title: Aerobic fitness does not modify the effect of FTO variation on body composition traits.
abstract: OBJECTIVE
  Poor physical fitness and obesity are risk factors for all cause morbidity and mortality. We aimed to clarify whether common genetic variants of key energy intake determinants in leptin (LEP), leptin receptor (LEPR), and fat mass and obesity-associated (FTO) are associated with aerobic and neuromuscular performance, and whether aerobic fitness can alter the effect of these genotypes on body composition.
  
  
  METHODS
  846 healthy Finnish males of Caucasian origin were genotyped for FTO (rs8050136), LEP (rs7799039) and LEPR (rs8179183 and rs1137101) single nucleotide polymorphisms (SNPs), and studied for associations with maximal oxygen consumption, body fat percent, serum leptin levels, waist circumference and maximal force of leg extensor muscles.
  
  
  RESULTS
  Genotype AA of the FTO SNP rs8050136 associated with higher BMI and greater waist circumference compared to the genotype CC. In general linear model, no significant interaction for FTO genotype-relative VO(2)max (mL·kg(-1)·min(-1)) or FTO genotype-absolute VO(2)max (L·min(-1)) on BMI or waist circumference was found. Main effects of aerobic performance on body composition traits were significant (p<0.001). Logistic regression modelling found no significant interaction between aerobic fitness and FTO genotype. LEP SNP rs7799039, LEPR SNPs rs8179183 and rs1137101 did not associate with any of the measured variables, and no significant interactions of LEP or LEPR genotype with aerobic fitness were observed. In addition, none of the studied SNPs associated with aerobic or neuromuscular performance.
  
  
  CONCLUSIONS
  Aerobic fitness may not modify the effect of FTO variation on body composition traits. However, relative aerobic capacity associates with lower BMI and waist circumference regardless of the FTO genotype. FTO, LEP and LEPR genotypes unlikely associate with physical performance.
authors.affiliation: Institute of Biomedicine, Physiology, University of Eastern Finland, Kuopio, Finland. antti.huuskonen@fimnet.fi
authors.forename: Antti
authors.initials: A
authors.lastname: Huuskonen
authors.forename: Jani
authors.initials: J
authors.lastname: Lappalainen
authors.forename: Niku
authors.initials: N
authors.lastname: Oksala
authors.forename: Matti
authors.initials: M
authors.lastname: Santtila
authors.forename: Keijo
authors.initials: K
authors.lastname: Häkkinen
authors.forename: Heikki
authors.initials: H
authors.lastname: Kyröläinen
authors.forename: Mustafa
authors.initials: M
authors.lastname: Atalay
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D000328:Adult; D000071516:Alpha-Ketoglutarate-Dependent Dioxygenase FTO; D001823:Body Composition; D015992:Body Mass Index; D015444:Exercise / Q000502:physiology*; D006801:Humans; D020738:Leptin / Q000097:blood / Q000235:genetics*; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D010101:Oxygen Consumption / Q000235:genetics; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011506:Proteins / Q000235:genetics*; D054411:Receptors, Leptin / Q000097:blood / Q000235:genetics*; D055105:Waist Circumference
chemical_list: D020738:Leptin; D011506:Proteins; D054411:Receptors, Leptin; D000071516:Alpha-Ketoglutarate-Dependent Dioxygenase FTO; C526492:FTO protein, human