Editorial
Impact of Frailty on Cardiovascular Disease in Older Adults
2023 Volume 30 Issue 9 Pages 1104-1105
Details
2023 Volume 30 Issue 9 Pages 1104-1105
See article vol. 30: 1115-1122
Frailty indicates a decline in biological reserve and resistance to stressors, resulting in vulnerability to adverse outcomes1) in the physical, psychological, and social domains. Frailty, especially physical frailty, is associated with an increased risk of adverse health outcomes, which can significantly impact life expectancy in the elderly population. Recently, frailty has been reported to be associated with an increased risk of cardiovascular disease (CVD) incidence or death in older adults in several countries, including Japan2-4). In addition, a previous report showed that weak handgrip strength, a component of phenotypic frailty, was associated with all-cause and CVD death in Japanese older adults5). Furthermore, Tobe and colleagues reported that handgrip strength was inversely associated with the composite endpoint of all-cause death, the incidence of myocardial infarction, and readmission due to heart failure in Japanese older adults who underwent percutaneous coronary intervention6). These findings indicate the importance of frailty management for CVD prevention in Japanese older adults.
Several mechanisms have been proposed for the relationship between frailty and CVD2, 7). Frailty is strongly associated with multimorbidity, including subclinical atherosclerotic diseases, hypertension, and diabetes, and these comorbidities may contribute to the increased risk of CVD in frail populations. A previous report showed that frailty was associated with poor lifestyle habits that affect cardiovascular health, and lifestyle modification may reduce CVD risk in frail and pre-frail populations7). In addition, the pathophysiological mechanisms underlying frailty and CVD include chronic inflammation, increased insulin resistance, and endocrine dysregulations, which may confound the association between frailty and CVD. Furthermore, changes in the morphology and function of the vascular system associated with aging may lead to a decline in brain and muscle function, resulting in frailty progression and CVD development. However, the mechanism through which frailty contributes to CVD development remains unclear, and further research is needed to elucidate this mechanism.
Several factors should be considered in the interpretation of the results of observational studies examining the association between frailty and CVD incidence or death. First, definitions of frailty and the scales used to measure frailty vary among studies. A commonly used criterion is the criterion for phenotypic frailty proposed by Fried and colleagues, which was validated based on the Cardiovascular Health Study1). This criterion consists of five items: weakness assessed by grip strength, slowness from usual gait speed, exhaustion derived from a self-reported fatigue questionnaire, low activity based on estimated energy expenditure calculated from a physical activity questionnaire, and unintentional weight loss, with phenotypic frailty being confirmed when three of the five items are met. This criterion considers frailty as a biological syndrome due to the decrease in the physiological reserve and represents the physical aspect of frailty. Another commonly used criterion for frailty is the frailty index developed by Rockwood and colleagues using data from the Canadian Study of Health and Aging, which studied the cumulative effect of medical, functional, and psychosocial age-related deficits8). The frailty index considers frailty as a spectrum of aging and is suitable for frailty management. Several scales have been developed to assess frailty, including the revised Japanese version of the Cardiovascular Health Study (J-CHS) criteria and the Kihon Checklist. Results should be interpreted based on an accurate understanding of the concepts used in such scales. Second, definitions of CVD differ among studies. For example, when CVD is defined using ICD codes in the literature, whether heart failure or transient ischemic attack is included in CVD remains ambiguous. Third, the definition of CVD incidence comprises the incidence of only symptomatic CVD because the measurement of the incidence of asymptomatic CVD, such as asymptomatic lacuna infarction, has been a major challenge in most epidemiological studies. Finally, non-CVD death as competing risk is not considered in the association between frailty and CVD incidence or death in most observational studies. A previous study revealed that frailty led to an increased risk of non-CVD death9); thus, the relative risk of frailty for CVD death may be overestimated by ignoring the competing risk for non-CVD death.
The prevention of frailty is important for extending healthy life expectancy in Japan, where the elderly population is increasing. In particular, physical frailty is a manageable condition that can be targeted for intervention, and the assessment of physical frailty for older adults is necessary in medical and community settings. Resistance and aerobic exercises, caloric and protein supplementation, vitamin D supplementation, and polypharmacy reduction are recommended to prevent the progression of physical frailty and extend healthy life expectancy among older adults10). More evidence needs to be accumulated on whether prevention of physical frailty in older adults can directly prevent CVD. Nevertheless, based on the findings of previous reports, assessment of physical frailty may be necessary for improving the prognosis of older adults with CVD.
None.
