Hypertriglyceridemia

In medicine, hypertriglyceridemia (or "Hypertriglyceridaemia") denotes high (hyper-) blood levels (-emia) of triglycerides, the most abundant fatty molecule in most organisms. It has been associated with atherosclerosis, even in the absence of hypercholesterolemia (high cholesterol levels). It can also lead to pancreatitis in excessive concentrations. Very high triglyceride levels may also interfere with blood tests; hyponatremia may be reported spuriously (pseudohyponatremia).

A related term is "hyperglyceridemia" or "hyperglyceridaemia", which refers to a high level of all glycerides, including monoglycerides, diglycerides and triglycerides.

Signs and symptoms

Modestly elevated triglyceride levels do not lead to any physical symptoms. Higher levels are associated with lipemia retinalis (white appearance of the retina), eruptive xanthomas (small lumps in the skin, sometimes itchy).

Causes

• Idiopathic (constitutional)
• Obesity
• High carbohydrate diet
• Diabetes mellitus and insulin resistance - it is one of the defined components of metabolic syndrome (along with central obesity, hypertension, and hyperglycemia)
• Excess alcohol intake
• Nephrotic syndrome
• Genetic predisposition
• Certain medications (e.g., isotretinoin)
• Hypothyroidism (underactive thyroid)

Treatment

Treatment of hypertriglyceridemia is by restriction of carbohydrates and fat in the diet, as well as with niacin, fibrates and statins (three classes of drugs). Increased fish oil intake may substantially lower an individual's triglycerides.^[1][2][3]

Clinical practice guidelines by the National Cholesterol Education Program (NCEP) suggests that pharmacotherapy be considered with a triglycerides level over 200 mg/dL.^[4] The guidelines state "the sum of LDL + VLDL cholesterol (termed non-HDL cholesterol [total cholesterol - HDL cholesterol]) as a secondary target of therapy in persons with high triglycerides (200 mg/dL). The goal for non-HDL cholesterol in persons with high serum triglycerides can be set at 30 mg/dL higher than that for LDL cholesterol (Table 9) on the premise that a VLDL cholesterol level 30 mg/dL is normal."^[4]

Non–HDL cholesterol contains the highly atherogenic, small, dense lipoproteins that are associated with a high incidence of cardiovascular disease (CVD). Studies subsequent to the NCEP report have shown that the non–HDL cholesterol level predicts CVD in people who have diabetes. It may be superior to LDL cholesterol in this regard, and should be used as the primary lipid target in persons with diabetes. ^[5]

Primary prevention

Omega-3 fatty acid supplementation in the form of fish oil has been found to be effective in decreasing levels of triglycerides and thus all cardiovascular events by 19% to 45%.^[6]

Gemfibrozil twice daily in asymptomatic men ages 40–55 without heart disease was also found to be effective at reducing cardiac endpoints at 5 years (4.14% to 2.73%). This means that 54 people must take the treatment for five years to prevent one cardiac event (number needed to treat of 54).^[7]

Secondary prevention

A randomized controlled trial of men with known heart disease and HDL cholesterol of 40 mg/dl or less , 600 mg of gemfibrozil twice daily reduced cardiac endpoints (non-fatal myocardial infarction or death from coronary causes) at 5 years from 21.7% to 17.3%. This means that 23 patients must be treated for five years to prevent one cardiac event (number needed to treat is 23).^[8]

References