Objectives: To examine relationships between modifiable midlife factors, aging, and physical and cognitive function (independent aging) and survival in very old age.
Design: Prospective cohort.
Setting: Uppsala Longitudinal Study of Adult Men, Uppsala, Sweden.
Participants: Swedish men investigated in 1970-74 (aged 48.6-51.1) and followed up for four decades (N=2,293).
Measurements: Conventional cardiovascular risk factors, body mass index (BMI), and dietary biomarkers were measured, and a questionnaire was used to gather information on lifestyle variables at age 50. Four hundred seventy-two men were reinvestigated in 2008-09 (aged 84.8-88.9). Independent aging was defined as survival to age 85, Mini-Mental State Examination score of 25 or greater, not living in an institution, independent in personal care and hygiene, able to walk outdoors without personal help, and no diagnosis of dementia. The National Swedish Death Registry provided survival data.
Results: Thirty-eight percent of the cohort survived to age 85. Seventy-four percent of the participants in 2008-09 were aging independently. In univariable analyses, high leisure-time physical activity predicted survival but not independent aging. Low work-time physical activity was associated more strongly with independent aging (odds ratio (OR)=1.84, 95% confidence interval (CI)=1.18-2.88) than with survival (OR=1.27, 95% CI=1.05-1.52). In multivariable analyses, midlife BMI was negatively associated (OR=0.80/SD, 95% CI=0.65-0.99/SD), and never or former smoking was positively associated (OR=1.66, 95% CI=1.07-2.59), with independent aging. As expected, conventional cardiovascular and lifestyle risk factors were associated with mortality.
Conclusion: A normal midlife BMI and not smoking were associated with independent aging close to four decades later, indicating that normal weight at midlife has the potential not only to increase survival, but also to preserve independence with aging.
Keywords: independent aging; longitudinal; obesity; smoking; successful aging.
© 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society.