Metabolic Syndrome

Diagnosis

Indications for Testing

  • Suspicion based on criteria for diagnosis – hypertension, dyslipidemia, glucose intolerance, obesity

Criteria for Diagnosis

  • National Cholesterol Education Program Adult Treatment Panel III criteria for diagnosis of metabolic syndrome (Grundy, 2005) – must meet ≥3 of the 5 criteria
    • Waist circumference – men ≥40 inches, women ≥35 inches
      • Measure at the top of the iliac crest after inspiration
    • Triglyceride concentration – ≥150 mg/dL
    • HDL-C – men <40 mg/dL, women <50 mg/dL, or individual receiving pharmacologic therapy to reduce cholesterol
    • Hypertension – BP ≥130/85 or individual receiving pharmacologic therapy for hypertension
    • Fasting blood glucose – ≥100 mg/dL (ADA guidelines, 2014)
  • Criteria for major definitions of metabolic syndrome

    Criteria for Major Definitions of Metabolic Syndrome

     

    WHO 1999

    ≥2 of the following

    NECP ATP III 2001

    ≥3 of the following

    AACE 2003

    ≥2 of the following

    IDF 2005

    ≥2 of the following

    Central obesity

    BMI >30 or waist-to-hip ratio of >0.9 for men or >0.85 for women

    WC >40 in (102 cm) for men or >35 in (88 cm) for women

    Obesity is considered a risk factor for insulin resistance and is not included in diagnosis

    • Europid (Caucasians) – WC >37 in (94 cm) for men; WC >31 in (80 cm) for women
    • Africans – Europid cutoffs should be used in the absence of more specific data
    • Indian Asians – WC >35 in (90 cm) for men; WC >31 in (80 cm) for women

    Dyslipidemia – triglycerides

    >150 mg/dL

    >150 mg/dL

    >150 mg/dL

    >150 mg/dL or patient taking specific treatment for hypertriglyceridemia

    Dyslipidemia – HDL-C

    • Men – <35 mg/dL
    • Women – <40 mg/dL
    • Men – <40 mg/dL
    • Women – <50 mg/dL
    • Men – <40 mg/dL
    • Women – <50 mg/dL
    • Men – <40 mg/dL
    • Women – <50 mg/dL

    Hypertension

    >140/90 mmHg or documented use of antihypertensive therapy

    >130/85 mmHg or documented use of antihypertensive therapy

    >130/85 mmHg

    >130/85 mmHg or documented use of antihypertensive therapy

    Hyperglycemia

    Either impaired glucose tolerance, impaired fasting glucose, insulin resistance, or diabetes 

    Fasting plasma glucose >100 mg/dL

    Fasting plasma glucose 100-125 mg/dL or 2-hour post-glucose challenge (75g) 140-200 mg/dL

    Fasting plasma glucose >100 mg/dL or previously diagnosed type 2 diabetes

    Microalbuminuria

    Urinary albumin-to-creatinine ratio >30 mg/g, or albumin excretion >20 μg/min

    Not included

    Not included

    Not included

    Abbreviations: AACE = American Association of Clinical Endocrinologists; BMI = body mass index; BP = blood pressure; EGIR = European Group for the Study of Insulin Resistance; HDL-C = high-density lipoprotein cholesterol; IDF = International Diabetes Federation; IRS = insulin resistance syndrome; MS = metabolic syndrome; NCEP ATP III = National Cholesterol Education Program Adult Treatment Panel III; OGT = oral glucose tolerance; TG = triglycerides; WC = waist circumference; WHO = World Health Organization

Laboratory Testing

  • Lipid panel
  • Glucose measurement
    • Fasting glucose
    • Glucose tolerance – may also use if criteria not met but suspicion for diabetes mellitus is moderate to high
    • Hemoglobin A1c (HbA1c) – not currently incorporated into diagnostic criteria

Monitoring

Clinical Background

Metabolic syndrome is a cluster of cardiovascular factors that are associated with an increased risk for developing cardiovascular disease (CVD) and diabetes mellitus (DM).

