title: Natural history of leisure-time physical activity and its correlates: associations with mortality from all causes and cardiovascular disease over 28 years.
abstract: The association between leisure-time physical activity and 28-year (1965-1993) risk of death from all causes and cardiovascular disease was studied in 6,131 adults who participated in the Alameda County Study in Northern California. Because study participants were interviewed on a number of occasions, it was possible to include in the analyses information on changes over time in levels of leisure-time physical activity as well as changes in a wide variety of other risk factors. There were 47,616 person-years of observation for males (639 deaths from all causes and 321 from cardiovascular disease) and 57,666 person-years of observation for females (587 deaths from all causes and 388 from cardiovascular disease). In analyses in which only the baseline values of all covariates were included, a four-point increase on the leisure-time physical activity scale, the interquartile range, was associated with reduced risk of death from all causes (relative risk (RR) = 0.90, 95% confidence interval (CI) 0.83-0.99) and cardiovascular disease (RR = 0.85, 95% CI 0.75-0.97). When time-varying information on leisure-time physical activity and all other covariates was included, there was still a protective effect for all-cause and cardiovascular disease mortality (RR = 0.84, 95% CI 0.77-0.92 and RR = 0.81, 95% CI 0.71-0.93, respectively). The association between leisure-time physical activity and risk of death was not altered when information on variations over time in leisure-time physical activity and many determinants and consequences of physical activity were explicitly included in survival models.
authors.affiliation: Human Population Laboratory, California Department of Health Services, Berkeley 94704-1011, USA.
authors.forename: G A
authors.initials: GA
authors.lastname: Kaplan
authors.forename: W J
authors.initials: WJ
authors.lastname: Strawbridge
authors.forename: R D
authors.initials: RD
authors.lastname: Cohen
authors.forename: L R
authors.initials: LR
authors.lastname: Hungerford
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002140:California; D002318:Cardiovascular Diseases / Q000401:mortality; D004812:Epidemiologic Methods; D015444:Exercise; D005260:Female; D006304:Health Status; D006801:Humans; D007899:Leisure Activities; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009026:Mortality; D012306:Risk