Lipids (fats), together with proteins and carbohydrates, are the main components of living cells. Cholesterol and triglycerides are lipids that are stored in the body and serve as a source of energy in addition to their role in cell structure. Desirable levels of blood fats are:

Total cholesterol

Below 200 mg/dL

HDL cholesterol

Men: above 40 mg/dL

Women: above 50 mg/dL

LDL cholesterol

Below 100 mg/dL

Below 70 mg/dL for people with diabetes or heart disease

Triglycerides

Below 150 mg/dL

When lipid levels in the bloodstream are too high or low, this condition is called dyslipidemia. The most common types of dyslipidemia are:

High levels of low-density lipoprotein (LDL or “bad”) cholesterol

Low levels of high-density lipoprotein (HDL or “good”) cholesterol

High levels of triglycerides

When LDL cholesterol levels are high, fatty deposits (called plaques) can build up in the arteries, the blood vessels that carry blood from the heart throughout the body. Over time, plaques narrow the arteries, producing atherosclerosis (hardening of the arteries). This can cause heart disease, heart attack, peripheral artery disease (reduced blood flow in the limbs, usually the legs), or stroke. Low levels of HDL and high levels of triglycerides can also increase fat build-up in the arteries. High levels of HDL cholesterol, however, protect the heart by helping to remove the build-up of LDL from the arteries.

Endocrine causes of dyslipidemia

The most common lipid disorder is hyperlipidemia, high levels of blood fat. While many of its possible causes are nonendocrine, hyperlipidemia can also be related to a hormonal disease such as diabetes, hypothyroidism (low levels of thyroid hormone), polycystic ovary syndrome (PCOS), metabolic syndrome, and Cushing syndrome. Central obesity (excess fat around the waist) or insulin resistance (a condition in which the body doesn’t use insulin properly), or both—each of which are risk factors for dyslipidemia—are commonly found in patients with these endocrine disorders.

© 2012 The Hormone Foundation. All rights reserved.

Hyperlipidemia