Diabetes Management News and Views

The 46th Annual Meeting of the European Association for the Study of Diabetes took place 20th – 24th September in Stockholm, Sweden. Presentations at the meeting included ‘WHO new diagnostic criteria 2010′ and several short presentations on ‘HbA1c for diabetes mellitus diagnosis: need for reassessment’.

As a measure of glycaemia, HbA1c is less variable within and between individuals than measures of acute glucose control
Rohlfing et al.Clin Chem 2002;48:1116

The WHO Guidelines on What Diagnostic Tests Should be Used to Define Glycaemic Status are now about ten years old. Since their publication, the HbA1c test has been standardised – >99% of assays in US and Europe are standardised by the NGSP program to the DCCT standard.

Type 2 diabetes onset can be subtle, without symptoms and without a clear separation of glucose values from the non-diabetic distribution. Glucose levels fluctuate extensively within the day and between days, and also in response to stress.

“There is no clear division between diabetics and non-diabetics in their FPG (fasting plasma glucose) concentration or their response to an oral load.”
National Diabetes Data Group, Diabetes 1979;28: 1039-57

The WHO Guidelines on What Diagnostic Tests Should be Used to Define Glycaemic Status show that fasting plasma glucose will fail to diagnose approximately 30% of people with diabetes.

The WHO Guidelines on What Diagnostic Tests Should be Used to Define Glycaemic Status state:

Glucose should be measured immediately after collection by near patient testing, or if a blood sample is collected, plasma should be separated immediately, or the sample should be collected into a container wih glycolytic inhibitors (e.g. NaF) and placed on ice-water until separated prior to analysis.

The NHS document Putting Prevention First states, in the section on diabetes risk assessment, that either a fasting plasma glucose (FPG) or an HbA1c test can be used to identify those at high risk of developing or having diabetes.

A unique longitudinal study was published in the New England Journal of Medicine earlier this year about the advantages of HbA1c over fasting glucose.