title: Life-long endurance exercise in humans: circulating levels of inflammatory markers and leg muscle size.
abstract: Human aging is associated with a loss of skeletal muscle and an increase in circulating inflammatory markers. It is unknown whether endurance training (Tr) can prevent these changes. Therefore we studied 15 old trained (O-Tr) healthy males and, for comparison, 12 old untrained (O-Un), 10 Young-Tr (Y-Tr) and 12 Young-Un (Y-Un). Quadriceps size, VO2 peak, CRP, IL-6, TNF-α and its receptors, suPAR, lipid profile, leucocytes and glucose homeostasis were measured. Tr was associated with an improved insulin profile (p<0.05), and lower leucocyte (p<0.05) and triglyceride levels (p<0.05), independent of age. Aging was associated with poorer glucose control (p<0.05), independent of training. The age-related changes in waist circumference, VO2 peak, cholesterol, LDL, leg muscle size, CRP and IL-6 were counteracted by physical activity (p<0.05). A significant increase in suPAR with age was observed (p<0.05). Most importantly, life-long endurance exercise was associated with a lower level of the inflammatory markers CRP and IL-6 (p<0.05), and with a greater thigh muscle area (p<0.05), compared to age-matched untrained counterparts. These findings in a limited group of individuals suggest that regular physical endurance activity may play a role in reducing some markers of systemic inflammation, even within the normal range, and in maintaining muscle mass with aging.
authors.affiliation: Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark. Electronic address: ullaramer@hotmail.com.
authors.forename: U R
authors.initials: UR
authors.lastname: Mikkelsen
authors.affiliation: Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
authors.forename: C
authors.initials: C
authors.lastname: Couppé
authors.affiliation: Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Karlsen
authors.affiliation: CNRS UMR 7338, Biomécanique et Bioingénierie, Université de Technologie de Compiègne, 60205 Compiègne cedex, France; Université Paris 13, Sorbonne Paris Cité, UFR Santé Médecine et Biologie Humaine, 93017 Bobigny, France.
authors.forename: J F
authors.initials: JF
authors.lastname: Grosset
authors.affiliation: Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
authors.forename: P
authors.initials: P
authors.lastname: Schjerling
authors.affiliation: Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
authors.forename: A L
authors.initials: AL
authors.lastname: Mackey
authors.affiliation: Clinical Research Centre, Copenhagen University Hospital, Hvidovre, Denmark.
authors.forename: H H
authors.initials: HH
authors.lastname: Klausen
authors.affiliation: Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
authors.forename: S P
authors.initials: SP
authors.lastname: Magnusson
authors.affiliation: Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Kjær
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D056352:Athletes; D002097:C-Reactive Protein / Q000378:metabolism*; D002784:Cholesterol / Q000378:metabolism; D015444:Exercise; D005947:Glucose / Q000032:analysis; D005951:Glucose Tolerance Test; D006706:Homeostasis; D006801:Humans; D007249:Inflammation; D007328:Insulin / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism*; D007866:Leg / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D018482:Muscle, Skeletal / Q000378:metabolism / Q000502:physiology*; D010101:Oxygen Consumption; D010807:Physical Endurance; D052097:Quadriceps Muscle / Q000502:physiology; D055105:Waist Circumference; D055815:Young Adult
chemical_list: D007328:Insulin; D015850:Interleukin-6; D002097:C-Reactive Protein; D002784:Cholesterol; D005947:Glucose
keywords: Aging; C-reactive protein; CRP; Cytokines; HDL; HOMA-IR; IL-6; IPAQ; International Physical Activity Questionnaire; LDL; Low-grade inflammation; MET; MRI; Master athletes; OGTT; Q-CSA; QUICKI; Skeletal muscle mass; TNF-α; Tr; Un; VO(2) peak; high density lipoprotein; homeostatic model assessment – insulin resistance; interleukin 6; low density lipoprotein; magnetic resonance image; metabolic equivalent of task; oral glucose tolerance test; peak oxygen consumption; quadriceps cross sectional area; quantitative insulin sensitivity check index; sTNFR; soluble TNF receptor; soluble urokinase plasminogen activator receptor; suPAR; trained; tumor necrosis factor alpha; untrained