Purpose: Stressful life events have been reported to influence physical function and the risk of disease in elderly people. However, few studies have examined the relationship between stressful events and habitual physical activity, an important factor influencing health status in the elderly. The purpose of the current study was thus to investigate relationships between selected life events and yearlong objective assessments of the quantity and quality of physical activity in older individuals.
Methods: The subjects were free-living healthy Japanese (83 males aged 73 ± 5 years and 101 females aged 72 ± 4 years). All gave their written informed consent to participate in this institutionally approved study, after the protocol, stresses, and possible risks had been fully described to them. An electronic uniaxial pedometer/accelerometer was attached to the individual’s waist belt. Data were recorded on a 24-hr basis for an entire year. After inspection for periods of inappropriate recording, 1-year averages were computed for daily step count and the daily duration of exercise at an intensity >3 metabolic equivalents (METs). At the end of the year, subjects responded to an 8-item questionnaire about the number of stressful life events such as retirement or death of a partner during the preceding year and their perceived severities. After controlling for age, we calculated Pearson’s partial correlation coefficients between these events (number and self-reported severity) and our measurements of habitual physical activity (daily step count and duration of activity >3 METs).
Results: The most severe life events were seen as the partner’s death (in both men and women) and retirement (in male subjects). After controlling for age, the number of life events showed significant negative correlations with both daily step count and the daily duration of physical activity >3 METs in males (r = -.27, p = .02; r = -.37, p = .001, respectively); females showed a similar trend, but this was not statistically significant (r = -.17, p = .09; r = -.16, p = .11, respectively). Again controlling for age, the self-reported total severity of life events had significant negative correlation coefficients with both total step count and the duration of exercise >3 METs, both in males (r = -.29, p = .01; r = -.37, p = .001, respectively) and in females (r = -.21, p = .03; r = -.25, p = .01, respectively).
Conclusion: Stressful life events seem more closely associated with a decrease of habitual physical activity in men than in women. This may reflect in part the fact that mortality after the hospitalization of a spouse is higher in men than in women.