NEWSLETTER

DIAGNOSTIC CRITERIA OF THE METABOLIC SYNDROME- A brief review

Dr. Khalid Imam, Consultant Endocrinologist - Liaquat National Hospital

The Metabolic syndrome refers to a clustering of specific cardiovascular disease risk factors whose underlying pathophysiology is thought to be related to insulin resistance. Clinical studies have shown that the term metabolic syndrome is imprecisely defined and too much critically important information is missing to warrant its designation as a "syndrome."

Potential advantages of the Metabolic Syndrome Criteria:

  1. It is an operational definition of the ‘cardiometabolic risk factors.’
  2. Encourages to look for the other risk factors.
  3. Encourages behavior therapy rather than treating individual risk factors.
  4. Better predictor of diabetes than cardiovascular disease.

Potential disadvantages of the Metabolic Syndrome Criteria:

  1. Risk factors of the metabolic syndrome differ in their ability to predict diabetes and cardiovascular disease.
  2. Its still unclear whether the metabolic syndrome predict cardiovascular disease independent of its components.
  3. Insulin resistance as the unifying cause is uncertain.
  4. Cut off values for the risk factors are different in different countries.
  5. No clear basis for including or excluding other cardiovascular risk factors.

Diagnostic criteria used in clinical practice:

WHO criteria:
• Dysglycemia ( DM, IFG, IGT, IR)
Plus 2 of the following:
• BMI >= 30 (> 26 for Asians)
• Dyslipidemia ( TG >=150 mg/dl) / Low HDL: (Male <= 35 mg/dl, Female >= 40 mg/dl)
• B.P 140/90 mmHg
• Microalbuminuria ( >20 mcg/min)

ATP III Criteria of the Metabolic Syndrome:

  1. Waist: Male >90 cm, Female > 80 cm (Caucasians M > 102 cm, F > 88 cm)
  2. TG >= 150 mg/dl
  3. HDL: M >= 40 mg/dl, F >= 50 mg/dl
  4. B.P >= 130/85 mmHg or known hypertensive
  5. FPG >= 110 mg/dl or diabetes

3 or more are required for the diagnosis

IDF Criteria of the Metabolic Syndrome:

Increase Waist: Male >= 90 cm, Female > 80 cm; (Caucasians M > 102 cm, F > 88 cm)

Plus any 2 of the following:

• TG >= 150 mg/dl
• HDL: M <= 40 mg/dl, F <= 50 mg/dl
• B.P >= 130/85 mmHg
• FPG >= 100 mg/dl or known diabetic

Similar to ATP III except Waist circumference is an essential element and cut off for FPG is 100 mg /dl.

AHA Criteria of the Metabolic Syndrome

  1. Waist: Male >90 cm, Female > 80 cm; (Caucasians M > 102 cm, F > 88 cm)
  2. TG >= 150 mg/dl
  3. HDL: M <= 40 mg/dl, F <= 50 mg/dl
  4. B.P >= 130/85 mmHg or known hypertensive
  5. FPG >= 110 mg/dl or known diabetic

3 or more are required for the diagnosis. Similar to ATP III except cut off for FPG is 100
mg/dl.

Abdominal obesity and waise circumference thresholds

  Men Women
South Asians >= 90 cm (35.4 in) >= 80 cm (31.5 in)
Chinese >= 90 cm (35.4 in) >= 80 cm (31.5 in)
Japanese >= 85 cm (33.5 in) >= 90 cm (35.4 in)
Caucasians >=102 cm (40 in) >= 88 cm (35 in)

What is needed?

  • A critical analysis is required to define the syndrome.
  • An evidence–based approach is needed to assess the rationale and value of adding other cardiovascular risk factors like CRP, family history etc.
  • More research is required to identify the underlying cause(s) of the metabolic syndrome.

Conclusion:

We, as clinicians, should evaluate and treat all cardiovascular risk factors without regard to whether a patient meets the criteria for diagnosis of the metabolic syndrome.

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