High density lipoprotein or HDL is the protective form of cholesterol that collects damaging fats throughout the body and transports them to the arteries for disposal. Women are advised to target a level of HDL above 50mg per deciliter and men above 40mg per deciliter, according to the National Institutes of Health Guidelines. Levels up to 82 mg per deciliter are considered to be beneficial. Above this an increased risk of arteriosclerosis occurs.
HALP Incidence
"Too much of HDL can lead to arteriosclerosis" as reported by Dr. Marquez-Contreras and his team from Barcelona, writing in the May 1993 issue of "Medical Clinician."
Hyperalphalipoproteinemia or HALP is defined as having an HDL level above 82 mg per deciliter. Approximately 8 percent of Americans over age 40 have HALP and, because there are no outward signs or symptoms of the disorder, these people are unaware of their increased risk of atherosclerosis, which is a particular form of arterial wall thickening.
The highest risk of HALP occurs in African-American women and Japanese-American men, according to National Institutes of Health statistics. In general, women are more likely to develop HALP than men and the prime time of life for HALP is in the 20s when the incidence approaches 14 percent of the general population, according to the researchers at the National Heart, Lung and Blood Institute.
Recognizing the risk factors and causes of HALP allows patients and their health care providers to take steps aimed at lowering HDL to normal levels before it causes arteriosclerosis. This is important because HALP begins, most commonly, before age 30, a decade before doctors routinely order lipid profiles, according Dr. Sich and Dr. Saidi, writing in the August 1998 issue of "Metabolism."
Primary HALP
When HALP occurs because of a genetic alteration it is a dominant trait. This means only one parent must carry the faulty gene for their children to have HALP. But, even if tested, the elevated HDL levels may not occur until the twenties.
CETP deficiency is one form of familial HALP with HDL levels seen above 100mg per deciliter in people having two copies of the abnormal gene. Arteriosclerosis from CETP deficiency is seen most commonly in Japanese American men. In the October 2003 issue of the "Journal of the American Medical Association" Dr. Barzilai notes that CETP deficiency in Japan is associated with extreme longevity. But when these men develop high triglycerides from eating a diet high in calories and carbohydrates the effect is reversed and atherosclerosis occurs.
Another group, from Columbia University published their findings in the June 1996 issue of "The Journal of Clinical Investigation" wrote that "Japanese American men with CETP deficiency can exhibit arteriosclerosis even at levels of HDL between 41 and 65 mg per deciliter." Their findings point to the need to tailor dietary and heath care decisions based on ethnicity. (see reference 4)
Secondary HALP
Low HDL is a known risk factor for cardiovascular disease and physicians are becoming more aggressive about treating this condition. In an effort to raise low HDL levels with medication it is not uncommon to have the therapeutic pendulum swing too high, resulting in HALP. Niacin, taken in dosages above 1g per day, fibrates and statins are the medications involved.
Long distance runners develop HALP to meet their muscles' needs, a condition that reverses when they stop training. This can be prevented by alternating days of running with days of other, less vigorous exercise.
People who drink three or more servings of alcohol daily can also have extremely high levels of HDL. Researchers at the National Institutes of Health have not found a specific time frame for the development of alcohol linked HALP but do note that teens and young adults who drink at this level should not wait until age 40 to begin having HDL levels tested annually.
References
- National Institutes of Health: ATP3 Cholesterol Guidelines
- "Medical Clinician"; Prevalence of hyperalphalipoproteinemia in the general population; E. Márquez Contreras, JJ Casado Martínez, JL Sánchez Ramos, et al.; May 8, 1993;
- "Metabolism".; Hyperalphalipoproteinemia: characterization of a cardioprotective profile associating increased high-density lipoprotein2 levels and decreased hepatic lipase activity; D.Sich, D, Y.Saïdi, F. Giral P, et al.;August 1998
- "Journal of Clinical Investigation"; Increased coronary heart disease in Japanese-American men with mutation in the cholesteryl ester transfer protein gene despite increased HDL levels.;S. Zhong, DS Sharp, et al, June 1996
- "Journal of the American Medical Association"; Unique lipoprotein phenotype and genotype associated with exceptional longevity; N. Barzilai, G Atzmon,et al.; October 2003
