OVERVIEW
This is a common disorder, often familial, characterized by elevated plasma triglycerides, predominantly very low density (pre-beta) lipoproteins, and a tendency toward early onset of atherosclerosis. Endogenous triglyceride levels are usually classified as type IV hyperlipoproteinemia, which is common in men in the United States.
Etiology
The disease is associated with lifestyle, diet, and genetics. It runs in families and can be secondary to diabetes, hypothyroidism, nephrotic syndrome, and excessive alcohol consumption.
Symptoms
The main manifestation is a rash of xanthomas, occurring suddenly on the trunk, buttocks, arm extensions, or thighs. Severe cases may occur anywhere on the skin, with nodular xanthomas, tendon xanthomas, and maculomas being atypical. 40% of cases have hyperuricemia, and 90% of patients have occult diabetes mellitus.
Examination
Common investigations for hyperlipoproteinemia type IV include routine blood tests and serologic tests.
Diagnosis
This form of lipemia is often associated with abnormal glucose tolerance (insulin antagonism), obesity, and can be exacerbated by controlling dietary fats and relatively increasing carbohydrates (with normal calorie intake). Plasma is cloudy and triglyceride levels are elevated. normal to mildly elevated TC (often secondary to stress, after alcohol use and dietary intolerance) can be associated with hyperuricemia. Low HDL levels are due to elevated triglycerides and may return to normal when triglycerides are reduced to normal.
Treatment
Weight loss and restriction of alcohol intake are the most effective treatments and often reduce triglycerides to normal levels. It is important to maintain an appropriate body weight and to control carbohydrates and alcohol in the diet. Niacin or gemfibrate taken orally may further reduce hyperlipidemia in patients who have failed to control it through diet.
Prognosis.
Earlier onset of coronary and peripheral vascular changes.