title: The relationship between estimated sodium and potassium excretion and subsequent renal outcomes.
abstract: Patients are often advised to reduce sodium and potassium intake, but supporting evidence is limited. To help provide such evidence we estimated 24 h urinary sodium and potassium excretion in 28,879 participants at high cardiovascular risk who were followed for a mean of 4.5 years in the ONTARGET and TRANSCEND trials. The primary outcome was eGFR decline of 30% or more or chronic dialysis. Secondary outcomes were eGFR decline of 40% or more or chronic dialysis, doubling of serum creatinine or chronic dialysis, an over 5%/year loss of eGFR, progression of albuminuria, and hyperkalemia. Multinomial logit regression with multivariable fractional polynomials, adjusted for confounders, determined the association between urinary sodium and potassium excretion and renal outcomes, with death as a competing risk. The primary outcome occurred in 2,052 (7.6%) patients. There was no significant association between sodium and any renal outcome (primary outcome odds ratio 0.99; 95% CI 0.89-1.09 for highest [median 6.2 g/day] vs. lowest third [median 3.3 g/day]). Higher potassium was associated with lower odds of all renal outcomes (primary outcome odds ratio 0.74; 95% CI 0.67-0.82 for highest [median 2.7 g/day] vs. lowest third [median 1.7 g/day], except hyperkalemia nonsignificant. Thus, urinary potassium, but not sodium, excretion predicted clinically important renal outcomes. Our findings do not support routine low sodium and potassium diets for prevention of renal outcomes in people with vascular disease with or without chronic kidney disease.
authors.affiliation: 1] Health Research Board Clinical Research Facility Galway, National University of Ireland, Galway, Ireland [2] Population Health Research Institute, McMaster University, Hamilton, ON, Canada.
authors.forename: Andrew
authors.initials: A
authors.lastname: Smyth
authors.affiliation: 1] Population Health Research Institute, McMaster University, Hamilton, ON, Canada [2] Department of Nephrology, University of Erlangen-Nürnberg and Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Vienna, Austria.
authors.forename: Daniela
authors.initials: D
authors.lastname: Dunkler
authors.affiliation: Population Health Research Institute, McMaster University, Hamilton, ON, Canada.
authors.forename: Peggy
authors.initials: P
authors.lastname: Gao
authors.affiliation: Population Health Research Institute, McMaster University, Hamilton, ON, Canada.
authors.forename: Koon K
authors.initials: KK
authors.lastname: Teo
authors.affiliation: Population Health Research Institute, McMaster University, Hamilton, ON, Canada.
authors.forename: Salim
authors.initials: S
authors.lastname: Yusuf
authors.affiliation: 1] Health Research Board Clinical Research Facility Galway, National University of Ireland, Galway, Ireland [2] Population Health Research Institute, McMaster University, Hamilton, ON, Canada.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: O'Donnell
authors.affiliation: 1] Population Health Research Institute, McMaster University, Hamilton, ON, Canada [2] Department of Nephrology, University of Erlangen-Nürnberg and Munich General Hospitals, Munich, Germany.
authors.forename: Johannes F E
authors.initials: JF
authors.lastname: Mann
authors.affiliation: Department of Nephrology, McMaster University, Hamilton, ON, Canada.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Clase
mesh_terms: D000368:Aged; D000419:Albuminuria / Q000652:urine; D003404:Creatinine / Q000097:blood; D018450:Disease Progression; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D006947:Hyperkalemia / Q000097:blood; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood / Q000652:urine*; D006435:Renal Dialysis; D051436:Renal Insufficiency, Chronic / Q000503:physiopathology*; D012964:Sodium / Q000652:urine*
chemical_list: D012964:Sodium; D003404:Creatinine; D011188:Potassium