A healthcare practitioner may suspect that a person has metabolic syndrome if the person has excess weight around the waist and a sedentary lifestyle, but both laboratory and non-laboratory tests are important in establishing the diagnosis. Recommended tests include:
- Glucose. Usually a fasting glucose test is performed but, in some cases, a healthcare practitioner may also order a post prandial glucose (after a meal) or a GTT (glucose tolerance test – several glucose tests that are taken before and at timed intervals after a glucose challenge). The goal of glucose testing is to determine whether a person has diabetes or a decreased ability to process glucose (impaired glucose tolerance), which can eventually result in diabetes.
- Hemoglobin A1c (HbA1c). This is a measure of glucose control and can be used for the diagnosis of diabetes.
- Lipid profile. This measures HDL, LDL, triglycerides, and VLDL. If the triglycerides are significantly elevated, a DLDL (direct measurement of the LDL) may need to be done.
There are other laboratory tests that are not recommended for diagnosing metabolic syndrome but that may ordered by some healthcare practitioners to provide additional information. They include:
- C-peptide. This is a reliable indicator of endogenous (a person's own) insulin production.
- Urine albumin. An early indicator of kidney disease, this test is used to help monitor diabetics and is recommended under the WHO criteria.
- hs-CRP. This is a measure of low levels of inflammation that may be tested as part of an evaluation of cardiac risk.
- sdLDL. This is a measurement of the number of small dense low-density lipoprotein molecules a person has. LDL varies in size, and the smaller denser molecules, which tend to form when elevated triglycerides and VLDL are present in the blood, are thought to be more aggressive in causing atherosclerosis. This test is now commercially available, but is not performed by many laboratories and is not ordered frequently. Its ultimate clinical utility has yet to be determined. It may be evaluated in a LDL particle testing.
- Blood pressure, to check for hypertension
- Weight and waist circumference, to document abdominal obesity
- BMI (body mass index), an alternate measure of obesity that is used by many healthcare practitioners; it is calculated by taking: (Weight in pounds X 705) / (height in inches squared); for example: (150 pounds X 705) / (67 inches X 67 inches) = a BMI of 23.5. An adult with a BMI greater than 30 is considered obese. This calculation does not, however, describe where the excess weight is on the body.