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 2007) – 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, 2012)
  • 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 to 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 specific treatment

    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 required 

    Fasting plasma glucose >100 mg/dL

    Fasting plasma glucose 100-125 mg/dL or 2-hour post-glucose challenge (75g) of 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 in criteria

    Not in criteria

    Not in criteria

    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
  • Fasting glucose
  • Glucose tolerance – may also use if criteria not met but suspicion for DM 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

  • Incidence – 40-50 million in U.S.
  • 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

Treatment

  • Diet and exercise with weight loss
  • Blood pressure reduction measures
    • May require antihypertensives and lipid-lowering agents

Pediatrics

Clinical Background

Epidemiology

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

Definition

  • 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

Diagnosis

Indications for Testing

  • Suspicion based on criteria for diagnosis – hypertension, dyslipidemia, glucose intolerance, 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, 2012)

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

Determine cardiovascular risk; also used as a criterion for cardiometabolic syndrome

   
Glucose, Plasma or Serum 0020024
Method: Quantitative Enzymatic

Determine diabetic risk; also used as a criterion for cardiometabolic syndrome

   
Glucose Tolerance Test 0020542
Method: Quantitative Enzymatic

Determine diabetic risk; also used as a criterion for cardiometabolic syndrome

Components include fasting glucose and 2-hour glucose

   
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

Determine cardiovascular risk; also used as a criterion for cardiometabolic syndrome

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

Diagnose or monitor DM (in adults)

Diagnosis should be confirmed with a repeated test