title: Objectively measured physical activity and inflammatory cytokine levels in middle-aged Japanese people.
abstract: OBJECTIVE
  Studies using self-reported physical activity (PA) showed that higher PA is associated with lower circulating levels of C-reactive protein; in contrast, studies investigating associations of objective PA and other inflammatory markers are limited. We investigated cross-sectional associations of accelerometer-determined PA with circulating levels of myokine-type inflammatory cytokines in a middle-aged Japanese population.
  
  
  METHODS
  A total of 1838 individuals (737 men and 1101 women) aged 40 to 69 years participated in the baseline survey of a population-based cohort study in Saga, Japan (2005-2007). Habitual PA was assessed by a single-axis accelerometer. Serum interleukin (IL)-4, IL-6, IL-8, IL-15, and tumor necrosis factor (TNF)-α were measured by a multiplex enzyme-linked immunosorbent assay. Associations between PA and cytokine levels were assessed by multiple regression analysis and analysis of covariance, with adjustment for potential confounders.
  
  
  RESULTS
  Step count and PA level (PAL) were inversely associated with TNF-α and IL-15 even after adjusting for BMI. Similarly, greater PA indices were also independently associated with a lower level of inflammatory cytokine z score as an index of overall inflammation.
  
  
  CONCLUSIONS
  The current results suggest that greater engagement in daily PA may be linked with reduced levels of myokine-type cytokines including IL-15, irrespective of body weight in middle-aged Japanese people.
authors.affiliation: Department of Preventive Medicine, Faculty of Medicine, Saga University, Nabeshima 5-1-1, Saga 849-8501, Japan. Electronic address: ynishida@cc.saga-u.ac.jp.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Nishida
authors.affiliation: Laboratory of Exercise Physiology, Faculty of Sports and Health Science, Fukuoka University, Nanakuma 8-19-1, Fukuoka 814-0180, Japan.
authors.forename: Yasuki
authors.initials: Y
authors.lastname: Higaki
authors.affiliation: Department of Preventive Medicine, Faculty of Medicine, Saga University, Nabeshima 5-1-1, Saga 849-8501, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Taguchi
authors.affiliation: Department of Preventive Medicine, Faculty of Medicine, Saga University, Nabeshima 5-1-1, Saga 849-8501, Japan.
authors.forename: Megumi
authors.initials: M
authors.lastname: Hara
authors.affiliation: St. Mary's College Faculty of Nursing, Tsubuku-honmachi 422, Kurume 830-8558, Japan.
authors.forename: Kazuyo
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Department of Preventive Medicine, Faculty of Medicine, Saga University, Nabeshima 5-1-1, Saga 849-8501, Japan.
authors.forename: Hinako
authors.initials: H
authors.lastname: Nanri
authors.affiliation: Department of Preventive Medicine, Faculty of Medicine, Saga University, Nabeshima 5-1-1, Saga 849-8501, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Imaizumi
authors.affiliation: Research Planning and Information Science Division, Department of Management, Fukuoka Institute of Health and Environmental Sciences, Shirakibaru 3-5-25, Onojo 816-0943, Japan.
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Sakamoto
authors.affiliation: Department of Preventive Medicine, Faculty of Medicine, Saga University, Nabeshima 5-1-1, Saga 849-8501, Japan.
authors.forename: Mikako
authors.initials: M
authors.lastname: Horita
authors.affiliation: Division of International Health and Nursing, Faculty of Medicine, Saga University, Nabeshima 5-1-1, Saga 849-8501, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Shinchi
authors.affiliation: Department of Preventive Medicine, Faculty of Medicine, Saga University, Nabeshima 5-1-1, Saga 849-8501, Japan.
authors.forename: Keitaro
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D061725:Accelerometry / Q000295:instrumentation / Q000379:methods; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D016207:Cytokines / Q000032:analysis*; D005260:Female; D006304:Health Status; D006801:Humans; D007249:Inflammation / Q000097:blood*; D007378:Interleukins / Q000097:blood; D007564:Japan; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods; D009043:Motor Activity / Q000502:physiology*; D012907:Smoking; D011795:Surveys and Questionnaires; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D015415:Biomarkers; D016207:Cytokines; D007378:Interleukins; D014409:Tumor Necrosis Factor-alpha
keywords: Accelerometry; Exercise; Inflammation; Interleukins