Triglycerides are a type of fat also known as VLDL (very low density lipoproteins). They are formed when one of a group of fatty acids (oleic acid, stearic acid and palmitic acid) combines with glycerol. Triglycerides are found in most animal and vegetable fats and form an essential part of the human diet. Only when eaten in excess, or excessively concentrated in the bloodstream, do they become a problem. Oral contraceptives may also be responsible for raising the blood triglyceride level.
High levels of triglycerides in the blood (hypertriglyceridaemia) predisposes towards an increased risk of strokes and heart attacks, as the excess triglyceride is deposited along with cholesterol on the inside wall of arteries to cause hardening of the arteries (arteriosclerosis). The cholesterol levels are more important than those of triglyceride in this process.
The amount of triglyceride present in the blood can be readily measured in a pathology laboratory. For an accurate result, it is necessary for the patient to fast for twelve hours and avoid alcohol for three days before the test. A level below 2.3 mmol/L is considered normal.
Low levels of triglyceride occur in malnutrition, while high levels can be an inherited trait or may be associated with a wide range of conditions including obesity, the nephrotic syndrome (kidney disease), chronic kidney failure, diabetes mellitus, hypothyroidism (under active thyroid gland), Cushing syndrome, pancreatitis, hypopituitarism (under active pituitary gland under the brain), acromegaly (enlargement of bones), glycogen storage diseases, alcoholism, pregnancy and the use of drugs (eg. oral contraceptives, steroids).
Patients with excess blood triglyceride levels can usually be controlled by a diet that excludes most animal and vegetable fat (eg. fried food, dairy products, fatty meats). A low triglyceride diet would exclude all fried food, most dairy products and fatty meats (eg. sausages, lamb chops). With hereditary disease or severe cases, medication must be taken long term as well as the diet.