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CLINICAL TESTS IN THE VAT TRAP SERIES
Discuss this list with your doctor
These are the clinical tests referenced throughout the book series — what each one measures, why it matters, and where you can usually obtain it. Availability and cost vary by country.
FREE TOOLS
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Three browser-based calculators built around the measurements that actually matter. No signup required.
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TIER I ·
Start at home or with your GP
The simplest tests are also the most useful.The four measurements below give a remarkably complete picture of cardiometabolic risk — and all are accessible without a specialist referral.
BLOOD PRESSURE
The single most important modifiable cardiovascular risk factor. One-off readings in a clinic miss the daily and weekly pattern — home monitoring gives a more accurate picture and is far better at flagging early hypertension.
Available from most pharmacies and GP/family doctor surgeries, but also easy and low cost to measure at home. Many NHS GPs and some newer pharmacy initiatives now offer ambulatory (24-hour) BP monitoring on referral. A validated home arm cuff costs from around £25; cuffless wrist monitors (Hilo) are an emerging higher-end option for continuous tracking.
WHERE TO OBTAIN IT
Blood pressure
GLYCAEMIC BASELINE
HbA1c
A blood test that reflects average glucose exposure over the previous three months. The international standard for diagnosing pre-diabetes ("non-diabetic hyperglycaemia") and diabetes.
WHERE TO OBTAIN IT
Available through GPs (often included in routine bloods after 40), online pathology services such as Medichecks, Thriva or Randox, and at many UK pharmacies via finger-prick testing.
YOUR WAIST
Waist measurement
Because your waist is a simple measurement that correlates well with visceral adipose tissue it is a very useful metric to track.
HOW TO MEASURE IT
During weight loss, GLP-1s or body recomposition programme you should measure your waist and weight each week and record in a diary such as our N-of-1 tracker to share with your prescribing team. Use a measuring app to make this easier
GLUCOSE DYNAMICS
Continuous glucose monitor (CGM)
A small sensor worn on the upper arm for around 14 days, recording glucose every few minutes. Originally developed for diabetes management, it picks up transient post-meal glucose spikes that a normal HbA1c can miss entirely.
WHERE TO OBTAIN IT
Now available over-the-counter in the UK (Abbott Libre Rio, Dexcom Stelo) and in many countries internationally — no prescription required. Typical cost £50–£100 for a two-week sensor.
TIER II · MODERN BLOOD TESTS
The lipid tests routine panels often miss
The basic NHS lipid panel typically reports only total cholesterol, HDL and non-HDL cholesterol — sometimes including LDL. The two tests below sit alongside that panel and refine cardiovascular risk substantially. They are not yet routine, but most GPs and online labs will run them on request.
PARTICLE COUNT
Apolipoprotein B - (ApoB)
A blood test measuring the total number of atherogenic lipoprotein particles. A more accurate marker of cardiovascular risk than LDL cholesterol alone — particularly important in patients with metabolic risk (overweight, raised VAT). The ratio of LDL to ApoB is also informative.
WHERE TO OBTAIN IT
Through GPs on request, and via online pathology services. Not yet routine on the NHS lipid panel but increasingly recognised in international guidelines.
ONCE-IN-A-LIFETIME TEST
Lipoprotein(a) - (Lp(a))
An independently inherited lipoprotein that is strongly atherogenic. Affects roughly one in five adults; significantly raises the risk of coronary disease and stroke regardless of LDL level. Because the level barely changes, this test only needs to be done once.
WHERE TO OBTAIN IT
On the NHS, Lp(a) is generally available only via specialist lipid clinics on referral. Otherwise through GPs on request, online pathology services (Medichecks, Thriva, Randox), or as part of a cardiologist-reported postal panel. New Lp(a)-lowering drugs are in late-stage trials.
TIER III · STANDARD IMAGING
Imaging widely available at most modern centres
The two scans below are increasingly mainstream and available at most modern CT and DEXA facilities — both NHS and private — across the UK and internationally.
CORONARY PLAQUE BURDEN
Coronary artery calcium score (CAC)
A non-contrast CT scan of the heart that detects microscopic coronary calcification — a marker of established coronary atherosclerosis. Most modern CT scanners (16-slice or higher) can perform this with the right protocol and scoring algorithm.
WHERE TO OBTAIN IT
The lowest-cost basic cardiac CT — widely offered at private imaging centres in the UK and internationally, and especially accessible in the USA where it can be obtained for under $100. On the NHS, CAC scanning is not available on a health screening basis; it is provided only as part of the investigation of symptoms.
BODY COMPOSITION
DEXA scan
A low-dose dual-energy x-ray scan that measures body fat distribution, bone mineral density, and skeletal muscle mass. Provides a useful estimate of visceral fat (VAT) and is the standard test for tracking lean muscle alongside weight change.
WHERE TO OBTAIN IT
Widely available at private clinics, hospital radiology departments, and sports medicine centres in the UK and internationally. Typical cost £75–£200.
TIER IV · ADVANCED IMAGING
Specialist tests for detailed risk stratification
The four scans below sit at the modern edge of cardiovascular and metabolic imaging. They are not available everywhere, but are increasingly offered at specialist cardiology centres in the UK, USA, Europe, Australia and elsewhere.
CORONARY ANATOMY
CT coronary angiogram (CTCA)
A contrast-enhanced CT of the coronary arteries — higher dose and more detailed than a CAC score, requiring workstation analysis and cardiology or radiology review. Detects both calcified and non-calcified plaque and can distinguish high-risk from low-risk plaque features. Now the standard test for the investigation of chest pain, with sensitivity equivalent to invasive coronary angiography.
WHERE TO OBTAIN IT
Available at most large NHS hospitals as part of the investigation of cardiac symptoms (not offered for screening), and at private cardiology imaging centres internationally.
FLOW ANALYSIS
CT-FFR (HeartFlow)
AI-based analysis applied to CTCA data to generate a coronary blood-flow map. Improves the specificity of CTCA — which is otherwise prone to false-positive readings, often caused by blooming artefact from heavy coronary calcification — and reduces the number of patients sent on for unnecessary invasive angiography. Developed by HeartFlow (Stanford, USA).
WHERE TO OBTAIN IT
Increasingly available across NHS cardiology services and at private centres in the UK, USA, Europe, Japan and elsewhere. Add-on to an existing CTCA.
CORONARY INFLAMMATION
Fat Attenuation Index (FAI)
AI-based analysis applied to CTCA data to generate a coronary blood-flow map. Improves the specificity of CTCA — which is otherwise prone to false-positive readings, often caused by blooming artefact from heavy coronary calcification — and reduces the number of patients sent on for unnecessary invasive angiography. Developed by HeartFlow (Stanford, USA).
WHERE TO OBTAIN IT
Available where CTCA data is sent to Caristo for analysis.
Licensed in the UK, Europe, Australia and New Zealand. Awaiting FDA approval in the USA.
VISCERAL FAT MEASUREMENT
CT or MRI for VAT
A cross-sectional scan at the level of the abdomen — the gold-standard technique for measuring how much of the waist circumference is subcutaneous fat versus visceral adipose tissue (VAT). Useful for risk stratification and for selecting drug therapies such as GLP-1 receptor agonists.
WHERE TO OBTAIN IT
Most modern CT or MRI scanners can perform this with the appropriate protocol — ask any radiology centre. Sometimes offered as an add-on to a CAC or CTCA appointment.
