FASTING PLASMA GLUCOSE
Plasma glucose, in simple terms, is sugar in the blood. Plasma glucose is converted into energy in the body by a hormone called insulin. However, people with diabetes do not produce sufficient insulin, therefore plasma glucose is not converted into energy, which causes high blood sugar levels (glycemia). High levels of fasting plasma glucose may increase the risk of diabetes.
The fasting plasma glucose test measures the amount of glucose (sugar) circulating in the blood at the time of the test.
Fasting plasma glucose test results were obtained for persons aged 12 years and over, who agreed to participate in the National Health Measures Survey (NHMS) and who fasted for 8 hours or more prior to providing a blood sample.
A blood sample was collected from participants and fasting plasma glucose levels were measured at the Douglass Hanly Moir (DHM) laboratory.
In the NHMS cut off reference values for normal and abnormal results were sourced from World Health Organization (WHO) guideines.1 These guidelines are based on epidemiological data and publications of major clinical trials.
In the NHMS, the following definitions were used for fasting plasma glucose:
- Normal fasting plasma glucose levels < 6.1 mmol/L indicates a person does not have diabetes
- Fasting plasma glucose levels between 6.1 to < 7.0 mmol/L indicates a person is at high risk of having diabetes
- Abnormal fasting blood glucose levels ≥ 7.0 mmol/L indicates a person has diabetes.
In the NHMS, the fasting plasma glucose results, in addition to the self reported data on diabetes, were used to estimate the prevalence of diabetes and information on diabetes management in Australia. Information about the definitions for measuring diabetes is available from the Diabetes biomarkers
topic page of this chapter.
Further test information about the analysis method and machine used to measure fasting plasma glucose levels is available in Excel spreadsheet format in the Downloads
page of this product.
The data items and related output categories for this topic are available in Excel spreadsheet format from the Downloads
page of this product.
Points to be considered when interpreting data for this topic include the following:
Comparability with other surveys
- Fasting plasma glucose results do not confirm a specific diagnosis without consultation with a health professional.
- It should be noted that the fasting plasma glucose results, on their own, do not satisfy the definition of diabetes in the NHMS. Information about the definitions for measuring diabetes is available from the Diabetes biomarkers topic page of this chapter.
- Other studies have reported fasting plasma glucose test results using 2 hour fasting blood samples. As a result, the data should be interpreted with care.
- In the NHMS, fasting plasma glucose results were not collected using the Oral Glucose Tolerance Test (OGTT). According to WHO, without this measurement, Impaired Fasting Glucose (IFG) or Impaired Glucose Tolerance (IGT) cannot be accurately determined. As a result, the data should be interpreted with care.1
- There are a number of different test methods for measuring fasting plasma glucose, which may produce different results. The data from this topic should therefore be used with caution when comparing fasting plasma glucose results from other studies using a different test method or equation.
The NHMS is the first ABS survey to collect biomedical data on diabetes.
Diabetes data has been collected in other non-ABS surveys. However, caution must be taken when interpreting results due to the differences in scope, assay and the instrument used, and any thresholds applied in the final analysis. Further information about these comparisons is available from the Comparisons with other Australian surveys
section of the Biomedical Results for Chronic Diseases, 2011-12
World Health Organization 2006, Definition and diagnosis of diabetes mellitus and intermediate hyperglycemia
>, Last accessed 16/07/2013.