NOV EMBER /DECEMBER 2015
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VOL UME 14, IS SUE NUMBER 9
Long HD Gap Ups Hyperkalemia Risk Mortality more likely with elevated potassium BY JODY A. CHARNOW SAN DIEGO—Hyperkalemia rates are more than twice as high on the day after the long versus short interdialytic interval among patients on thrice-weekly hemodialysis (HD), and the condition is associated with an increased risk of death, according to separate studies presented at Kidney Week by the same research team. In a retrospective study comparing the frequency of hyperkalemia on the day after the long and short interdialytic interval, James B. Wetmore, MD, and Akeem Yusuf, PhD, of Hennepin
IN THIS ISSUE 5
Hyperkalemia drug receives FDA approval
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Ascorbic acid supplements safe for hemodialysis patients
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Tolvaptan may lower the risk of kidney stones
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Home dialysis use declined after physician payment reform
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Urbanization proposed as a kidney stone risk factor
City living may predispose people to kidney stones. PAGE 16
County Medical Center in Minneapolis, Minn., and colleagues analyzed data from 4 annual cohorts of HD patients: 2007 (28,769 patients), 2008 (34,785 patients), 2009 (34,567 patients), and 2010 (36,879 patients). The prevalence of hyperkalemia events per 100 patientmonths on the day after the long interdialytic interval in 2007, 2008, 2009, and 2010 was 58.7, 62.2, 62.9, and 61.6, respectively. By comparison, the prevalence of hyperkalemia events on the day after the short interdialytic interval was 28.8, 27.6, 26.3, and 26.2, respectively.
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INTERDIALYTIC INTERVAL AND HYPERKALEMIA RISK A study of 4 annual cohorts of patients on thrice-week hemodialysis (2007, 2008, 2009, and 2010) found that -hyperkalemia occurs more frequently on the day after the long versus the short interdialytic interval. 80
80
2007
70
70 60
2008
60 50
50
40
40
30
30
20
20
10
10
0
58.7
62.2
62.9
61.6
Day after long interval
0
2009 2010
28.8
27.6
26.3
26.2
Day after short interval
Events per 100 patients-months Source: Yusuf A et al. Frequency of hyperkalemia events in dialysis patients in a large dialysis organization. Poster presented at Kidney Week 2015, San Diego.
“Hyperkalemia is substantially more common on the day after the long, 72-hour interdialytic interval compared to the short, 48-hour interval,” Dr. Wetmore told Renal & Urology News. “Since hyperkalemia is likely related to death and cardiac events in
hemodialysis patients, this raises the possibility that the hyperkalemia is a mechanism at least partially responsible for the increased rates of death and cardiovascular events after the long interdialytic interval.” continued on page 6
Kidney Stones Biomarker Predicts CKD Earlier in Men Linked BY JODY A. CHARNOW Reiser, MD, PhD, of Rush University SAN DIEGO—Elevated levels of a Medical Center in Chicago, meato Vitamin C certain plasma biomarker indepen- sured plasma suPAR levels in 3,683 TOTAL AND supplemental vitamin C intake is associated with a significantly elevated risk of kidney stones in men, according to a new study published online ahead of print in the American Journal of Kidney Diseases. In a prospective cohort analysis, Pietro Manuel Ferraro, MD, of ColumbusGemelli University Hospital, Catholic University of the Sacred Heart in Rome, Italy, and colleagues found that total vitamin C intake of 90–249, 250–499, 500–999, and 1,000 mg/day or higher was associated with a 19%, 15%, 29%, and 43% increased risk of kidney stones among men compared with an continued on page 6
dently predict an increased risk of chronic kidney disease (CKD) before any decline in estimated glomerular filtration rate (eGFR) occurs in patients with normal kidney function, according to new study findings presented at Kidney Week and published in The New England Journal of Medicine. The biomarker is soluble urokinasetype plasminogen activator receptor (suPAR), which is expressed on a variety of cells, including immunologically active cells, endothelial cells, and podocytes. A team led by Jochen
CME FEATURE
individuals enrolled in the Emory Cardiovascular Biobank and determined renal function at enrollment and at subsequent visits in 2,292 of them. “SuPAR promises to do for kidney disease what cholesterol has done for cardiovascular disease,” Dr. Reiser said in a press release issued by his medical center, where he is the Ralph C. Brown, M.D., professor and chairman of medicine. Results showed that a higher suPAR level at baseline was associated with faster decline in eGFR during follow-up. continued on page 6
Earn 1 CME credit
SGLT-2 Inhibitors for Type 2 Diabetes: Renal and Urinary Considerations PAGE 19