Featured Research

from universities, journals, and other organizations

Study evaluates association between urinary salt excretion and risk of cardiovascular events or death

Date:
November 29, 2011
Source:
JAMA and Archives Journals
Summary:
For persons with cardiovascular disease or diabetes, urinary sodium excretion (a surrogate for salt intake) at higher levels or at lower levels compared to mid-range values was associated with an increased risk of cardiovascular events (for higher levels) or cardiovascular death and hospitalization for congestive heart failure (for lower levels), according to a new study. Also, higher estimated urinary potassium excretion was associated with a reduced risk of stroke.

For persons with cardiovascular disease or diabetes, urinary sodium excretion (a surrogate for salt intake) at higher levels or at lower levels compared to mid-range values was associated with an increased risk of cardiovascular events (for higher levels) or cardiovascular death and hospitalization for congestive heart failure (for lower levels), according to a study in the Nov. 23/30 issue of JAMA. Also, higher estimated urinary potassium excretion was associated with a reduced risk of stroke.

There is uncertainty regarding the optimal daily intake of sodium. Findings from prospective cohort studies, evaluating the association between sodium intake and cardiovascular (CV) events, have been conflicting. "Clarifying the optimal daily intake of sodium is particularly important in patients with established CV disease, where it has been inadequately studied. Patients with CV disease may be especially vulnerable to the CV effects of high and low sodium intake and are most likely to receive recommendations on restricting sodium intake," according to background information in the article. The authors add that the optimal level of daily potassium intake, a proposed modifier of the association between sodium intake and CV disease, has not been established.

Martin J. O'Donnell, M.B., Ph.D., of McMaster University, Hamilton, Ontario, Canada, and colleagues examined the association between sodium and potassium excretion (markers of intake) and CV events and mortality. The study consisted of an observational analyses of 2 cohorts (n = 28,880) included in the ONTARGET and TRANSCEND trials (November 2001-March 2008 from initial recruitment to final follow-up). The researchers estimated 24-hour urinary sodium and potassium excretion from a morning fasting urine sample. Multivariable models were used to determine the association of urinary sodium and potassium with CV events (myocardial infarction [MI; heart attack], stroke, and hospitalization for congestive heart failure (CHF) and mortality.

At study entry, the average estimated 24-hour excretion for sodium was 4.77 g and 2.19 g for potassium. After a median (midpoint) follow-up of 56 months, the composite outcome occurred in 4,729 (16.4 percent) participants. The researchers found that after multivariable analysis, compared with baseline sodium excretion of 4 to 5.99 g per day (n = 14,156 [15.2 percent with the composite outcome]), higher baseline sodium excretion (18.4 percent for 7-8 g/d and 24.1 percent for greater than 8 g/d) and lower sodium excretion (18.2 percent for 2-2.99 g/d and 20.2 percent for less than 2g/d) were associated with an increased risk of the composite of CV death, heart attack, stroke, and hospitalization for CHF.

Compared with the reference group, higher baseline sodium excretion was associated with an increased risk of CV death (9.7 percent for 7-8 g/day; and 11.2 percent for greater than 8 g/day), MI (6.8 percent for greater than 8 g/day), stroke (6.6 percent for greater than 8 g/day), and hospitalization for CHF (6.5 percent for greater than 8 g/day). Lower sodium excretion was associated with an increased risk of CV death (8.6 percent for 2-2.99 g/day; 10.6 percent for less than 2 g/day), and hospitalization for CHF (5.2 percent for 2-2.99 g/day) on multivariable analysis. Compared with an estimated potassium excretion of less than 1.5 g per day, higher potassium excretion was associated with a reduced risk of stroke on multivariable analysis.

The researchers note that previous individual prospective cohort studies have either reported a positive association, no association, or an inverse relationship between sodium intake and CV mortality. "Discrepant findings of previous studies are likely due to differences in ranges of sodium intake, study populations, methods of measurement, and failure to explore a nonlinear association."

"Compared with moderate sodium excretion, we found an association between high sodium excretion and CV events and low sodium excretion and CV death and hospitalization for CHF, which emphasizes the urgent need to establish a safe range for sodium intake in randomized controlled trials. Higher urinary potassium excretion was associated with lower stroke risk and is a potential intervention that merits further evaluation for stroke prevention."

