"This study is the first large-scale, comparative evaluation of cholesterol treatment and control in four major U.S. ethnic groups," said David C. Goff, M.D., Ph.D., the report's first author and a professor of public health science and internal medicine at the Wake Forest University School of Medicine in Winston-Salem, N.C.
Researchers examined the cholesterol levels of 6,704 of the 6,814 participants in the Multi-Ethnic Study of Atherosclerosis (MESA), funded by the National Heart, Lung, and Blood Institute. This ongoing study seeks to discover if any differences exist between ethnic groups in the development of heart disease.
The study measured prevalence and control of high cholesterol among the four ethnic groups, and found striking differences in treatments.
- Among persons with high cholesterol, Hispanics were 36 percent less likely than non-Hispanic whites to have properly controlled cholesterol, and non-Hispanic blacks were 28 percent less likely. No difference was seen between Chinese Americans and non-Hispanic whites.
- Compared to non-Hispanic whites, Chinese Americans were 21 percent less likely to meet the criterion for drug therapy. Hispanics and non-Hispanic blacks were equally likely as non Hispanics whites to qualify for drug therapy.
- At least 22.3 percent of all participants had cholesterol levels for which the guidelines recommend medications.
- Among the 1,494 individuals meeting the criterion for drug therapy, only 39 percent received treatment, and treatment was often insufficient to meet recommended goals. Treatment began in August 2002 and continued till July 2002.
- Men were 28 percent more likely than women to qualify for drug therapy, but 22 percent less likely to receive treatment.
- Among those who met the recommendation for drug therapy, men were 30 percent less likely than women to have their cholesterol under control.
- Only 330 (55.9 percent) of the 590 individuals appropriately treated for high cholesterol had their cholesterol under control.
Almost half did not reach their goal. Thus, only 22 percent of the 1,494 patients who qualified for medications had their cholesterol under control.
Among all ethnic groups studied, only one in five Americans who qualify to take drugs to lower their high cholesterol levels have their LDL cholesterol under control.
"We were interested in assessing how often people are getting their cholesterol treated when it is high enough to warrant treatment," Goff said. "Treating high cholesterol can reduce the risk of heart disease by about 30 percent."
MESA researchers enrolled study participants in 2001 and 2002 in six metropolitan areas: Baltimore, Chicago, Los Angeles, Minneapolis-St. Paul, New York City and Winston-Salem, N.C. The study was designed to have a diverse ethnic mix.
Participants were age 45 to 84 at their time of entry and had no symptoms of cardiovascular disease. Each completed a health survey, underwent a physical exam and laboratory tests, and some had imaging studies. In assessing enrollees' cholesterol levels and need for cholesterol-lowering treatment, the researchers used 2001 treatment guidelines commonly known as ATPIII. The Adult Treatment Panel of the National Heart, Lung, and Blood Institute's National Cholesterol Education Program formulated the ATPIII guidelines.
ATPIII recommends treatment based on a person's blood level of LDL cholesterol. The threshold level for LDL treatment, either with lifestyle changes or drugs, depends on whether a person has heart disease, diabetes or other risk factors, Goff said.
For some people, the recommended level is less than 100 milligrams per deciliter (mg/dL); for others it's less than 130 mg/dL; and for still others it's less than 160 mg/dL. In recommendations published in 2004, a very-high risk group was identified with a goal of less than 70 mg/dL.
"The implications of this study are that high cholesterol is very common, treatment is far from ideal, and disparities in control persist," Goff said. "We have very effective treatments for high blood cholesterol, but for people to benefit, they must have their cholesterol measured, have treatment prescribed by physicians, and take the medication as advised."
The new findings confirm data from the fourth National Health and Nutritional Examination Survey (NHANES IV) assessing total cholesterol treatment and control among blacks, whites, and Mexican Americans. It showed lower rates of control among both blacks and Mexican Americans than whites, but did not assess treatment in relation to the ATPIII recommendations.
"The public needs to become more aware of the importance of getting their cholesterol checked and being treated if it is high, because informed patients can make sure they get good care," Goff said. "Physicians and other healthcare professionals need to work together to improve the quality of care that is delivered to patients with high cholesterol."
Co-authors are Alain G. Bertoni, M.D.; Denise E. Bonds, M.D.; Holly Kramer, M.D.; Michael Y. Tsai, Ph.D.; Roger Blumenthal, M.D., and Bruce M. Psaty, M.D., Ph.D.
Statements and conclusions of study authors that are published in the American Heart Association scientific journals are solely those of the study authors and do not necessarily reflect association policy or position. The American Heart Association makes no representation or warranty as to their accuracy or reliability.
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(Note: This news release contains updated data from the abstract)