title: Protein intake in infancy and kidney size and function at the age of 6 years: The Generation R Study.
abstract: BACKGROUND
  High protein intake has been linked to kidney growth and function. Whether protein intake is related to kidney outcomes in healthy children is unclear.
  
  
  METHODS
  We examined the associations between protein intake in infancy and kidney outcomes at age 6 years in 2968 children participating in a population-based cohort study. Protein intake at 1 year was assessed using a food-frequency questionnaire and was adjusted for energy intake. At age 6 years we measured the kidney volume and urinary albumin/creatinine ratio (ACR) of all participating children, and we estimated glomerular filtration rate (eGFR) using serum creatinine and cystatin C levels.
  
  
  RESULTS
  In models adjusted for age, sex, body surface area, and sociodemographic factors, a higher protein intake was associated with a lower ACR and a higher eGFR but was not consistently associated with kidney volume. However, after further adjustment for additional dietary and lifestyle factors, such as sodium intake, diet quality, and television watching, higher protein intake was no longer associated with kidney function. No differences in associations were observed between animal and vegetable protein intake.
  
  
  CONCLUSIONS
  Our findings show that protein intake in early childhood is not independently associated with kidney size or function at the age of 6 years. Further study is needed on other early life predictors of kidney size and function in later life.
authors.affiliation: The Generation R Study Group, Erasmus MC, University Medical Center, Rotterdam, The Netherlands, trudy.voortman@erasmusmc.nl.
authors.forename: Trudy
authors.initials: T
authors.lastname: Voortman
authors.forename: Hanneke
authors.initials: H
authors.lastname: Bakker
authors.forename: Sanaz
authors.initials: S
authors.lastname: Sedaghat
authors.forename: Jessica C
authors.initials: JC
authors.lastname: Kiefte-de Jong
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.forename: Vincent W V
authors.initials: VW
authors.lastname: Jaddoe
authors.forename: Oscar H
authors.initials: OH
authors.lastname: Franco
authors.forename: Edith H
authors.initials: EH
authors.lastname: van den Hooven
mesh_terms: D002648:Child; D002675:Child, Preschool; D003404:Creatinine / Q000097:blood*; D055316:Cystatin C / Q000097:blood*; D004044:Dietary Proteins / Q000008:administration & dosage*; D002149:Energy Intake / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006801:Humans; D007223:Infant; D007668:Kidney / Q000033:anatomy & histology* / Q000502:physiology; D007677:Kidney Function Tests; D008297:Male; D015596:Nutrition Assessment; D011446:Prospective Studies; D012016:Reference Values
chemical_list: D055316:Cystatin C; D004044:Dietary Proteins; D003404:Creatinine