Cardiovascular disease (CVD) biomarkers

Cardiovascular disease (CVD) is an umbrella term that includes heart, stroke, and blood vessel diseases. In 2024, CVD contributed to almost 12% of the total burden of disease (AIHW 2024). and was attributed to one in four deaths. Ischaemic heart diseases and cerebrovascular diseases were the number one and number three leading causes of death in Australia in 2023, see Causes of Death, Australia, 2023. There are many risk factors for CVD including high cholesterol, high blood pressure, and smoking (AIHW 2024).

The indicators of CVD that were measured include:

• total cholesterol
• high density lipoprotein (HDL) cholesterol
• low density lipoprotein (LDL) cholesterol
• triglycerides.

These indicators, along with self-reported use of cholesterol medication, were used to derive dyslipidaemia status. Self-reported data on CVD was collected in the survey components of the IHMHS and can be used for comparison.

Cut-off reference values for normal and abnormal results were sourced from the current Royal College of Pathologists of Australasia Manual for pathology tests, which refers to the 2012 National Vascular Disease Prevention Alliance guidelines for the management of absolute risk of cardiovascular disease (NVDPA 2012; RCPA 2024). Results for CVD indicators were collected for children aged 12–17 years, but there are no agreed cut-offs for reporting these results as normal or abnormal.

Laboratory test information, including analysis methods and machines used to measure CVD biomarkers, is available from the Downloads page.

This is the second time the ABS has collected information on total cholesterol, HDL cholesterol, LDL cholesterols and triglycerides. Information on these biomedical indicators was previously collected in the NHMS 2011–12 and the NATSIHMS 2012–13. Apolipoprotein B was measured in previous collections; however, it was not measured in the NHMS 2022–24 or the NATSIHMS 2022–24. For information on time series comparability, see Comparing biomedical collections over time.

Total cholesterol, HDL cholesterol, LDL cholesterols and triglycerides 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.

Cholesterol (a waxy, fat-like substance) is a lipid that is necessary to make hormones and vitamin D, and also assists in digestion. The body can produce its own cholesterol, and it is present in some foods. A person with high cholesterol can develop fatty deposits in their blood vessels increasing their risk of heart attacks or strokes (Heart Foundation 2024b). Total cholesterol includes both HDL and LDL cholesterol.

Total cholesterol results were obtained for persons aged 12 years and over who provided a blood sample. Fasting was not required for this test.

Total cholesterol levels were measured at the Douglass Hanly Moir Pathology (DHM) laboratory using the cholesterol oxidase/peroxidase method. The total cholesterol test measures the combined amount of lipid (fat) components circulating in the blood at the time of the test, expressed as mmol/L.

The following cut-offs were used for serum total cholesterol:

• normal total cholesterol levels <5.5 mmol/L
• abnormal total cholesterol levels ≥5.5 mmol/L.

Therapeutic levels for treatment of individuals at high risk of cardiovascular disease used by health professionals are not the same as the reference ranges used to report pathology results for the general population with no risk factors. For example, the therapeutic level for total cholesterol for individuals being considered for lipid management due to high risk of cardiovascular disease is <4.0 mmol/L (CA/DHAC 2023; Heart Foundation 2024a).

Points to be considered when interpreting data for this topic include the following:

• Total cholesterol results do not confirm a specific diagnosis without consultation with a health professional.
• Age, sex and taking lipid lowering medications are all variables that may affect lipid and lipoprotein levels. As a result, the data should be interpreted with care.
• There are several different test methods for measuring total cholesterol, which may produce different results. The data from this topic should therefore be used with caution when comparing total cholesterol results from other studies using a different test method.
• Total cholesterol is not necessarily the best measure of risk for CVD in isolation. It is one component used in the 2023 Australian CVD risk calculator (CA/DHAC 2023).

High-density lipoprotein (HDL), sometimes known as 'good' cholesterol, picks up excess cholesterol in the blood and takes it to the liver where it is broken down. Low levels of HDL cholesterol may increase the risk of CVD (AIHW 2024; CA/DHAC 2023; Heart Foundation 2024b).

HDL cholesterol results were obtained for persons aged 12 years and over who provided a blood sample. Fasting was not required for the HDL test.

HDL cholesterol levels were measured at the DHM laboratory by the enzymatic method plus accelerator selective detergent. The HDL cholesterol test measures the amount of ‘good’ cholesterol circulating in the blood at the time of the test, expressed as mmol/L.

Two different cut-off points are available for HDL cholesterol for the general population, non-sex dependant and sex dependant (RCPA 2024). The following cut-offs were used for serum HDL cholesterol:

Points to be considered when interpreting data for this topic include the following:

• HDL cholesterol results do not confirm a specific diagnosis without consultation with a health professional.
• Age, sex and taking lipid lowering medications are all variables that may affect lipid and lipoprotein levels. As a result, the data should be interpreted with care.
• There are several different test methods for measuring HDL cholesterol, which may produce different results. The data from this topic should therefore be used with caution when comparing HDL cholesterol results from other studies using a different test method.
• Two cut-off points for reporting HDL levels have been provided, one that is non-sex dependant and one that is sex dependant. Users of the data may choose to use these different cut-off points for comparability with other health surveys.
• HDL cholesterol is not necessarily the best measure of risk for CVD in isolation. It is one component used in the 2023 CVD risk calculator (CA/DHAC 2023).

Low-density lipoprotein (LDL), sometimes known as ‘bad’ cholesterol, can leave fatty deposits in the blood vessels called plaque. Too much plaque leads to blockages that prevent the passage of blood flow. High levels of LDL cholesterol may increase the risk of cardiovascular disease (AIHW 2024; CA/DHAC 2023; Heart Foundation 2024b).

