title: New approach shows no association between maternal milk fatty acid composition and childhood wheeze or asthma.
abstract: BACKGROUND
  Previous observational studies have implied breastmilk fatty acid composition may play a role in the development of atopic eczema or atopic sensitization in breastfed infants and toddlers. However, studies investigating associations with wheeze and asthma in later childhood are scarce and did not account for inherent correlation of compositional data. Our aim was to explore the association of maternal milk fatty acid composition with childhood wheezing phenotypes and asthma up to age 13 years using a new statistical approach.
  
  
  METHODS
  Breastmilk was collected 6 weeks and 6 months postdelivery in the Ulm Birth Cohort Study (n=720 and n=454, respectively). Concentrations of 28 fatty acids were measured by high-resolution capillary gas-liquid chromatography. To control for constant-sum constraint, concentration data were transformed using the centered log ratio method. Compositional biplots and correlation matrices were used to group centered log ratio transformed fatty acids. Adjusted risk ratios with parent-reported wheezing phenotypes and doctor-diagnosed asthma were computed using a modified Poisson regression.
  
  
  RESULTS
  We observed no straightforward evidence of associations between overall breastmilk fatty acid composition and specific wheeze phenotypes or doctor-diagnosed asthma.
  
  
  CONCLUSIONS
  Using appropriate statistical methodology, we report null associations. These findings may partly be attributable to several cohort-specific factors associated with breastfeeding and breastmilk collection. Further studies could improve on ours by analyzing samples of breastmilk and formula and by including all children for whom these are exclusively or together the major source of fatty acids in the first months of life.
authors.affiliation: Institute of Epidemiology and Medical Biometry, Ulm University, Ulm, Germany.
authors.forename: C A
authors.identifier: http://orcid.org/0000-0002-6157-3641
authors.initials: CA
authors.lastname: Logan
authors.affiliation: Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, University Medical Center Ulm, Ulm, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Brandt
authors.affiliation: Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, University Medical Center Ulm, Ulm, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Wabitsch
authors.affiliation: Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Brenner
authors.affiliation: Human Milk Research, Nutricia Research, Utrecht, The Netherlands.
authors.forename: F
authors.initials: F
authors.lastname: Wiens
authors.affiliation: Human Milk Research, Nutricia Research, Utrecht, The Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: Stahl
authors.affiliation: Department of Paediatrics, University of Pécs, Pécs, Hungary.
authors.forename: T
authors.initials: T
authors.lastname: Marosvölgyi
authors.affiliation: Department of Paediatrics, University of Pécs, Pécs, Hungary.
authors.forename: T
authors.initials: T
authors.lastname: Decsi
authors.affiliation: Institute of Epidemiology and Medical Biometry, Ulm University, Ulm, Germany.|Member of "In-FLAME" the International Inflammation Network, World Universities Network (WUN).
authors.forename: D
authors.initials: D
authors.lastname: Rothenbacher
authors.affiliation: Institute of Epidemiology and Medical Biometry, Ulm University, Ulm, Germany.|Member of "In-FLAME" the International Inflammation Network, World Universities Network (WUN).
authors.forename: J
authors.identifier: http://orcid.org/0000-0001-5764-1528
authors.initials: J
authors.lastname: Genuneit
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000209:etiology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005227:Fatty Acids / Q000009:adverse effects / Q000032:analysis*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007223:Infant; D008297:Male; D008895:Milk, Human / Q000737:chemistry*; D016017:Odds Ratio; D012135:Respiratory Sounds / Q000209:etiology*
chemical_list: D005227:Fatty Acids
keywords: asthma; fatty acids; human milk; wheeze