Perceived stress symptoms in midlife predict disability in old age: a 28-year prospective cohort study.
BACKGROUND
Stress has damaging effects on individual's health. However, information about the long-term consequences of mental stress is scarce.


METHODS
This 28-year prospective cohort study examined on the associations between midlife stress and old age disability among 2,994 Finnish municipal professionals aged 44-58 years at baseline. Self-reported stress symptoms were assessed at baseline in 1981 and 4 years later in 1985 and perceived disability in 2009. For the baseline data, principal component analysis was used for differentiation into stress symptom profiles. The regression coefficient estimates for self-care disability (activities of daily living) and instrumental activities of daily living disability were estimated using left-censored regression. The odds ratios for mobility limitation were estimated using logistic regression.


RESULTS
Four midlife stress profiles were identified: negative reactions to work and depressiveness, perceived decrease in cognition, sleep disturbances, and somatic symptoms. We saw a clear gradient of increasing disability severity in old age for increasing intensity of midlife stress symptoms. In comparison with the participants with no stress symptoms, the extensively adjusted left-censored and logistic regression models showed that in old age, disability scores were almost 2-4 units higher and risk for mobility limitation was 2-3 times higher for those with constant stress symptoms in midlife.


CONCLUSIONS
Among occupationally active 44- to 58-year-old men and women, perceived stress symptoms in midlife correlated with disability 28 years later. Stress symptoms may be the first signs of decompensation of individual functioning relative to environmental demands, which may later manifest in disabilities.
Gerontology Research Center and Department of Health Sciences, University of Jyväskylä, P.O. Box 35, FIN - 40014, Jyväskylä, Finland. jenni.kulmala@jyu.fi
Jenni
J
Kulmala
Mikaela B
MB
von Bonsdorff
Sari
S
Stenholm
Timo
T
Törmäkangas
Monika E
ME
von Bonsdorff
Clas-Håkan
CH
Nygård
Matti
M
Klockars
Jorma
J
Seitsamo
Juhani
J
Ilmarinen
Taina
T
Rantanen
D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology* / Q000523:psychology*; D015331:Cohort Studies; D006233:Persons with Disabilities; D005260:Female; D005387:Finland; D006801:Humans; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D011446:Prospective Studies; D012307:Risk Factors; D013315:Stress, Psychological / Q000503:physiopathology*
Disablement process; Epidemiology; Functional performance; Psychosocial stress; Public health