Metabolic Syndrome Workup

Updated: Oct 17, 2019
  • Author: Stanley S Wang, JD, MD, MPH; Chief Editor: Yasmine S Ali, MD, FACC, FACP, MSCI  more...
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Workup

Approach Considerations

Initial laboratory studies in patients suspected of having metabolic syndrome should include standard chemistries to assess for hyperglycemia and renal dysfunction and lipid studies to assess for hypertriglyceridemia or low HDL levels.

If a family history of early coronary or other atherosclerotic disease is present, consider including, in addition to HDL-C and low-density lipoprotein cholesterol (LDL-C), studies of lipoprotein(a), apolipoprotein-B100, high-sensitivity C-reactive protein (CRP), and (if the patient does not already merit the lowest LDL-C target [< 70]), homocysteine and fractionated LDL-C.

In view of the various associations between metabolic syndrome and other conditions discussed elsewhere in this article, additional helpful blood tests may include thyroid and liver studies, hemoglobin-A1C levels, and uric acid. Increased thyroid stimulating hormone (TSH) has been linked to a higher prevalence of metabolic syndrome. [79] Hyperuricemia appears to be much more common in patients with metabolic syndrome than in the general population, and this is attributed to the inflammatory effects of metabolic syndrome. [80] Further studies should be pursued as clinical findings dictate.

Imaging studies

Imaging studies are not routinely indicated in the diagnosis of metabolic syndrome. However, they may be appropriate for patients with symptoms or signs of the many complications of the syndrome, including cardiovascular disease. Complaints of chest pain, dyspnea, or claudication may warrant additional testing with electrocardiography (rest/stress ECG), ultrasonography (vascular or rest/stress echocardiography), stress single-photon emission computed tomography (SPECT), cardiac positron emission tomography (PET), or other imaging studies.

Testing for sleep-related breathing disorder

Investigation into other causes or exacerbating factors should be considered. For example, sleep-related breathing disorders, such as obstructive sleep apnea, are becoming increasingly relevant and novel risk factors for metabolic syndrome. [2]

The difficulty in clarifying the associations between obstructive sleep apnea and metabolic syndrome lie in part with the confounding effect of obesity. [81] Nevertheless, patients reporting significant sleep disturbances, snoring, possible pauses, and/or daytime drowsiness may benefit from further investigation for a treatable sleep-related breathing disorder, including through polysomnography.

Cardiovascular risk assessment

New guidelines on the assessment of cardiovascular risk, released in late 2013 by the American Heart Association/American College of Cardiology (AHA/ACC), recommend use of a revised calculator for the risk of developing a first atherosclerotic cardiovascular disease (ASCVD) event, which is defined as one of the following in a person who was initially free from ASCVD [82] :

  • Nonfatal myocardial infarction

  • Death from coronary heart disease

  • Stroke (fatal or nonfatal)

The calculator uses 9 clinical and laboratory risk factors to determine 10-year and lifetime risk.

For patients 20-79 years of age who do not have existing clinical ASCVD, the guidelines recommend assessing clinical risk factors every 4-6 years. For patients with low 10-year risk (< 7.5%), the guidelines recommend assessing 30-year or lifetime risk in patients 20-59 years old. Regardless of the patient’s age, clinicians should communicate risk data to the patient and refer to the AHA/ACC lifestyle guidelines, which cover diet and physical activity. For patients with elevated 10-year risk, clinicians should communicate risk data and refer to the AHA/ACC guidelines on blood cholesterol and obesity. [82]