Failing Kidneys Get Boost from Statins
In heart patients, Lipitor led to renal function rebound
THURSDAY, July 1, 2004 (HealthDayNews) -- Statins have scored again: The cholesterol-lowering drugs not only reduce the risk of heart attack in patients with cardiovascular disease, they also appear to boost the health of their flagging kidneys, new research shows.
"Statin treatment not only prevents this deterioration, but it significantly improves renal function," said study author Dr. Vasilios Athyros, of the Aristotelian University in Thessaloniki, Greece. The findings appear in the July issue of the Journal of Clinical Pathology.
Since their introduction, statins such as Lipitor, Pravachol, and Crestor have revolutionized the care of people with heart disease. As patients continue to use the drugs, studies are suggesting they may also fight a host of other ailments, including cancer, rheumatoid arthritis, multiple sclerosis, and Alzheimer's disease.
In this latest study, Athyros and his colleagues tracked the kidney function of 1,600 Greek patients with heart disease and normal kidney function. The participants, all under the age of 75, were part of a study on the effectiveness of Lipitor in treating coronary disease.
Half of the group received Lipitor, the majority taking a 20-milligram dose of the drug per day. The other half of the group was placed on a low-fat diet and a regular exercise program. In this second group, 133 took some cholesterol-lowering drugs.
Kidney function deteriorates naturally with age, but this decline is more rapid in patients with heart disease. To see whether Lipitor was helping patients regain lost kidney function, Athyros periodically measured how well the kidneys cleared creatine, a waste product.
After three years of follow-up, the ability of patients not taking Lipitor to clear creatine from their kidneys fell by 5 percent.
On the other hand, patients on Lipitor displayed a 12 percent increase in creatine clearance -- a sign their kidneys were actually rebounding.
According to Athyros, these results are "probably related to an effect of statin treatment on blood flow of the kidney," with Lipitor increasing circulation as it lowers artery-clogging LDL, the "bad" cholesterol.
Besides improving kidney function, patients taking Lipitor in the Greek trial cut their risk of death from heart attack in half, compared to patients not receiving a statin. Their risk of death from all causes fell by 43 percent, the researchers report.
The exact link between heart disease and kidney function remains unclear, said Dr. Richard A. Stein, a spokesman for the American Heart Association and chief of medicine at Beth Israel Medical Center in New York City. However, within failing kidneys, a process called glomerulosclerosis acts very much like atherosclerosis (narrowing of arteries).
"LDL cholesterol could play a role in both processes," Stein theorized, so that drugs that lowered LDL in arteries might improve the health of kidneys, too.
Athyros said he hoped the study -- one of the largest of its kind -- would help change clinical practice, although most patients with coronary disease and kidney impairment are probably taking statins already.
Stein agreed, adding there's mounting evidence that cholesterol levels could go even lower. "LDL levels can get down very low," he said, even below the 130 milligrams per deciliter (mg/dL) treatment target currently advocated by the National Cholesterol Education Program's Adult Treatment Panel.
"That limit should probably be changed to a lower number," Stein said. "This committee meets every two to three years, and my suspicion is that they'll meet soon to adjust levels down."
Of course statins have their detractors. While no one disputes their LDL-busting power, one recent study linked use of the medications by pregnant women to a higher risk of birth defects. And the consumer safety group Public Citizen has urged a ban on Crestor, claiming it raises risks for kidney failure and a serious muscle condition called rhabdomyolysis.
But Stein remains optimistic about the overall promise of these drugs. "Of course, there's the idea that something that sounds too good to be true probably is. But on the other hand, statins could be the exception to that rule, and I think all of us are becoming convinced that many of these chronic disease processes are linked. Maybe one of these linkages could be LDL cholesterol -- acting when it's oxidized to cascade a series of events in different organs that present in different manners," he said.
"It's an intriguing idea," Stein added. "It's sort of a detective novel where we are now at the last third of the book and everything that's been happening is finally beginning to make sense."
For more on statins and other cholesterol-lowering drugs, visit the American Heart Association.