title: The association of grip strength from midlife onwards with all-cause and cause-specific mortality over 17 years of follow-up in the Tromsø Study.
abstract: BACKGROUND
  Grip strength has consistently been found to predict all-cause mortality rates. However, few studies have examined cause-specific mortality or tested age differences in these associations.
  
  
  METHODS
  In 1994, grip strength was measured in the population-based Tromsø Study, covering the ages 50-80 years (N=6850). Grip strength was categorised into fifths, and as z-scores. In this cohort study, models with all-cause mortality and deaths from specific causes as the outcome were performed, stratified by sex and age using Cox regression, adjusting for lifestyle-related and health-related factors.
  
  
  RESULTS
  During 17 years of follow-up, 2338 participants died. A 1 SD reduction in grip strength was associated with HR=1.17 (95% CI 1.12 to 1.22) for all-cause mortality in a model adjusted for age, gender and body size. This association was similar across all age groups, in men and women, and robust to adjustment for a range of lifestyle-related and health-related factors. Results for deaths due to cardiovascular disease (CVD), respiratory diseases and external causes resembled those for all-cause mortality, while for cancer, the association was much weaker and not significant after adjustment for lifestyle-related and health-related factors.
  
  
  CONCLUSIONS
  Weaker grip strength was associated with increased all-cause mortality rates, with similar effects on deaths due to CVD, respiratory disease and external causes, while a much weaker association was observed for cancer-related deaths. These associations were similar in both genders and across age groups, which supports the hypothesis that grip strength might be a biomarker of ageing over the lifespan.
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway.|Institute of Health and Society, University of Oslo, Oslo, Norway.|Norwegian National Advisory Unit on Ageing and Health, Vestfold Hospital Trust, Tønsberg, Norway.|Department of Geriatric Medicine, Oslo University Hospital, Oslo, Norway.
authors.forename: Bjørn Heine
authors.initials: BH
authors.lastname: Strand
authors.affiliation: MRC Unit for Lifelong Health and Ageing, University College London (UCL), London, UK.
authors.forename: Rachel
authors.identifier: http://orcid.org/0000-0003-3370-5720
authors.initials: R
authors.lastname: Cooper
authors.affiliation: Oslo and Akershus University College, Oslo, Norway.
authors.forename: Astrid
authors.initials: A
authors.lastname: Bergland
authors.affiliation: Department of Health and Care Sciences, UiT The Arctic University of Norway, Tromsø, Norway.|Department of Clinical Therapeutic Services, University Hospital of North Norway, Tromsø, Norway.
authors.forename: Lone
authors.initials: L
authors.lastname: Jørgensen
authors.affiliation: Department of Clinical Medicine, Faculty of Health sciences, The Arctic University of Norway, Tromsø, Norway.|Division of Cardiothoracic and Respiratory Medicine, University Hospital of North Norway, Tromsø, Norway.
authors.forename: Henrik
authors.initials: H
authors.lastname: Schirmer
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Vegard
authors.initials: V
authors.lastname: Skirbekk
authors.affiliation: Department of Health and Care Sciences, UiT The Arctic University of Norway, Tromsø, Norway.
authors.forename: Nina
authors.initials: N
authors.lastname: Emaus
keywords: Epidemiology of ageing; LONGITUDINAL STUDIES; MORTALITY; PHYSICAL FUNCTION