title: Dietary acid load and chronic kidney disease among adults in the United States.
abstract: BACKGROUND
  Diet can markedly affect acid-base status and it significantly influences chronic kidney disease (CKD) and its progression. The relationship of dietary acid load (DAL) and CKD has not been assessed on a population level. We examined the association of estimated net acid excretion (NAE(es)) with CKD; and socio-demographic and clinical correlates of NAE(es).
  
  
  METHODS
  Among 12,293 U.S. adult participants aged >20 years in the National Health and Nutrition Examination Survey 1999-2004, we assessed dietary acid by estimating NAE(es) from nutrient intake and body surface area; kidney damage by albuminuria; and kidney dysfunction by eGFR < 60 ml/min/1.73 m(2) using the MDRD equation. We tested the association of NAE(es) with participant characteristics using median regression; while for albuminuria, eGFR, and stages of CKD we used logistic regression.
  
  
  RESULTS
  Median regression results (β per quintile) indicated that adults aged 40-60 years (β [95% CI] = 3.1 [0.3-5.8]), poverty (β [95% CI] = 7.1 [4.01-10.22]), black race (β [95% CI] = 13.8 [10.8-16.8]), and male sex (β [95% CI] = 3.0 [0.7- 5.2]) were significantly associated with an increasing level of NAE(es). Higher levels of NAE(es) compared with lower levels were associated with greater odds of albuminuria (OR [95% CI] = 1.57 [1.20-2.05]). We observed a trend toward greater NAE(es) being associated with higher risk of low eGFR, which persisted after adjustment for confounders.
  
  
  CONCLUSIONS
  Higher NAE(es) is associated with albuminuria and low eGFR, and socio-demographic risk factors for CKD are associated with higher levels of NAE(es). DAL may be an important target for future interventions in populations at high risk for CKD.
authors.affiliation: Department of Medicine, University of California, San Francisco, CA, USA. banerjeet@medsfgh.ucsf.edu.
authors.forename: Tanushree
authors.initials: T
authors.lastname: Banerjee
authors.forename: Deidra C
authors.initials: DC
authors.lastname: Crews
authors.forename: Donald E
authors.initials: DE
authors.lastname: Wesson
authors.forename: Anca
authors.initials: A
authors.lastname: Tilea
authors.forename: Rajiv
authors.initials: R
authors.lastname: Saran
authors.forename: Nilka
authors.initials: N
authors.lastname: Rios Burrows
authors.forename: Desmond E
authors.initials: DE
authors.lastname: Williams
authors.forename: Neil R
authors.initials: NR
authors.lastname: Powe
mesh_terms: D000138:Acidosis / Q000175:diagnosis / Q000453:epidemiology* / Q000378:metabolism*; D000328:Adult; D003430:Cross-Sectional Studies; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys / Q000379:methods*; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis / Q000453:epidemiology* / Q000378:metabolism*; D014481:United States / Q000453:epidemiology