Cholesterol Levels Count in Kidney Disease Patients: Study
Posted Sep 24 2010 10:00am
When malnutrition, inflammation are not present, high levels raise heart disease risk, research shows.
FRIDAY, Sept. 24 (HealthDay News) -- Malnutrition and inflammation may be important risk factors for cardiovascular disease in patients with chronic kidney disease (CKD) and need to be considered when doctors are assessing patients' cholesterol levels, a new study suggests.
Cardiovascular disease is a common condition and cause of death in CKD patients. In the general population, high cholesterol levels increase the risk of cardiovascular disease and death, but this association isn't so clear in CKD patients, according to background information in an American Society of Nephrology news release about the study.
Previous research has shown that CKD patients with high cholesterol levels are less likely to die than those with lower cholesterol levels. This may be because high cholesterol levels in these patients can indicate lower levels of malnutrition and inflammation, two related complications of kidney disease.
The new study examined 990 black Americans with chronic kidney disease who were not yet on dialysis. Malnutrition and/or inflammation was present in 31 percent of the patients.
Over 12 years of follow-up, 20 percent of the patients experienced a new cardiovascular disease "event" such as heart attack, stroke, congestive heart failure, or death from heart disease. The rates were similar among patients with and without malnutrition and/or inflammation, 19 percent and 21 percent, respectively.
Among patients with malnutrition and/or inflammation, high cholesterol levels were not associated with cardiovascular disease events. But among patients without malnutrition and/or inflammation, the risk of a new cardiovascular disease event increased as cholesterol levels rose, the investigators found. The risk was 2.18 times greater for those with cholesterol levels of 240 mg/dL or higher and 1.19 times greater for those with cholesterol levels between 200 and 239 mg/dL, compared to those with cholesterol levels less than 200 mg/dL.
"In CKD patients, the inconsistent and often inverse relationship of cholesterol level with cardiovascular disease and overall mortality may be explained by the presence of malnutrition and/or inflammation," study author Dr. Gabriel Contreras, of the University of Miami Miller School of Medicine, said in the news release.
This means physicians should investigate the causes of low and high cholesterol levels in patients with chronic kidney disease, the study authors noted.
"Whereas traditional risk factors such as elevated blood cholesterol levels remain important, they appear to compete and interact with non-traditional risk factors such as malnutrition and inflammation. Doctors caring for CKD patients should take into account the presence of malnutrition and inflammation as they interpret blood cholesterol levels," Contreras concluded.
The study findings were released online Sept. 23 in advance of publication in an upcoming print issue of the Journal of the American Society of Nephrology.