Increased kidney growth in formula-fed versus breast-fed healthy infants

Pediatr Nephrol. 2004 Oct;19(10):1137-44. doi: 10.1007/s00467-004-1567-0. Epub 2004 Aug 11.

Abstract

A high protein intake results in increased kidney growth and glomerular filtration rate in human adults and young rats. It is unknown whether kidney size in young infants is influenced by increased protein intake in formula-fed compared with breast-fed infants. We investigated the effect of formula versus breast feeding on kidney growth in a cohort of 631 healthy children examined at birth, and at 3 and 18 months of age. Kidney size was determined by ultrasonography and related to gender, age, body size, and feeding category (fully breast fed, partially breast fed, or fully formula fed at 3 months). Serum urea nitrogen, serum creatinine, and estimated creatinine clearance were measured at 3 months of age. Kidney growth and serum urea nitrogen were significantly increased in partially or fully formula-fed 3-month-old infants. This effect was more pronounced in boys than in girls. The changes in relative kidney size were temporary, as they did not persist at 18 months of age, when all children received a normal mixed diet. The immediate renal effects of formula feeding should be taken into consideration for recommendations concerning infant feeding. Whether there are any long-term effects of early increased protein intake on later kidney function remains to be seen.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blood Urea Nitrogen
  • Breast Feeding*
  • Creatinine / blood
  • Dietary Proteins / pharmacology
  • Female
  • Humans
  • Infant
  • Infant Formula / pharmacology*
  • Infant, Newborn
  • Kidney / drug effects
  • Kidney / growth & development*
  • Male
  • Organ Size / drug effects
  • Organ Size / physiology
  • Prospective Studies

Substances

  • Dietary Proteins
  • Creatinine