Points to be considered when interpreting data for this topic include the following:

• LDL cholesterol results do not confirm a specific diagnosis without consultation with a health professional.
• Age, sex and taking lipid lowering medications are all variables that may affect lipid and lipoprotein levels. As a result, the data should be interpreted with care.
• There are several different test methods for measuring LDL cholesterol and different equations for calculating LDL cholesterol levels, which may produce different results. The data from this topic should therefore be used with caution when comparing LDL cholesterol results from other studies using a different test method.
• Persons with a triglyceride level of ≥4.5 mmol/L were excluded from the LDL cholesterol data, as the inclusion of triglyceride levels ≥4.5 mmol/L (400 mg/100 ml) will result in the generation of a false LDL cholesterol result (Friedewald et al. 1972).

Triglycerides are lipids that circulate in the blood and are the most common type of fat in the body. High levels of triglycerides, alongside high LDL cholesterol or low HDL cholesterol, can increase a person’s risk of CVD (AIHW 2024; CA/DHAC 2023; Heart Foundation 2024b).

Triglyceride results were obtained for persons aged 12 years and over who provided a blood sample. Only persons who had fasted for 8 hours or more prior to their blood test were included in data analysis; however, all triglyceride results without this exclusion are available in the DataLab microdata.

Triglyceride levels were measured at the DHM laboratory, by the Lipase/Glycerol Kinase/GPO method. The triglyceride test measures the amount of triglycerides circulating in the blood at the time of the test, expressed as mmol/L.

The following cut-offs were used for serum triglyceride levels:

• normal triglyceride levels <2.0 mmol/L
• abnormal triglyceride levels ≥2.0 mmol/L.

Points to be considered when interpreting data for this topic include the following:

• Triglyceride results do not confirm a specific diagnosis without consultation with a health professional.
• Levels of triglycerides alone are not sufficient to assess the risk of CVD.
• Age, sex and taking lipid lowering medications are all variables that may affect lipid and lipoprotein levels. As a result, the data should be interpreted with care.
• Fasting over 8 hours is required for this biomarker to accurately assess the levels of lipids (fat) circulating in the blood.
• There are several different test methods for measuring triglycerides, which may produce different results. The data from this topic should therefore be used with caution when comparing triglyceride results from other studies using a different test method.

Dyslipidaemia is a term used to describe abnormal blood lipid levels (high or low). Blood lipids are fats in the blood and include cholesterol (a fatty substance produced by the liver) and triglycerides (a key component in metabolism) (AIHW 2017). Causes may be primary (genetic) or secondary (caused by lifestyle and other factors) (Pappan et al. 2024).  

Dyslipidaemia can contribute to the development of atherosclerosis, a build-up of fatty deposits in the blood vessels. This build-up increases the risk of several cardiovascular diseases, including coronary heart disease and stroke (AIHW 2017).

A person was classified as having dyslipidaemia if they met one or more of the following conditions:

• taking lipid-lowering medication
• total cholesterol ≥5.5 mmol/L
• HDL cholesterol <1.0 mmol/L for males and <1.3 mmol/L for females
• LDL cholesterol ≥3.5 mmol/L
• triglycerides ≥2.0 mmol/L.

This definition of dyslipidaemia was used in previous ABS biomedical collections. The inclusion of total, HDL, LDL cholesterol and triglycerides cut-offs in the definition is used elsewhere, though the cut-off values may vary with each country (ESC 2019; Pappan et al 2024). Other definitions for dyslipidaemia were previously used in Australia. For example, in 2012, the National Vascular Disease Prevention Alliance defined people with dyslipidaemia as those with low HDL cholesterol in combination with high triglycerides (NVDPA 2012).

Australian Institute of Health and Welfare (AIHW) (2017), ‘Abnormal blood lipids (dyslipidaemia)’, Risk factors to health, AIHW, Australian Government, accessed 20/02/2025.

Australian Institute of Health and Welfare (AIHW) (2021), Australian Burden of Disease Study 2018: Interactive data on risk factor burden, AIHW, Australian Government, accessed 20/02/2025.

Australian Institute of Health and Welfare (AIHW) (2024), Heart, stroke and vascular disease: Australian facts, AIHW, Australian Government, accessed 17/01/2025.

Commonwealth of Australia as represented by the Department of Health and Aged Care (CA/DHAC) (2023), Australian Guideline for assessing and managing cardiovascular disease risk, AusCVDRisk, Australian Government, accessed 20/02/2025.

European Society of Cardiology (ESC) (2019), 2019 ESC/EAS Guidelines for the management of dyslipidaemias: lipid modification to reduce cardiovascular risk, European Heart Journal, 41(1):111-118, accessed 20/02/2025.

Friedwald WT, Levy RL, Fredrickson DS (1972), Estimation of the concentration of low-density lipoprotein cholesterol in plasma, without use of the preparative ultracentrifuge, Clin Chem, 18(6):499-502, accessed 20/02/2025.

Heart Foundation (2024a), Practical guide to pharmacological lipid management, Heart Foundation, accessed 20/02/2025.

Heart Foundation (2024b), Blood cholesterol, Heart Foundation website, accessed 20/02/2025.

National Vascular Disease Prevention Alliance (NVDPA) (2012), Guidelines for the management of 
absolute cardiovascular disease risk [PDF 4458 KB], Heart Foundation, accessed 20/02/2025.

Pappan N, Awosika AO, Rehman A (2024), ‘Dyslipidaemia’, StatPearls, accessed 20/02/2025.

Royal College of Pathologists of Australasia (RCPA) (2024), ‘Cholesterol’, RCPA Manual, RCPA website, accessed 20/02/2025.