before, but this 10 minute consultation gives the
message that the OGTT is still the preferred diagnostic test. Most
patients attending our diabetes clinics with diabetes have been diagnosed
on the basis of one or two fasting or random plasma glucose tests. I
believe that the OGTT is most useful when impaired fasting glycaemia is
found to persist on a repeat measurement.
Competing interests:
None declared
Competing interests: No competing interests