title: Polymorphisms in the CNTF and CNTF receptor genes are associated with muscle strength in men and women.
abstract: Genotypic associations between polymorphisms in the ciliary neurotrophic factor (CNTF) and CNTF receptor (CNTFR) genes and muscular strength phenotypes in 154 middle-aged men (45-49 yr) and 138 women (38-44 yr) and 99 older men (60-78 yr) and 102 older women (60-80 yr) were tested to validate earlier association studies. Allelic interaction effects were hypothesized between alleles of CNTF and CNTFR. We performed analysis of covariance with age, height, and fat-free mass (FFM) as covariates. FFM was anthropometrically estimated by the equation of Durnin-Womersley. Isometric, concentric, and eccentric torques for the knee flexors (KF) and extensors (KE) were measured using Biodex dynamometry. In the older male group, T-allele carriers of the C-1703T polymorphism in CNTFR performed significantly better on all noncorrected KF torques, whereas only noncorrected KE isometric torque at 120 degrees and concentric torque at 240 degrees/s were higher than the C/C homozygotes (P < 0.05). When age, height, and FFM were used as covariates, T-allele carriers performed only better on KE and KF isometric torque at 120 degrees (P < 0.05). Concentric KF torque at 180 degrees/s was lower in middle-aged female A-allele carriers compared with the T/T subjects for the T1069A polymorphism in CNTFR. After correction for age, height, and FFM, middle-aged female A-allele carriers exhibited lower values on all concentric KF strength measures and isometric torque at 120 degrees . There was a lack of association with the CNTF G-6A polymorphism in men, with inconclusive results for a limited number of phenotypes in women. No significant CNTF/CNTFR allele interaction effects were found. Results indicate that CNTFR C-1703T and T1069A polymorphisms are significantly associated with muscle strength in humans.
authors.affiliation: Dept. of Biomedical Kinesiology, Research Center for Exercise and Health, Faculty of Kinesiology and Rehabilitation Sciences, Katholieke Universiteit Leuven, B-3001 Leuven, Belgium.
authors.forename: Gunther
authors.initials: G
authors.lastname: De Mars
authors.forename: An
authors.initials: A
authors.lastname: Windelinckx
authors.forename: Gaston
authors.initials: G
authors.lastname: Beunen
authors.forename: Christophe
authors.initials: C
authors.lastname: Delecluse
authors.forename: Johan
authors.initials: J
authors.lastname: Lefevre
authors.forename: Martine A I
authors.initials: MA
authors.lastname: Thomis
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000235:genetics*; D020934:Ciliary Neurotrophic Factor / Q000235:genetics*; D015331:Cohort Studies; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D007717:Knee; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000235:genetics / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D010641:Phenotype; D020801:Receptor, Ciliary Neurotrophic Factor / Q000235:genetics*; D012737:Sex Factors; D019415:Torque
chemical_list: D020934:Ciliary Neurotrophic Factor; D020801:Receptor, Ciliary Neurotrophic Factor