Treating Cholesterol in Patients with Mild Kidney Disease

Summaries for Patients are a service provided by Annals to help patients better understand the complicated and often mystifying language of modern medicine.

Summaries for Patients are presented for informational purposes only. These summaries are not a substitute for advice from your own medical provider. If you have questions about this material, or need medical advice about your own health or situation, please contact your physician. The summaries may be reproduced for not-for-profit educational purposes only. Any other uses must be approved by the American College of Physicians-American Society of Internal Medicine.

The summary below is from the full report titled "Pravastatin for Secondary Prevention of Cardiovascular Events in Persons with Mild Chronic Renal Insufficiency." It is in the 21 January 2003 issue of Annals of Internal Medicine (volume 138, pages 98-104). The authors are M Tonelli, L Moyé, FM Sacks, B Kiberd, and G Curhan, for the Cholesterol and Recurrent Events (CARE) Trial Investigators.

What is the problem and what is known about it so far?

Renal insufficiency is a loss of the normal function of both kidneys and is common in the general population, affecting approximately 6 million North Americans. People with chronic renal insufficiency have high risks for coronary heart disease. They often have other medical conditions, including high blood pressure, diabetes, or high cholesterol levels, which also increase risks for coronary heart disease.

One way that doctors try to lower these risks is by treating high cholesterol. They often use drugs known as statins to lower cholesterol. However, studies show that doctors don't commonly use statins in people who have heart disease and chronic renal insufficiency. They may think that statins don't work as well or that statins have more side effects in people with chronic renal insufficiency.

Why did the researchers do this particular study?

To see whether a statin (pravastatin) is effective and safe for patients with coronary heart disease and mild to moderate chronic renal insufficiency.

Who was studied?

1711 men and women with a previous heart attack, elevated cholesterol level, and mild to moderate chronic renal insufficiency.

How was the study done?

The researchers studied a subset of patients who had participated in a large randomized, controlled trial. In the trial, patients with a previous heart attack and mildly elevated cholesterol levels were randomly assigned to take either pravastatin or a dummy pill (placebo). Neither the patients nor their doctors knew which drug the patients were given. Patients were followed for about 5 years. During that time, the researchers routinely checked for repeated heart attacks, deaths from coronary disease, and side effects. In this subset analysis, the researchers compared the frequency of heart attacks and deaths from coronary disease among the patients who had mild to moderate renal insufficiency.

What did the researchers find?

Patients assigned to pravastatin had fewer heart attacks and deaths from coronary disease (10.5%) than patients assigned to placebo (14.5%). Benefits of pravastatin treatment appeared similar regardless of renal insufficiency. Patients with renal insufficiency who were given pravastatin had few serious side effects. Also, patients given pravastatin and placebo had similar frequencies of side effects.

What were the limitations of the study?

The study included only patients with mild to moderate renal insufficiency. Statins may have different effects in patients with more severe renal insufficiency.

What are the implications of the study?

Pravastatin is an effective, safe therapy for patients with previous heart attack, elevated cholesterol level, and mild to moderate renal insufficiency. Doctors should use, not avoid, statins in patients with heart disease, elevated cholesterol level, and mild to moderate renal insufficiency.