A blanket term for abnormally high levels of lipids, such as cholesterol, in the bloodstream.
For years, it has been known that high levels of cholesterol in the blood can raise a person’s risk of developing heart disease. Cholesterol is transported in the bloodstream by carrier proteins known as lipoproteins. Low-density lipoproteins (LDL’s) tend to deposit cholesterol-laden “plaques” in artery walls, narrowing the opening through which blood flows and increasing the risk of heart disease. This is why LDL cholesterol has been dubbed the “bad” cholesterol. High-density lipoprotein (HDL) cholesterol is known as the “good” cholesterol because HDL carries cholesterol to the liver, where it is broken down and removed from the blood before it can wind up on artery walls.
High blood levels of triglycerides, the body’s storage form of fat and a primary source of energy, are also associated with a greater risk of heart disease, at least in some people. People with Type 2 diabetes are at especially high risk for hyperlipidemia, most commonly in the form of elevated triglyceride levels and decreased HDL levels.
In recognition of the link between blood cholesterol levels and heart disease, the National Cholesterol Education Program (NCEP), coordinated by the National Institutes of Health, set up target blood cholesterol levels aimed at minimizing people’s risk of heart disease. According to the NCEP, a total blood cholesterol level of less than 200 mg/dl is desirable, a level of 200 mg/dl to 239 mg/dl is considered borderline, and a level of 240 mg/dl or above is regarded as high. Similarly, an LDL cholesterol level of less than 100 is optimal, a level of 100 to 129 mg/dl is near optimal, a level of 130 to 159 is borderline, and a level of more than 160 mg/dl is considered high. An HDL cholesterol level below 40 mg/dl is also thought to place people at increased risk for heart disease.
The American Diabetes Association’s recommended cholesterol levels for adults with diabetes are slightly different: An LDL cholesterol level less than 100 mg/dl is considered optimal, as is an HDL cholesterol level higher than 40 mg/dl for men and higher than 50 mg/dl for women. As for triglycerides, a level of less than 150 mg/dl is considered optimal.
For people with moderately high lipid levels, lifestyle changes traditionally have been tried first: Losing excess weight, eating less saturated fat, exercising more, and stopping smoking can all improve lipid profiles by lowering LDL levels, raising HDL levels, or both. When lifestyle factors fail to control the problem, doctors can prescribe one of many cholesterol-lowering drugs.