title: Fish oil supplementation from 9 to 18 months of age affects the insulin-like growth factor axis in a sex-specific manner in Danish infants.
abstract: Several studies have investigated the effects of fish oil (FO) on infant growth, but little is known about the effects of FO and sex on insulin-like growth factor-1 (IGF-1), the main regulator of growth in childhood. We explored whether FO v. sunflower oil (SO) supplementation from 9 to 18 months of age affected IGF-1 and its binding protein-3 (IGFBP-3) and whether the potential effects were sex specific. Danish infants (n 115) were randomly allocated to 5 ml/d FO (1·2 g/d n-3 long-chain PUFA (n-3 LCPUFA)) or SO. We measured growth, IGF-1, IGFBP-3 and erythrocyte EPA, a biomarker of n-3 LCPUFA intake and status, at 9 and 18 months. Erythrocyte EPA increased strongly with FO compared with SO (P<0·001). There were no effects of FO compared with SO on IGF-1 in the total population, but a sex × group interaction (P=0·02). Baseline-adjusted IGF-1 at 18 months was 11·1 µg/l (95% CI 0·4, 21·8; P=0·04) higher after FO compared with SO supplementation among boys only. The sex × group interaction was borderline significant in the model of IGFBP-3 (P=0·09), with lower IGFBP-3 with FO compared with SO among girls only (P=0·03). The results were supported by sex-specific dose-response associations between changes in erythrocyte EPA and changes in IGF-1 and IGFBP-3 (both P<0·03). Moreover, IGF-1 was sex specifically associated with BMI and length. In conclusion, FO compared with SO resulted in higher IGF-1 among boys and lower IGFBP-3 among girls. The potential long-term implications for growth and body composition should be investigated further.
authors.affiliation: 1Department of Nutrition,Exercise & Sports, Faculty of Science,University of Copenhagen,DK-1958 Frederiksberg C,Denmark.
authors.forename: Camilla T
authors.initials: CT
authors.lastname: Damsgaard
authors.affiliation: 1Department of Nutrition,Exercise & Sports, Faculty of Science,University of Copenhagen,DK-1958 Frederiksberg C,Denmark.
authors.forename: Laurine B S
authors.initials: LB
authors.lastname: Harsløf
authors.affiliation: 2Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences,University of Copenhagen,DK-1958 Frederiksberg C,Denmark.
authors.forename: Anders D
authors.initials: AD
authors.lastname: Andersen
authors.affiliation: 3Department of Systems Biology,Center for Biological Sequence Analysis,Technical University of Denmark,2800 Lyngby,Denmark.
authors.forename: Lars I
authors.initials: LI
authors.lastname: Hellgren
authors.affiliation: 1Department of Nutrition,Exercise & Sports, Faculty of Science,University of Copenhagen,DK-1958 Frederiksberg C,Denmark.
authors.forename: Kim F
authors.initials: KF
authors.lastname: Michaelsen
authors.affiliation: 1Department of Nutrition,Exercise & Sports, Faculty of Science,University of Copenhagen,DK-1958 Frederiksberg C,Denmark.
authors.forename: Lotte
authors.initials: L
authors.lastname: Lauritzen
mesh_terms: D015992:Body Mass Index; D003430:Cross-Sectional Studies; D003718:Denmark; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D002149:Energy Intake; D005260:Female; D005395:Fish Oils / Q000008:administration & dosage*; D006801:Humans; D007223:Infant; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D010938:Plant Oils / Q000008:administration & dosage; D012737:Sex Factors; D000074242:Sunflower Oil; D044465:White People
chemical_list: D005395:Fish Oils; C583557:IGF1 protein, human; C515497:IGFBP3 protein, human; D018972:Insulin-Like Growth Factor Binding Protein 3; D010938:Plant Oils; D000074242:Sunflower Oil; D007334:Insulin-Like Growth Factor I
keywords: Children; FO fish oil; Growth; IGF-1 insulin-like growth factor-1; IGFBP-3 IGF-1 and its binding protein-3; Obesity; PUFA; SO sunflower oil; Sex differences; n-3 LCPUFA 
                    n-3 long-chain PUFA