Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (67 page)

   Decreased acid lipase in lymphocytes or fibroblasts

   Increased serum TG, LDL-C, and cholesterol esters

METABOLIC SYNDROME

   Metabolic syndrome is a condition of interrelated risk factors of metabolic origin, chief of which is insulin resistance, dyslipidemia, and hypertension that confer elevated cardiovascular risk.

   The most common definition of metabolic syndrome requires abdominal obesity (waist circumference >88 cm in women and >102 cm in men), elevated blood pressure (SBP >130 mm Hg, DBP >85 mm Hg or antihypertensive medication), Low HDL-C (<40 mg/dL men, <50 mg/dL women), elevated fasting triglycerides of >150 mg/dL or nonfasting >400 mg/dL and impaired fasting glucose of 100 mg/dL or greater.

   Prevalence is 33.7% in men and 35.4% in women from data from 1999 to 2002.

   Metabolic syndrome may contribute up to 12–17% of all cardiovascular disease.

   Direct measurement of LDL-C is recommended for the diagnosis of metabolic syndrome.

   At present, CRP is not part of the definition of metabolic syndrome but does appear to add predictive risk of coronary events and may impact treatment decisions. Increased levels of fibrinogen, plasminogen activator inhibitor-1 and other coagulant factors are seen in patients with metabolic syndrome, but are not required for diagnosis.

ATHEROGENIC DYSLIPIDEMIA

   TG >150 mg/dL, HDL-C <40 mg/dL in men and <50 mg/dL in women, with small dense LDL particles.

   Abnormalities in fibrinolysis and coagulation.

   Exclusion of other causes of dyslipidemia (e.g., cholestasis, hypothyroidism, chronic renal failure, nephrotic syndrome).

HYPERALPHALIPOPROTEINEMIA (HDL-C EXCESS)

   This condition is inherited as a simple autosomal dominant trait in families with longevity, or it may be caused by alcoholism, extensive exposure to chlorinated hydrocarbon pesticides, or exogenous estrogen supplementation.