Why this one isn't just another index
Plenty of metabolic scores float around the internet with cut points nobody agreed on. This isn't one of them. In 2009 the International Diabetes Federation, the American Heart Association, the National Heart, Lung and Blood Institute, the World Heart Federation, the International Atherosclerosis Society and the International Association for the Study of Obesity published a joint statement that settled the disagreement: five components, any three of which meet the definition.
That matters because it means the thresholds here aren't an opinion. They are the numbers your doctor is also using.
The five criteria as published
| Component | Threshold | Treatment counts? |
|---|---|---|
| Waist circumference | Population- and sex-specific (see selector) | — |
| Triglycerides | ≥150 mg/dL (1.7 mmol/L) | Yes |
| HDL cholesterol | <40 mg/dL (1.0 mmol/L) men <50 mg/dL (1.3 mmol/L) women | Yes |
| Blood pressure | ≥130 systolic and/or ≥85 diastolic | Yes |
| Fasting glucose | ≥100 mg/dL (5.6 mmol/L) | Yes |
What meeting three actually means
It is not a disease diagnosis, and it is not a sentence. Metabolic syndrome is a risk clustering — a way of noticing that several things have drifted together, because they tend to share a cause and because the combination carries more risk than any one of them alone. The useful response is not alarm; it is that the same handful of levers move several of these numbers at once.
Three of the five — triglycerides, HDL and fasting glucose — are the ones that tend to respond to the same things: movement after meals, keeping muscle, fibre, sleep. If you want the graded evidence rather than the claims, that's what the Evidence Library is for. If you have fasting insulin on your panel too, the HOMA-IR calculator adds a different angle on the same question.
Take the result to your doctor rather than acting on it alone. They can see the things this page can't: your family history, your other labs, your medications, and whether any single number was a one-off.
Sources
- Alberti KGMM, Eckel RH, Grundy SM, Zimmet PZ, Cleeman JI, Donato KA, Fruchart J-C, James WPT, Loria CM, Smith SC Jr. Harmonizing the metabolic syndrome: a joint interim statement of the IDF Task Force on Epidemiology and Prevention; NHLBI; AHA; World Heart Federation; International Atherosclerosis Society; and IASO. Circulation. 2009;120:1640–1645. pubmed.ncbi.nlm.nih.gov/19805654
- Full text and criteria tables: world-heart-federation.org (PDF)