Metabolic Syndrome


The metabolic syndrome has become increasingly common in the United States. It’s estimated that over 50 million Americans have it.

The metabolic syndrome is characterized by a group of metabolic risk factors:

  • Abdominal obesity
  • Atherogenic dyslipidemia (high triglycerides, low HDL cholesterol and high LDL cholesterol)
  • Elevated blood pressure
  • Insulin resistance or glucose intolerance
  • Prothrombotic state (e.g., high fibrinogen or plasminogen activator inhibitor-1)
  • Proinflammatory state (e.g., elevated C-reactive protein)

A number of markers of systemic inflammation, including C-reactive protein, are often increased, as are fibrinogen, interleukin 6 (IL-6), Tumor necrosis factor-alpha (TN Fa) and others. Commonly, upon expansion of the adipose mass it becomes gradually inflamed and hypoxic. The excess of fatty acids, in combination with local hypoxia, results in the induction of mitochondrial damage in adipocytes. The adipocytes of the visceral fat increase plasma levels of TNFa locally and alter levels of a number of other substances (e.g., adiponectin, resistin, PAI-1). TNFa has been shown not only to cause the production of inflammatory cytokines, but possibly to trigger cell signalling by interaction with a TNFa receptor that may lead to insulin resistance. Most people with insulin resistance have abdominal obesity.

The dominant underlying risk factors for this syndrome appear to be abdominal obesity and insulin resistance. Some people are genetically predisposed to insulin resistance. Acquired factors, such as excess body fat and physical inactivity, can elicit insulin resistance and the metabolic syndrome. Insulin resistance is most likely a consequence of defects in insulin signaling pathways that regulate translocation of GLUT -containing vesicles and docking of vesicles to the plasma membrane. Other conditions associated with the syndrome include physical inactivity, aging, hormonal imbalance and genetic predisposition.

National Cholesterol Education Program (NCEP) Criteria:
Must have at least 3 of the followinq 5 criteria:
1. Abdominal obesity with a waist circumference

a. Men: > 40 inches (in some men: 37-39 may be a risk factor)
b. Women: > 35 inches

2. Fasting TG level > 149 mg/dL

(this is the strongest independent predictor of risk for MI and stroke of the 5)

3. HDL-C level

a. Men: < 40 mg/dL
b. Women: < 50 mg/dL

4. Fasting blood sugar >99 mg/dL (or fasting insulin> 10 uU/ml)
5. Blood pressure

a. Systolic > 129 mm Hg, OR
b. Diastolic > 84 mm Hg, or requiring antihypertensive therapy

Causes of Metabolic Syndrome 

  • Lifestyle issues
    • Diet
    • Inactivity
    • Poor sleep
    • High chronic stress
  • Oxidative stress
  • Visceral fat
  • Pro-inflammatory state
  • Hormonal
    • Low vitamin D
    • Low testosterone
    • Hypothyroid
    • Low adiponectin
    • High resistin
    • Leptin dysregulation • Genetics

Metabolic Syndrome Features 

  • Small, dense LDL particles
  • Insulin resistance
  • Obesity
  • Inadequate exercise

Prevalence of Metabolic Syndrome

BMI Men Women
Normal <25 4.6% 6.2%
Overweight 25-29.9 22.4% 28.1%
Obese > 29.9 59.6% 50.0%
  • Overall incidence
    • Adults 22-25%
    • Older adults 42%
    • Affects up to 70 million Americans
  • High internal fat is the strongest predictor of metabolic syndrome, though researchers find that signs of inflammation in the blood and the amount of lean muscle in the body are also factors.

Metabolic Syndrome Increases Disease Risk 

People with the metabolic syndrome are at increased risk of coronary heart disease, stroke, peripheral vascular disease, and type-2 diabetes, etc.

  • Metabolic syndrome: MI 41.5% • Stroke 43.5%
  • Abdominal obesity: MI 51.8% • Stroke 54.9%
  • High Triglycerides: MI 43.2% • Stroke 61.9%
  • Low HDL: MI 45.0% • Stroke 52.1%
  • Hypertension: MI 48.2% • Stroke 57.0%
  • Insulin Resistance: MI 25.6% • Stroke 19.0%
  • Men with 4-5 criteria have 4 times the risk of CHD and 25 times the risk of diabetes
  • 2.6 times for Chronic Kidney Disease
  • 2 times for development of microalbuminuria
  • 2 times for stroke and MI
  • Risk increases for
    • Alzheimer’s disease
    • Blood clotting
    • Immune impairment
    • Polycystic ovaries
    • Infertility
    • Irregular menstruation
    • Acne and other skin disorders
    • Unwanted body hair in young females
    • Waning sexual function
    • Fatty liver
    • Liver disease
    • Cancer