title: Biomarkers associated with sedentary behaviour in older adults: A systematic review.
abstract: OBJECTIVE
  Pathomechanisms of sedentary behaviour (SB) are unclear. We conducted a systematic review to investigate the associations between SB and various biomarkers in older adults.
  
  
  METHODS
  Electronic databases were searched (MEDLINE, EMBASE, CINAHL, AMED) up to July 2015 to identify studies with objective or subjective measures of SB, sample size ≥50, mean age ≥60years and accelerometer wear time ≥3days. Methodological quality was appraised with the CASP tool. The protocol was pre-specified (PROSPERO CRD42015023731).
  
  
  RESULTS
  12701 abstracts were retrieved, 275 full text articles further explored, from which 249 were excluded. In the final sample (26 articles) a total of 63 biomarkers were detected. Most investigated markers were: body mass index (BMI, n=15), waist circumference (WC, n=15), blood pressure (n=11), triglycerides (n=12) and high density lipoprotein (HDL, n=15). Some inflammation markers were identified such as interleukin-6, C-reactive protein or tumor necrosis factor alpha. There was a lack of renal, muscle or bone biomarkers. Randomized controlled trials found a positive correlation for SB with BMI, neck circumference, fat mass, HbA1C, cholesterol and insulin levels, cohort studies additionally for WC, leptin, C-peptide, ApoA1 and Low density lipoprotein and a negative correlation for HDL.
  
  
  CONCLUSIONS
  Most studied biomarkers associated with SB were of cardiovascular or metabolic origin. There is a suggestion of a negative impact of SB on biomarkers but still a paucity of high quality investigations exist. Longitudinal studies with objectively measured SB are needed to further elucidate the pathophysiological pathways and possible associations of unexplored biomarkers.
authors.affiliation: Agaplesion Bethesda Hospital, Geriatric Medicine Ulm University, Ulm, Germany; Geriatric Center Ulm/Alb-Donau, Ulm, Germany; Department of Epidemiology and Medical Biometry, Ulm University, Ulm, Germany. Electronic address: katharina.wirth@bethesda-ulm.de.
authors.forename: Katharina
authors.initials: K
authors.lastname: Wirth
authors.affiliation: Department of Epidemiology and Medical Biometry, Ulm University, Ulm, Germany; Department of Clinical Gerontology, Robert-Bosch-Hospital, Stuttgart, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Klenk
authors.affiliation: Agaplesion Bethesda Hospital, Geriatric Medicine Ulm University, Ulm, Germany; Geriatric Center Ulm/Alb-Donau, Ulm, Germany.
authors.forename: Simone
authors.initials: S
authors.lastname: Brefka
authors.affiliation: Agaplesion Bethesda Hospital, Geriatric Medicine Ulm University, Ulm, Germany; Geriatric Center Ulm/Alb-Donau, Ulm, Germany.
authors.forename: Dhayana
authors.initials: D
authors.lastname: Dallmeier
authors.affiliation: Agaplesion Bethesda Hospital, Geriatric Medicine Ulm University, Ulm, Germany; Geriatric Center Ulm/Alb-Donau, Ulm, Germany; Department of Epidemiology and Medical Biometry, Ulm University, Ulm, Germany.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Faehling
authors.affiliation: Fundació Salut i Envelliment - Universitat Autònoma de Barcelona, Biomedical Research Institute Sant Pau (IIB-Sant Pau), Barcelona, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Roqué I Figuls
authors.affiliation: UKCRC Centre of Excellence for Public Health (NI), Centre for Public Health, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, United Kingdom.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Tully
authors.affiliation: Faculty of Psychology, Education and Sport Sciences Blanquerna, Ramon Llull University, Barcelona, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Giné-Garriga
authors.affiliation: Department of Sports Science and Clinical Biomechanics, SDU Muscle Research Cluster (SMRC), University of Southern Denmark, Odense, Denmark; National Institutes of Health, National Institute on Aging, Laboratory of Epidemiology and Population Sciences (LPES), Bethesda, MD, USA.
authors.forename: Paolo
authors.initials: P
authors.lastname: Caserotti
authors.affiliation: Fundació Salut i Envelliment - Universitat Autònoma de Barcelona, Biomedical Research Institute Sant Pau (IIB-Sant Pau), Barcelona, Spain.
authors.forename: Antoni
authors.initials: A
authors.lastname: Salvà
authors.affiliation: Department of Epidemiology and Medical Biometry, Ulm University, Ulm, Germany.
authors.forename: Dietrich
authors.initials: D
authors.lastname: Rothenbacher
authors.affiliation: Agaplesion Bethesda Hospital, Geriatric Medicine Ulm University, Ulm, Germany; Geriatric Center Ulm/Alb-Donau, Ulm, Germany; Department of Epidemiology and Medical Biometry, Ulm University, Ulm, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Denkinger
authors.affiliation: Physiotherapy Department, South London and Maudsley NHS Foundation Trust, Denmark Hill, London SE5 8AZ, United Kingdom; Health Service and Population Research Department, Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespigny Park, London, Box SE5 8AF, United Kingdom; Faculty of Health, Social Care and Education, Anglia Ruskin University, Chelmsford, United Kingdom.
authors.forename: Brendon
authors.initials: B
authors.lastname: Stubbs
mesh_terms: D015415:Biomarkers / Q000032:analysis / Q000097:blood; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000378:metabolism; D002784:Cholesterol / Q000097:blood*; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D007328:Insulin / Q000097:blood*; D008875:Middle Aged; D012307:Risk Factors; D057185:Sedentary Behavior; D013223:Statistics as Topic
chemical_list: D015415:Biomarkers; D002784:Cholesterol; D006442:Glycated Hemoglobin; D007328:Insulin
keywords: Biomarker; Older adults; Sedentary behaviour