title: Relationships between contraction properties of knee extensor muscles and fasting IGF-1 and adipocytokines in physically active postmenopausal women.
abstract: The aim of this cross-sectional study was to find possible relationships between insulin-like growth factor-1 (IGF-1), adipocytokines (leptin and adiponectin) and twitch contraction (TC) characteristics of the knee extensor (KE) muscles in healthy physically active postmenopausal women (n = 28, 64-78 years old). We hypothesized that IGF-1 is related at least to isometric TC peak torque (Pt) as the highest value of isometric torque production and maximal voluntary contraction (MVC) torque, and there will not be any relationships between TC characteristics and leptin and adiponectin. During the measurement of MVC torque and twitch contractile properties of KE muscles, the subjects sat in a custom-made dynamometric chair with the knee and hip angles equal to 90 degrees and 100 degrees, respectively. To assess the contractile properties of the KE muscles, electrically evoked isometric twitch was elicited by percutaneous electrical nerve stimulation. Serum leptin, adiponectin, IGF-1, insulin-like growth factor-binding protein-3 (IGFBP-3) and insulin were determined. There were a very few significant relationships between the measured muscle contractile parameters and fasting blood hormones. TC Pt correlated significantly with IGFBP-3 (r = 0.652, P = 0.001) and insulin (r = 0.495, P = 0.007). In conclusion, this study suggests that only TC peak torque correlated positively with serum fasting IGFBP-3 and insulin concentration. Adipocytokines leptin and adiponectin not correlated significantly with measured strength parameters in physically active postmenopausal women.
authors.affiliation: Institute of Sport Pedagogy and Coaching Sciences, Faculty of Exercise and Sport Sciences, Centre of Behavioural and Health Science, University of Tartu.
authors.forename: Toivo
authors.initials: T
authors.lastname: Jürimäe
authors.affiliation: Institute of Exercise Biology and Physiotherapy, Faculty of Exercise and Sport Sciences, Centre of Behavioural and Health Science, University of Tartu, Tartu, Estonia.
authors.forename: Mati
authors.initials: M
authors.lastname: Pääsuke
authors.affiliation: Institute of Exercise Biology and Physiotherapy, Faculty of Exercise and Sport Sciences, Centre of Behavioural and Health Science, University of Tartu, Tartu, Estonia.
authors.forename: Tatjana
authors.initials: T
authors.lastname: Kums
authors.affiliation: Institute of Exercise Biology and Physiotherapy, Faculty of Exercise and Sport Sciences, Centre of Behavioural and Health Science, University of Tartu, Tartu, Estonia.
authors.forename: Helena
authors.initials: H
authors.lastname: Gapeyeva
authors.affiliation: Institute of Exercise Biology and Physiotherapy, Faculty of Exercise and Sport Sciences, Centre of Behavioural and Health Science, University of Tartu, Tartu, Estonia.
authors.forename: Jaan
authors.initials: J
authors.lastname: Ereline
authors.affiliation: Institute of Sport Pedagogy and Coaching Sciences, Faculty of Exercise and Sport Sciences, Centre of Behavioural and Health Science, University of Tartu.
authors.forename: Meeli
authors.initials: M
authors.lastname: Saar
authors.affiliation: Institute of Sport Pedagogy and Coaching Sciences, Faculty of Exercise and Sport Sciences, Centre of Behavioural and Health Science, University of Tartu.
authors.forename: Jaak
authors.initials: J
authors.lastname: Jürimäe
mesh_terms: D054392:Adipokines / Q000097:blood*; D052242:Adiponectin / Q000097:blood; D000368:Aged; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D004558:Electric Stimulation; D004957:Estonia; D005215:Fasting / Q000097:blood*; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D018972:Insulin-Like Growth Factor Binding Protein 3; D018969:Insulin-Like Growth Factor Binding Proteins / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D007537:Isometric Contraction; D007717:Knee; D020738:Leptin / Q000097:blood; D008875:Middle Aged; D053580:Muscle Strength; D053581:Muscle Strength Dynamometer; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology*; D010809:Physical Fitness; D017698:Postmenopause; D019415:Torque
chemical_list: C499918:ADIPOQ protein, human; D054392:Adipokines; D052242:Adiponectin; D015415:Biomarkers; C515497:IGFBP3 protein, human; D007328:Insulin; D018972:Insulin-Like Growth Factor Binding Protein 3; D018969:Insulin-Like Growth Factor Binding Proteins; D020738:Leptin; D007334:Insulin-Like Growth Factor I