title: The effect of cognitive-motor dual-task training on cognitive function and plasma amyloid β peptide 42/40 ratio in healthy elderly persons: a randomized controlled trial.
abstract: BACKGROUND
  Physical activity reduces the incidence and progression of cognitive impairment. Cognitive-motor dual-task training, which requires dividing attention between cognitive tasks and exercise, may improve various cognitive domains; therefore, we examined the effect of dual-task training on the executive functions and on plasma amyloid β peptide (Aβ) 42/40 ratio, a potent biomarker of Alzheimer's disease, in healthy elderly people.
  
  
  METHODS
  Twenty-seven sedentary elderly people participated in a 12-week randomized, controlled trial. The subjects assigned to the dual-task training (DT) group underwent a specific cognitive-motor dual-task training, and then the clinical outcomes, including cognitive functions by the Modified Mini-Mental State (3MS) examination and the Trail-Making Test (TMT), and the plasma Aβ 42/40 ratio following the intervention were compared with those of the control single-task training (ST) group by unpaired t-test.
  
  
  RESULTS
  Among 27 participants, 25 completed the study. The total scores in the 3MS examination as well as the muscular strength of quadriceps were equally improved in both groups after the training. The specific cognitive domains, "registration & recall", "attention", "verbal fluency & understanding", and "visuospatial skills" were significantly improved only in the DT group. Higher scores in "attention", "verbal fluency & understanding", and "similarities" were found in the DT group than in the ST group at post-intervention. The absolute changes in the total (8.5 ± 1.6 vs 2.4 ± 0.9, p = 0.004, 95 % confidence interval (CI) 0.75-3.39) and in the scores of "attention" (1.9 ± 0.5 vs -0.2 ± 0.4, p = 0.004, 95 % CI 2.25-9.98) were greater in the DT group than in the ST group. We found no changes in the TMT results in either group. Plasma Aβ 42/40 ratio decreased in both groups following the training (ST group: 0.63 ± 0.13 to 0.16 ± 0.03, p = 0.001; DT group: 0.60 ± 0.12 to 0.25 ± 0.06, p = 0.044), although the pre- and post-intervention values were not different between the groups for either measure.
  
  
  CONCLUSIONS
  Cognitive-motor dual-task training was more beneficial than single-task training alone in improving broader domains of cognitive functions of elderly persons, and the improvement was not directly due to modulating Aβ metabolism.
authors.affiliation: Osaka City University Graduate School of Medicine, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka City, Japan. yokoyama@sports.osaka-cu.ac.jp.
authors.forename: Hisayo
authors.initials: H
authors.lastname: Yokoyama
authors.affiliation: Osaka City University Graduate School of Medicine, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka City, Japan. okazaki@sports.osaka-cu.ac.jp.
authors.forename: Kazunobu
authors.initials: K
authors.lastname: Okazaki
authors.affiliation: Osaka City University Graduate School of Medicine, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka City, Japan. dimai@sports.osaka-cu.ac.jp.
authors.forename: Daiki
authors.initials: D
authors.lastname: Imai
authors.affiliation: Osaka City University Graduate School of Medicine, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka City, Japan. y-yamashina@pt-u.aino.ac.jp.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Yamashina
authors.affiliation: Osaka City University Graduate School of Medicine, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka City, Japan. wind-05@med.osaka-cu.ac.jp.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Takeda
authors.affiliation: Osaka City University Graduate School of Medicine, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka City, Japan. nooshin@med.osaka-cu.ac.jp.
authors.forename: Nooshin
authors.initials: N
authors.lastname: Naghavi
authors.affiliation: Osaka City University Graduate School of Medicine, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka City, Japan. ota@isc.osakac.ac.jp.
authors.forename: Akemi
authors.initials: A
authors.lastname: Ota
authors.affiliation: Osaka City University Graduate School of Medicine, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka City, Japan. yokkunn.h.1124@gmail.com.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Hirasawa
authors.affiliation: Osaka City University Graduate School of Medicine, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka City, Japan. miyagawa@sports.osaka-cu.ac.jp.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Miyagawa
mesh_terms: D000368:Aged; D016229:Amyloid beta-Peptides / Q000097:blood*; D001288:Attention / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D056344:Executive Function / Q000502:physiology*; D015444:Exercise / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D011939:Mental Recall / Q000502:physiology; D010446:Peptide Fragments / Q000097:blood*; D011597:Psychomotor Performance / Q000502:physiology*; D014145:Trail Making Test
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; C538897:amyloid beta-protein (40-42)