New! Sign up for our free email newsletter.
Science News
from research organizations

Despite the guidelines, lower blood pressure might be unhealthy for kidney patients

Date:
June 24, 2010
Source:
American Society of Nephrology
Summary:
Recent guidelines by the National Kidney Foundation Disease Outcomes Quality Initiative call for lower target blood pressure levels in patients with chronic kidney disease. But in the absence of high-quality scientific evidence, there's a chance this recommendation could do more harm than good, according to a new article.
Share:
FULL STORY

Recent guidelines by The National Kidney Foundation Disease Outcomes Quality Initiative (NKF KDOQI)1 call for lower target blood pressure levels in patients with chronic kidney disease (CKD). But in the absence of high-quality scientific evidence, there's a chance this recommendation could do more harm than good, according to a special article appearing in an upcoming issue of the Journal of the American Society Nephrology (JASN).

"The new low blood pressure goals are not definitively supported by data, would be costly to the healthcare system and potentially harmful to patients," according to Julia B. Lewis, MD (Vanderbilt University, Nashville, TN), who performed a critical review of the research evidence.

Issued last year, updated national guidelines for CKD treatment call for a target blood pressure level of less than 130/80 mm Hg (millimeters of mercury) to help preserve kidney function. The recommendation was based on observational studies showing "a continuous benefit of reducing blood pressure to lower and lower levels."

However, Lewis points out several problems with the research behind the new guidelines. Most importantly, since patients in the observational studies were not randomly assigned to different blood pressure goals, the apparent benefit of lower blood pressures could result from other "confounding" factors. "The data supporting the current blood pressure guidelines for patients with CKD do not meet the standard of a primary outcome of a randomized trial," says Lewis.

She explains that, as kidney disease worsens, blood pressure rises and becomes harder to control. So the data may simply reflect the fact that patients with less severe kidney disease have lower blood pressure. In studies where patients were randomly assigned to treatments, the benefits of lower blood pressure were seen only in a subgroup of patients, or several years after the end of treatment.

"Also there is other evidence to bring into question the widespread application of this costly goal of a blood pressure less than 130/80 mm Hg," Lewis adds. Some studies have even suggested that CKD patients with very low blood pressure could be at increased risk of death.

A new trial sponsored by the National Institutes of Health (NIH) will compare the effects of different blood pressure targets in over 10,000 patients with CKD. Until the results are available, Lewis believes that doctors should make individualized decisions about blood pressure control for their patients with kidney disease.

Lewis emphasizes that no firm conclusions can be drawn from her review, since it was based on different types of studies with conflicting results.

The study author is a consultant for Thervance Pharmaceuticals, Covance Pharmaceuticals, and Amira Pharmaceuticals. She also receives research support from Keryx Pharmaceuticals, Nephrogenix, Eli Lilly, and the National Institutes of Diabetes and Digestive and Kidney Diseases (NIDDK).

1 K/DOQI Clinical Practice Guidelines on Hypertension and Antihypertensive Agents in Chronic Kidney Disease. Guideline 7: Pharmacological therapy: Use of antihypertensive agents in CKD. National Kidney Foundation. Available at: http://www.kidney.org/professionals/kdoqi/ guidelines_bp/guide_7.htm. Accessed May 10, 2010.


Story Source:

Materials provided by American Society of Nephrology. Note: Content may be edited for style and length.


Journal Reference:

  1. Julia B. Lewis. Blood Pressure Control in Chronic Kidney Disease: Is Less Really More? Journal of the American Society Nephrology, 2010; DOI: 10.1681/ASN.2010030236

Cite This Page:

American Society of Nephrology. "Despite the guidelines, lower blood pressure might be unhealthy for kidney patients." ScienceDaily. ScienceDaily, 24 June 2010. <www.sciencedaily.com/releases/2010/06/100624183006.htm>.
American Society of Nephrology. (2010, June 24). Despite the guidelines, lower blood pressure might be unhealthy for kidney patients. ScienceDaily. Retrieved March 28, 2024 from www.sciencedaily.com/releases/2010/06/100624183006.htm
American Society of Nephrology. "Despite the guidelines, lower blood pressure might be unhealthy for kidney patients." ScienceDaily. www.sciencedaily.com/releases/2010/06/100624183006.htm (accessed March 28, 2024).

Explore More

from ScienceDaily

RELATED STORIES