Physical activity trajectories, mortality, hospitalization, and disability in the Toledo Study of Healthy Aging

BACKGROUND

Physical activity (PA) is a recognized contributor to healthy aging. However, the majority of studies exploring its associations with adverse outcomes in cohorts of older adults use single-time PA estimates, which do not consider its dynamic nature. The aim of the present study is to explore the presence of different PA trajectories in the Toledo Study of Healthy Aging and their association with adverse outcomes. Our hypothesis is that prospectively maintaining or increasing PA is associated with a reduced risk of adverse outcomes.

METHODS

We used data from 1679 participants enrolled in the Toledo Study of Healthy Aging. Trajectories based on the Physical Activity Scale for the Elderly were identified using group-based trajectory modelling. Cox and logistic regression were used to investigate associations between PA trajectories and mortality and hospitalization, and incident and worsening disability, respectively. Mortality was ascertained by linkage to the Spanish National Death Index; disability was evaluated through the Katz Index; and hospitalization was defined as the first admission to Toledo Hospital. Models were adjusted by age, sex, smoking, Charlson Index, education, cognitive impairment, polypharmacy, and Katz Index at Wave 2.

RESULTS

We found four PA-decreasing and one PA-increasing trajectories: high PA-consistent (n = 566), moderate PA-mildly decreasing (n = 392), low PA-increasing (n = 237), moderate PA-consistent (n = 191), and low PA-decreasing (n = 293). Belonging to the high PA-consistent trajectory group was associated with reduced risks of mortality as compared with the low PA-decreasing group [hazard ratio (HR) 1.68; 95% confidence interval (CI) = 1.21-2.31] and hospitalization compared with the low PA-increasing and low PA-decreasing trajectory groups (HR 1.24; 95% CI = 1.004-1.54 and HR 1.25; 95% CI = 1.01-1.55, respectively) and with lower rates of incident [odds ratio (OR) 3.14; 95% CI = 1.59-6.19] and worsening disability (OR 2.16; 95% CI = 1.35-3.45) in relation to the low PA-decreasing trajectory group and at follow-up. Increasing PA during late life (low PA-increasing group) was associated with lower incident disability rates (OR 0.38; 95% CI = 0.19-0.82) compared with decreasing PA (low PA-decreasing group), despite similar baseline PA.

CONCLUSIONS

Our results suggest that sustaining higher PA levels during aging might lead to healthy aging, characterized by a reduction in adverse outcomes. Our study supports the need for enhancing PA participation among older populations, with the goal of reducing personal and economic burden in a worldwide aging population.

Social participation and risk of influenza infection in older adults: a cross-sectional study

OBJECTIVES

Influenza infection can cause severe pneumonia, which is sometimes fatal, particularly in older adults. Influenza results in 3-5 million cases of severe illness and about 250 000 to 500 000 deaths annually worldwide. Social participation in the context of influenza infection is controversial because, although social participation is beneficial in maintaining physical function and mental health, it also increases the risk of contact with infected people. This study examined the association between social participation and influenza infection in Japanese adults aged 65 years or older.

DESIGN

Cross-sectional study.

SETTING

Japanese functionally independent adults aged 65 years or older.

PARTICIPANTS

Among the respondents to the Japan Gerontological Evaluation Study (JAGES) 2013 survey, which took place during the period from October to December 2013, 12 231 men and 14 091 women responded to questions on influenza vaccination and influenza infection.

OUTCOME MEASURES

Using JAGES data for 12 231 men and 14 091 women aged ≥65 years, we examined the association between social participation and influenza infection. The association between influenza infection and number of groups in which respondents participated was investigated among adults aged≥65 years, stratified by vaccination status and sex.

RESULTS

Unvaccinated women who participated in two or more social activities were 2.20 times (95% CI 1.47 to 3.29) as likely to report an influenza infection as those who reported no social participation. In contrast, vaccinated women who participated in two or more social groups had no additional risk of influenza infection as compared with female elders with no social participation. Among men, participation in social activities was not significantly associated with influenza infection, regardless of vaccination status.

CONCLUSIONS

Social participation was associated with a higher risk of influenza infection among unvaccinated older women, which suggests a need for further efforts to promote influenza vaccination, particularly among socially active elderly women.

Physical activity, fitness, and all-cause mortality: An 18-year follow-up among old people

BACKGROUND

Little is known about change in physical activity (PA) and its relationship to all-cause mortality among old people. There is even less information about the association between PA, fitness, and all-cause mortality among people aged 80 years and above. The objective is to investigate persistence and change in PA over 5 years as a predictor of all-cause mortality, and fitness as a mediator of this association, among people aged 80 and 85 years at the beginning of an 18-year mortality follow-up period.

METHODS

Using Evergreen Project data (started in 1989), 4 study groups were formed according to self-reported changes in PA level, over a 5-year period (starting in 1989-1990 and ending in 1994-1995): remained active (RA, control group), changed to inactive (CI), remained inactive (RI), and changed to active (CA). Mortality was followed up over the 18-year period (1994-2012). Cox models with different covariates such as age, sex, use of alcohol, smoking, chronic diseases, and a 10 m walking test were used to analyze the association between change in PA level and mortality.

RESULTS

Compared to RA, those who decreased their PA level (CI) between baseline and follow-up had higher all-cause mortality (hazard ratio (HR = 2.09; 95%CI: 1.63-2.69) when adjusted for age, gender, and chronic diseases. RI showed the highest all-cause mortality (HR = 2.16; 95%CI: 1.59-2.93). In CA, when compared against RA, the risk of all-cause mortality was not statistically significant (HR = 1.51; 95%CI: 0.95-2.38). In comparison with RA, when walking speed over 10 m was added as a covariate, all-cause mortality risk was almost statistically significant only in CI (HR = 1.37; 95%CI: 1.00-1.87).

CONCLUSION

Persistence and change in PA level was associated with mortality. This association was largely explained by fitness status. Randomized controlled studies are needed to test whether maintaining or increasing PA level could lengthen the life of old people.

The Association Between Frequency of Physical Activity and Mortality Risk Across the Adult Age Span

Objectives: To determine if the association between frequency of leisure-time physical activity and mortality risk differs across adulthood. Method: 9,249 adults from the NHANES III (1988-1994) were categorized as middle-aged (40-64 years), old (65-79 years) or very old (≥80 years), and as inactive (0 bouts of physical activity/week), lightly active (1-2 bouts/week), moderately active (3-4 bouts/week) or very active (5+ bouts/week). Results: In all age categories, lightly, moderately, and very active adults had a lower mortality risk compared to inactive adults ( p < .001). In very old adults only, being very active was associated with a lower mortality risk compared to being lightly active (HR 0.80, 95% CI 0.64-0.98; p = .03) and moderately active (HR 0.80, 95% CI 0.65-0.98; ( p = .03). Discussion: The association between physical activity frequency and mortality risk is strongest in very old adults. All adults and particularly very old adults may benefit from participating in physical activity five or more times a week.