Epidemiology

  • Prevalence – ~23% in U.S. (Hiram, 2013, using NHANES data, 2009-2010)
  • Age
    • Incidence increases with age
      • Found in ≥50% of patients >60 years
    • Becoming more common during childhood (see Pediatrics tab)
  • Sex – M:F, equal

Risk Factors

Pathophysiology

  • Insulin resistance thought to represent most of the underlying pathophysiology
    • Obesity and physical inactivity lead to insulin resistance
  • Proinflammatory and prothrombotic state with glucotoxicity and lipotoxicity contributes to metabolic and vascular abnormalities

Clinical Presentation

  • Central obesity (apple shape)
  • DM – typically type 2
  • Hyperlipidemia
  • Hypertension
  • Complications

Pediatrics

Clinical Background

Epidemiology

  • Prevalence – 6.4% (Cook, 2007, using NHANES data, 1999-2000)
  • Sex – M>F
  • Age – usually ≥12 years

Definition of Obesity in Children

  • Obesity in children (2-19 years) – called childhood overweight
  • BMI ≥95 percentile for children of same age and sex (CDC, 2011 and AAP, 2003)

Clinical Presentation

  • Hypertension
  • Obesity
    • Severe defined as waist circumference >90%
  • Dyslipidemia
    • Glucose abnormalities
    • Usually DM type 2
    • May be impaired glucose tolerance
  • Complications

    Diagnosis

    Indications for Testing

    • Suspicion based on criteria for diagnosis – hypertension, dyslipidemia, glucose intolerance, moderate to severe obesity

    Criteria for Diagnosis

    • No consensus for pediatric criteria
      • Use adult diagnostic elements with pediatric cutoffs (see Diagnosis section for National Cholesterol Education Program Adult Treatment Panel III criteria)
    • Must meet 3 of 4 criteria
      • Triglyceride concentration – >110 mg/dL
      • HDL-C – ≤40 mg/dL
      • Blood pressure – 90% for age, gender, height
      • Fasting blood glucose – ≥100 mg/dL (ADA guidelines, 2014)

    Laboratory Testing

    • Lipid panel
    • Fasting glucose

Indications for Laboratory Testing

  • Tests generally appear in the order most useful for common clinical situations
  • Click on number for test-specific information in the ARUP Laboratory Test Directory
Test Name and Number Recommended Use Limitations Follow Up
Lipid Panel 0020421
Method: Quantitative Enzymatic

Use to assess cardiovascular disease risk and guide therapy

Panel includes cholesterol, serum or plasma; triglycerides, serum or plasma; LDL cholesterol, calculated; HDL cholesterol; very low density lipoprotein, calc; non-HDL cholesterol; appearance chemistry

   
Glucose, Plasma or Serum 0020024
Method: Quantitative Enzymatic

Use to diagnose and manage diabetes mellitus and other carbohydrate metabolism disorders

   
Glucose Tolerance Test 0020542
Method: Quantitative Enzymatic

Use to diagnose gestational diabetes mellitus, diabetes mellitus, or impaired glucose tolerance

   
Additional Tests Available
 
Click the plus sign to expand the table of additional tests.
Test Name and NumberComments
Lipid Panel, Extended 0020468
Method: Quantitative Spectrophotometry/Quantitative Enzymatic

Use to assess cardiovascular disease risk and guide therapy

Panel includes cholesterol, serum or plasma; triglycerides, serum or plasma; HDL cholesterol; LDL cholesterol, direct; VLDL, calculated; non-HDL cholesterol; appearance chemistry

Hemoglobin A1c 0070426
Method: Quantitative High Performance Liquid Chromatography/Boronate Affinity

Use to diagnose and monitor diabetes mellitus

Monitor prediabetes