Editorial: Urinary Sodium and Cardiovascular Disease Risk

In an accompanying editorial, Paul K. Whelton, M.B., M.D., M.Sc., of the Tulane University School of Public Health and Tropical Medicine, New Orleans, comments on the importance of reducing salt intake.

"Most U.S. adults consume levels of sodium far in excess of physiologic need, and the vast majority of that excess is added during the processing of foods. A progressive reduction in the addition of sodium to food products could represent one of the 'lifestyle' changes with the greatest potential for intervention success. This shift to a more natural diet would concurrently lead to an absolute increase in dietary potassium content and also lead to an improved sodium-potassium ratio, which may be more desirable than change of either electrolyte on its own. The scientific underpinning for the health benefits from sodium reduction is strong, and the available evidence does not support deviating from the stated goal of reducing the exposure to dietary sodium in the general population."


Story Source:

The above story is based on materials provided by JAMA and Archives Journals. Note: Materials may be edited for content and length.


Journal References:

  1. M. J. O'Donnell, S. Yusuf, A. Mente, P. Gao, J. F. Mann, K. Teo, M. McQueen, P. Sleight, A. M. Sharma, A. Dans, J. Probstfield, R. E. Schmieder. Urinary Sodium and Potassium Excretion and Risk of Cardiovascular Events. JAMA: The Journal of the American Medical Association, 2011; 306 (20): 2229 DOI: 10.1001/jama.2011.1729
  2. P. K. Whelton. Urinary Sodium and Cardiovascular Disease Risk: Informing Guidelines for Sodium Consumption. JAMA: The Journal of the American Medical Association, 2011; 306 (20): 2262 DOI: 10.1001/jama.2011.1746

Cite This Page:

JAMA and Archives Journals. "Study evaluates association between urinary salt excretion and risk of cardiovascular events or death." ScienceDaily. ScienceDaily, 29 November 2011. <www.sciencedaily.com/releases/2011/11/111122162820.htm>.
JAMA and Archives Journals. (2011, November 29). Study evaluates association between urinary salt excretion and risk of cardiovascular events or death. ScienceDaily. Retrieved September 16, 2014 from www.sciencedaily.com/releases/2011/11/111122162820.htm
JAMA and Archives Journals. "Study evaluates association between urinary salt excretion and risk of cardiovascular events or death." ScienceDaily. www.sciencedaily.com/releases/2011/11/111122162820.htm (accessed September 16, 2014).

Share This



More Health & Medicine News

Tuesday, September 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

President To Send 3,000 Military Personnel To Fight Ebola

President To Send 3,000 Military Personnel To Fight Ebola

Newsy (Sep. 16, 2014) President Obama is expected to send 3,000 troops to West Africa as part of the effort to contain Ebola's spread. Video provided by Newsy
Powered by NewsLook.com
Man Floats for 31 Hours in Gulf Waters

Man Floats for 31 Hours in Gulf Waters

AP (Sep. 16, 2014) A Texas man is lucky to be alive after he and three others floated for more than a day in the Gulf of Mexico when their boat sank during a fishing trip. (Sept. 16) Video provided by AP
Powered by NewsLook.com
EU Ministers and Experts Meet to Discuss Ebola Reponse

EU Ministers and Experts Meet to Discuss Ebola Reponse

AFP (Sep. 15, 2014) The European Commission met on Monday to coordinate aid that the EU can offer to African countries affected by the Ebola outbreak. Duration: 00:58 Video provided by AFP
Powered by NewsLook.com
Despite The Risks, Antibiotics Still Overprescribed For Kids

Despite The Risks, Antibiotics Still Overprescribed For Kids

Newsy (Sep. 15, 2014) A new study finds children are prescribed antibiotics twice as often as is necessary. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

More Coverage


Study Calls Sodium Intake Guidelines Into Question

Nov. 23, 2011 For years, doctors have warned that too much salt is bad for your heart. Now a new study suggests that both high and low levels of salt intake may put people with heart disease or diabetes at ... read more
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins