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Wednesday, November 16, 2011

Alternative meds and the kidney


PHILADELPHIA -- From 10% to 15% of patients with chronic kidney disease reported using potentially nephrotoxic dietary supplements, an analysis of a large government database showed.

http://www.medpagetoday.com/MeetingCoverage/ASN/29627

The National Kidney Foundation provides a list of herbs to help you decide what has been proven harmful.

http://www.kidney.org/atoz/content/herbalsupp.cfm

In an associated article

Dietary Supplements May Be Harmful in CKD

 http://www.medscape.com/viewarticle/753293?sssdmh=dm1.738630&src=confwrap


November 10, 2011 (Philadelphia, Pennsylvania) — Patients with all stages of chronic kidney disease (CKD) often take dietary supplements that neither they nor their healthcare providers are aware might be harmful in light of the patients' health conditions, researchers warned during a poster session here at Kidney Week 2011: American Society of Nephrology 44th Annual Meeting.
After examining data from the 1999 to 2008 National Health and Nutrition Examination Survey (NHANES), Vanessa Grubbs, MD, MPH, assistant professor in the division of nephrology at San Francisco General Hospital, and assistant adjunct professor at the University of California at San Francisco School of Medicine, and colleagues found that more than 1 of 7 survey participants reported taking at least 1 supplement containing any herb that the National Kidney Foundation (NKF) has listed as possibly harmful to patients with CKD.
Dr. Vanessa Grubbs
Dr. Grubbs and colleagues used the NHANES data to examine the reported use of a dietary supplement in the previous 30 days by 21,169 nonpregnant adults. The surveyed individuals were classified as not having CKD, having stage 1/2 CKD (urinary albumin/creatinine ratio of at least 30 mg/g, with estimated glomerular filtration rate of at least 60 mL/min per 1.73 m²), or having stage 3/4 CKD (estimated glomerular filtration rate of 15 to 59 mL/min per 1.73 m²). The researchers considered any supplement that contained at least 1 herb on the NKF list to be harmful.
An estimated 52.4% of respondents reported taking a dietary supplement, and 15.3% took a potentially harmful one. The crude estimated prevalence of taking any dietary supplement increased with CKD severity, but the use of a potentially harmful supplement decreased as severity increased. However, after adjustment for demographics, comorbid disease, and healthcare visits, the investigators found no correlation between CKD severity and the use of any supplement or a potentially harmful one.
The use of supplements by CKD patients was not statistically different than use by individuals without CKD.
Dietary Supplement Use by Patients With CKD*
CKD Stage
Any supplement,
OR (95% CI)
Any potentially harmful supplement,
OR (95% CI)
1/2 0.95 (0.82–1.10) 0.97 (0.73–1.28)
3/4 1.07 (0.93–1.23) 0.90 (0.67–1.21)
OR, odds ratio; CI, confidence interval
*After adjustment for demographics, comorbidity, and healthcare visits; compared with no CKD

The investigators conclude that patients with CKD often use dietary supplements, and some of them are harmful. Because the use of these supplements does not differ according to severity of kidney disease, they speculate that patients are not aware of the potential harm. They caution that healthcare providers, too, might be unaware of the potential risk associated with certain supplements, and might be unaware that their CKD patients are taking them.
This is important because the vast majority of people who have kidney disease "are not aware that they have kidney disease. Even among people who have advanced kidney disease, less than 10% are aware that they have this disease," Dr. Grubbs noted. Compounding the problem is the fact that it is not known how many of the vast array of dietary supplements are potentially harmful, "in part because of the way supplements are regulated." She explained that "people are taking these supplements because they think they are improving their health, so the fact they can actually cause harm that is entirely preventable is an important point."
On the basis of the study findings, Dr. Grubbs has several recommendations. First, she said, everyone should find out if he or she has kidney disease — which can be done with simple blood and urine tests. Then patients should tell their healthcare providers everything that they are taking.
Providers need to educate themselves about dietary supplements, because they generally do not get that sort of information in their training. "Then we need to be vigilant in asking patients about everything that they're taking because they tend not to disclose," she said.
Because dietary supplements are regulated as foods, not drugs, they can be marketed to consumers without any proof of safety or efficacy. Dr. Grubbs suggested that "policy makers really need to update the law that governs dietary supplements," and require them to be safe and to "live up to the various claims that they make."
Katherine Tuttle, MD, executive director for research at Providence Sacred Heart Medical Center and professor of medicine at the University of Washington School of Medicine in Spokane, who moderated the session and was not involved in the study, told Medscape Medical News that this research explores an important area for clinicians. "Every time we go to clinic, people are on supplements. I think raising awareness around them is extremely important," she said. In her opinion, the investigators have made good use of the NHANES data to bring visibility to the issue.
For clinicians, she said, "at a minimum, we need to make sure that when we query patients about medicines, [we ask about] things...they might buy over the counter or at a health food store...and [then check] available databases to see if any of those things are potentially harmful." Her practice is not to object if her investigation does not reveal any harms and the patient seems to be doing all right. "But there are some [supplements] that are known to be harmful; we need to counsel people to avoid those," Dr. Tuttle advised.
The list of herbs that can be toxic to the kidneys, harmful in CKD, or unsafe for all people, can be found on the NKF Web site. The NKF warns that this list is not exhaustive, and encourages caution with all herbal preparations and consultation with knowledgeable medical professionals.
The study received no commercial funding. Dr. Grubbs has disclosed no relevant financial relationships.
KKidney Week 2011: American Society of Nephrology 44th Annual Meeting: Abstract TH-PO267. Presented November 10, 2011.

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