What are the diagnostic guidelines for Metabolic Syndrome (Mets) workup?

From the Guidelines

Metabolic Syndrome (Mets) diagnostic guidelines are based on a cluster of disorders that include abdominal obesity, insulin resistance, dyslipidaemia, and hypertension.

Diagnostic Criteria

The criteria for clinical diagnosis of Mets are:

• Elevated waist circumference with cut-off points according to population- and country-specific definitions
• Elevated triglycerides with cut-off point ≥150 mg/dL
• Reduced HDL-cholesterol with cut-off points <50 mg/dL in females and <40 mg/dL in males
• Elevated blood pressure with cut-off points ≥130 mmHg for systolic and/or ≥85 mmHg for diastolic blood pressure
• Elevated fasting glucose with cut-off point ≥100 mg/dL 1

Additional Considerations

In children and adolescents, the definition of Mets varies, but the International Diabetes Federation recommends the following criteria:

• For children 6 years to 10 years old, obesity (defined as 90th percentile of waist circumference), followed by further measurements as indicated by family history
• For age 10 to 16 years, obesity (defined as waist circumference 90th percentile), followed by the adult criteria for triglycerides, high-density lipoprotein cholesterol (HDL-C), blood pressure, and glucose 1

Assessment and Management

A comprehensive assessment of Mets should include a more in-depth evaluation of subclinical organ damage, such as measuring ambulatory and home blood pressure, and consideration of lifestyle modifications, including a low-caloric diet and regular physical exercise 1

• Key features of Mets management include:

• Reduction in body weight by 7-10% over 6-12 months
• Low intake of saturated fats, trans-fatty acids, cholesterol, and simple carbohydrates
• Increased consumption of fruits, vegetables, and whole grains
• Regular exercise, such as a minimum of 30 minutes of daily moderate physical activity

• Pharmacological treatment should be considered in patients with hypertension, dyslipidaemia, or diabetes, and may include blockers of the renin-angiotensin system, calcium antagonists, or low-dose thiazide diuretics 1

From the Research

Diagnostic Guidelines for Metabolic Syndrome (Mets) Workup

The diagnostic guidelines for Metabolic Syndrome (Mets) workup involve various criteria and biomarkers. The following are some of the key points to consider:

• The US National Cholesterol Education Programme Adult Treatment Panel III (NCEP ATP III) guidelines define Mets as the presence of three or more of the following conditions: waist circumference > or = 88 cm, blood pressure > or = 130/85 mmHg, fasting plasma triglycerides > or = 150 mg/dl, high density lipoprotein (HDL) cholesterol < 50 mg/dl, and glucose > or = 110 mg/dl or subjects receiving treatment for their condition 2.
• The International Diabetes Federation (IDF) definition is also commonly used, which requires the presence of central obesity (waist circumference > or = 94 cm for men and > or = 80 cm for women) plus any two of the following: triglycerides > or = 150 mg/dl, HDL cholesterol < 40 mg/dl for men and < 50 mg/dl for women, blood pressure > or = 130/85 mmHg, and fasting plasma glucose > or = 100 mg/dl 3.
• Other criteria, such as the EGIR, AACE, and Barbosa et al. (2006) definitions, may also be used, but the IDF and NCEP ATP III definitions are more commonly accepted 3.
• Blood-based biomarkers, such as leptin, total adiponectin, high molecular weight (HMW) adiponectin, and their ratio, may also be useful for Mets diagnosis 4, 5.
• The choice of diagnostic criteria may depend on the population being studied and the specific risk factors being assessed 6.

Biomarkers for Metabolic Syndrome Diagnosis

Some of the key biomarkers for Mets diagnosis include:

• Leptin: higher levels are associated with Mets 5
• Adiponectin: lower levels (< 4 μg/ml) are associated with Mets 5
• High molecular weight (HMW) adiponectin: lower levels (< 2.5 μg/ml) are associated with Mets 5
• Leptin to adiponectin ratio: a higher ratio is a better biomarker for Mets diagnosis than leptin and adiponectin separately 5

Comparison of Diagnostic Criteria

The different diagnostic criteria for Mets may have varying levels of sensitivity and specificity. For example:

• The IDF definition has a sensitivity of 95.1% and a specificity of 100% 3
• The NCEP ATP III definition has a sensitivity of 35.1% and a specificity of 100% 2
• The EGIR definition has a sensitivity of 15% and a specificity of 100% 3