Current guidelines recommend regular exercise to reduce the risk of death and cardiovascular morbidity from all causes. However, evidence supporting the benefits of exercise in older adults with cardiovascular disease (CVD) is scarce because studies on physical activity and mortality have been conducted primarily in healthy, middle-aged people.
The objective of this study was to analyze the association between the change in exercise habits after a new diagnosis of CVD and the risk of death from any cause, cardiovascular or non-cardiovascular.
| Methods |
We analyzed the relationship between exercise habit change and deaths from all causes, cardiovascular and non-cardiovascular, in adults ≥ 60 years of age between 2003 and 2012 who underwent two consecutive health examinations within 2 years before and after of the diagnosis of cardiovascular disease (CVD).
Leisure-time exercise levels at each health examination were assessed using self-report questionnaires developed from the International Physical Activity Questionnaire.
They were classified into four groups according to changes in exercise habits: persistent non-exercisers, exercise abandoners, new athletes, and exercise maintainers.
| Results |
Of 6076 participants, the median age was 72 years and men accounted for 50.6%. There were 2871 persistent non-practitioners (47.3%), 754 exercise abandoners (12.4%), 1363 new practitioners (22.4%) and 1088 exercise maintainers (17.9%).
Compared with persistent non-athletes, new exercisers and maintainers were associated with a reduced risk of death from all causes.
The non-cardiovascular death rate was significantly lower in new exercisers and maintainers of exercise than in persistent non-athletes. In addition, trends towards reduced cardiovascular death were observed in new athletes and exercise maintainers.
| Discussion |
The main findings of this nationwide population-based cohort work that classified patients according to changes in exercise habits after a first CVD incident are summarized in three main points:
• First, maintenance of exercise was associated with a reduced risk of all-cause cardiovascular or noncardiovascular death.
• Second, a trend of progressively lower mortality rates was observed with increasing exercise from those who persistently did not exercise to those who maintained activity.
• Finally, among patients younger than 75 years, those who were physically inactive tended to have a higher risk of cardiovascular death and those with a regular exercise habit tended to derive greater benefits from exercise than their counterparts among patients older than 75 years. .
> Single assessment of exercise habit versus assessment of change in exercise habit
Previous studies have already described not only that a single assessment of exercise habits has limited predictive power in estimating long-term cardiovascular risk but also that the change in exercise habits between the time of inclusion and the second assessment remains an independent predictor of death. Furthermore, the impact of selection bias on the association between exercise habits and death should be considered in large prospective cohort studies, which were primarily based on contemporary exercise guidelines.
For these reasons, participants were classified into four groups based on their change in exercise habits. This may have allowed us to discriminate the benefits of exercise alone from the influence of other confounding risk factors that have been improved by cumulative gains. Thus, the present study confirms the benefits of exercise in preventing death, especially when the results among those who maintain the activity are considered.
> Change in exercise habit after CVD diagnosis and death
A recent cohort study found that a higher level of exercise not only tended to reduce the risk of death from all causes among patients with CVD, but also resulted in a greater survival benefit than in people without CVD. The present results were consistent with these findings and were robust even after adjusting for covariates and subsequent analysis in subgroups divided according to age, sex, degree of comorbidities and type of CVD.
> Change in exercise habits and death in older adults
The WHO guideline describes the impact of regular intensity exercise. Physical inactivity is a well-known risk factor for all-cause and moderate all-cause cardiovascular deaths in older adults. However, it simply extrapolates the conclusion of studies that showed benefits in middle-aged adults because no upper age limit criterion was established.
Few studies to date have investigated a specific group of older people, and some studies have failed to prove that exercise improves prognosis. The current study showed that starting or maintaining regular exercise was associated with a lower risk of death from all causes, cardiovascular or non-cardiovascular.
Although the results among new athletes were not statistically significant for cardiovascular death, they were consistent with the trend observed in the main analysis regardless of various sensitivity and subgroup analyses.
In this study, although patients ≥75 years of age had reduced benefits with respect to death prevention compared to those younger than 75 years, the benefits were statistically significant. Therefore, the results suggest that the adoption and maintenance of regular exercise should not be ignored in older patients, even considering the reduced benefits obtained from exercise.
> Limitations of the study
Recall bias is an important limitation because the information on habits was based on self-report questionnaires that asked about lifestyle behaviors during the previous week.
The level of physical activity before and after CVD diagnosis was assessed using a questionnaire with a 1-week recall, assessing physical activity over a 7-day period rather than the entire period before and after the cardiovascular event. Therefore, the level of exercise could not be precisely defined.
Several types of physical activities, including low-intensity exercise, housework, occupational activities, and transportation-related physical activities, were not included or analyzed.
Finally, since only the Korean population was able to participate in the study, ethnic differences could limit the external generalizability of the results.
| Conclusions |
Initiating or maintaining at least 5 days of moderate-intensity activity or 3 days of vigorous-intensity activity per week is associated with a reduced risk of all-cause, cardiovascular, and noncardiovascular deaths in older adults with newly diagnosed CVD.
The results support public health recommendations for older adults with CVD to engage in physical activity. Exercise is important and should be recommended.
