Kidneys: Produce-rich diet improves long-term health, melatonin improves short-term health

1. Kidney Disease Patients Benefit from a Diet High in Fruits and Vegetables
Healthy Foods Can Help Maintain Kidney Function

In patients with kidney disease, the Western diet produces an acidic environment in the body that has numerous negative effects and worsens with age as kidney function declines. Nimirit Goraya, MD (Texas A&M College of Medicine and Scott and White Healthcare) and her colleagues conducted a study to see if consuming a diet high in fruits and vegetables that counteract this acidity might improve the kidney health of 40 patients who have moderately reduced kidney function due to high blood pressure. 30 days of this diet reduced urine excretion of three indicators of kidney injury: albumin, transforming growth factor, and N-acetyl-β-D- glucosaminidase. "These preliminary studies support the need for larger long-term studies to determine if this simple and relatively inexpensive intervention helps reduce the risk of subsequent worsening of kidney function in patients with hypertension-associated kidney disease," said Dr. Goraya.

Study co-authors include Jan Simoni, PhD (Texas Tech University Health Sciences); Kristine Broglio (Texas A&M University); and Donald E. Wesson, MD (Texas A&M College of Medicine and Scott and White Healthcare).

Disclosures: The authors reported no financial disclosures.

The study abstract, "Adding Dietary Fruits and Vegetables Reduces Kidney Injury in Subjects with Moderately Reduced GFR," [SA-PO2343] will be presented as a poster on Saturday, November 20, 2010 from 10:00 AM - 12:00 PM MT in Exhibit Halls A & F of the Colorado Convention Center in Denver, CO.

2. Melatonin Improves Dialysis Patients' Sleep
Hormone's Effects Do Not Persist, Though

Sleep disorders are common in kidney disease patients on dialysis due to a disturbance in their biological clocks. Marije Russcher, PharmD, Birgit Koch, PharmD, PhD, (Meander Medical Center, in Amersfoort, the Netherlands) and colleagues previously found that giving dialysis patients melatonin, a hormone that helps regulate sleep and wake cycles, can improve sleep over a short period of time. Now, these researchers have investigated whether the benefits of melatonin on sleep persist over the long term, and if long-term use of melatonin could improve patients' quality of life. 70 dialysis patients received melatonin or a placebo for 1 year. At 3 months, the previously shown beneficial effect of the short-term use of melatonin on sleep onset was confirmed. The investigators also noted improvement of sleep efficiency and sleep time. In contrast, at 12 months none of the measured sleep parameters differed significantly from placebo. Regarding quality of life, melatonin had a positive effect on social functioning and a trend in improvement of mentality. "We confirmed the short term beneficial effects of melatonin on sleep; however, we found no indication that these beneficial effects persist in long-term usage of melatonin," said Ms. Russcher. "Further research should focus on optimizing melatonin dosage and time of dosing, specifically in kidney patients."

Study co-authors include Ernst Hagen, MD, PhD, Elsbeth Nagtegaal, PharmD, PhD, Monique van der Westerlaken, PharmD (Meander Medical Center, in Amersfoort, the Netherlands); Carlo Gaillard, MD, PhD (Meander Medical Center, in Amersfoort and the VU Medical Center, in Amsterdam, the Netherlands); Frans van Ittersum, MD, PhD and Pieter M. Ter Wee, MD, PhD (the VU Medical Center, in Amsterdam, the Netherlands), Wim van Dorp, MD, PhD (Kennemer Hospital, in Haarlem, the Netherlands), Bas Gabreëls, MD, PhD (Rijnland Hospital, in Leiderdorp, the Netherlands)

Disclosures: Dr. Ter Wee receives research support from Abbott, Baxter, Gambro, Fresenius, and Roche and honoraria from Amgen, Roche, Genzyme, and Fresenius. All other authors reported no financial disclosures.

The study abstract, "The Long-Term Effects of Melatonin on Sleep and Quality of Life in Hemodialysis Patients," [SA-PO2333] will be presented as a poster on Saturday, November 20, 2010 from 10:00 AM - 12:00 PM MT in Exhibit Halls A & F of the Colorado Convention Center in Denver, CO.

Provided by American Society of Nephrology