title: Walking four times weekly for at least 15 min is associated with longevity in a cohort of very elderly people.
abstract: OBJECTIVE
  This study investigated the role of walking outdoors on longevity, controlling for individual and other life-style factors as possible confounders.
  
  
  METHODS
  A 10-year cohort study was conducted with 152 self-caring and mobile, mean age 80 years, were enrolled in the study. Information on socio-demographic characteristics, clinical and biochemical data, diet, physical activity, smoking, depression status, cognitive status and anthropometrics measurements, were obtained for all participants. Cox proportional-hazards models were used to determine independent predictors of longevity.
  
  
  RESULTS
  During the 10-years of follow-up, 96 (63%) died. Old age, chronic diseases, smoking, depression, CD4/CD8 ratio and coffee consumption were significantly predictors of mortality. Over-all survival was highest for subjects walking at open air for 4 times weekly for at least 15 min in comparison to subjects walking less than 4 times weekly (40% versus 22%). After adjusting for sex, age, education, chronic diseases, smoking, Body Mass Index and CD4/CD8 ratio, elderly people walking at open air for four times weekly had 40% decreased risk of mortality that individuals who walked less than four times weekly [relative risk (RR)=0.53; 95% confidence interval (CI)=0.32-0.88, p=0.01].
  
  
  CONCLUSIONS
  Findings suggest an independent and protective effect of walking on mortality and supports the encouragement of physical activity in advanced age for increasing longevity.
authors.affiliation: Clinical Epidemiology Unit, IDI-IRCSS, Rome, Italy. Electronic address: c.fortes@idi.it.
authors.forename: Cristina
authors.initials: C
authors.lastname: Fortes
authors.affiliation: Clinical Epidemiology Unit, IDI-IRCSS, Rome, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Mastroeni
authors.affiliation: Agency for Public Health of Lazio Region, Rome, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Sperati
authors.affiliation: National Institute of Health, Rome, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Pacifici
authors.affiliation: National Institute of Health, Rome, Italy.
authors.forename: PierGiorgio
authors.initials: P
authors.lastname: Zuccaro
authors.affiliation: Department of Epidemiology, Regional Health Service, Lazio, Italy.
authors.forename: Forastiere
authors.initials: F
authors.lastname: Francesco
authors.affiliation: Department of Epidemiology, Regional Health Service, Lazio, Italy.
authors.forename: Nerina
authors.initials: N
authors.lastname: Agabiti
authors.affiliation: Department of Epidemiology, Regional Health Service, Lazio, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Piras
authors.affiliation: National Research Institute for research on food and Nutrition, INRAN, Italy.
authors.forename: D'Amicis
authors.initials: D
authors.lastname: Amleto
authors.affiliation: Department of NonCommunicable Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: Shah
authors.initials: S
authors.lastname: Ebrahim
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D016516:CD4-CD8 Ratio; D002908:Chronic Disease; D003069:Coffee; D003071:Cognition / Q000502:physiology; D015331:Cohort Studies; D003863:Depression / Q000523:psychology; D005247:Feeding Behavior; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008019:Life Style; D008136:Longevity; D008137:Longitudinal Studies; D008297:Male; D009043:Motor Activity; D016016:Proportional Hazards Models; D012307:Risk Factors; D012907:Smoking; D015996:Survival Rate; D016138:Walking / Q000502:physiology*
chemical_list: D003069:Coffee
keywords: Elderly; Immunity; Life-style; Longevity; Walking