06.04a

Written By Joan

Metabolic syndrome

Definition

  • Aka Syndrome X or insulin resistance syndrome

  • Refers to cluster of abnormalities including insulin resistance, impaired glucose control, abdominal obesity, deranged cholesterol levels, and hypertension

    • No universally agreed definition; diagnostic criteria depends on guideline used

Risk factors: obesity, physical inactivity, high-saturated fat & carbohydrate diet, alcohol excess, smoking, antipsychotic use, increasing age, FHx of metabolic syndrome

Aetiology: interplay of lifestyle, environmental and genetic factors converging in cascade of events that manifest metabolic syndrome

Pathophysiology:

  • Main defect is likely to do with insulin resistance resulting impaired glucose metabolism.

  • Insulin resistance also results in reduced ability to suppress lipolysis → higher plasma concentration of free fatty acids → several mechanisms by which cholesterol and triglyceride levels become deranged

  • Insulin itself also has effects on blood pressure (including influencing sodium reabsorption and activation of the sympathetic nervous system) → hypertension

S/smx

  • Metabolic syndrome itself is ‘asymptomatic’ but is a major risk factor for developing complications including MI, MASLD, etc

  • Common co-morbidities such as PCOS will be symptomatic and should prompt thought into whether a patient has metabolic syndrome

Ix / Diagnostic criteria

  • According to NCEP ATP III (most commonly used) – at least 3 out of following 5 criteria

    • Abdominal obesity: waist circumference ≥102cm in males, ≥88cm in females

    • Hypertriglyceridemia: ≥1.7mmol/L (≥150 mg/dl)

    • Low HDL-C: <1.04 mmol/dL (40 mg/dL) in males
      <1.30 mmol/dL (< 50 mg/dL) in females

    • Hypertension: >130/85 mmHg

    • High fasting glucose: >6.1mmol/L (>110 mg/dl)

  • Different guidelines have slightly different cut-offs and additional criteria, but are generally quite similar

Mx

  • Lifestyle change & weight loss

    • Diet: more fruits, vegetables, nuts, whole grains, olive oil + low-fat diet.

    • Exercise

  • Pharmacological interventions: Weight loss medications (eg semaglutide)? Bariatric surgery? Metformin? Statin therapy (if ASCVD risk is high)? Antihypertensives?

Prognosis

  • If lifestyle changes adopted, progression to cardiovascular disease and T2DM can be prevented.

Note from Joan: have chosen not to incorporate this into the actual PDF notes at this point. 11/08/2025.

Joan
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