| Research Abstract |
During the past several decades, the concept "quality of life" in human has emerged as a very important attribute of clinical investigation and patient care. Nowadays, quality of life (QOL) is used as a multi-dimensional facet for healthy, successful aging. In Japan, as well as in some industrialized Western countries, despite the increase in morbidity, the decline in mortality among middle-aged and older adults has contributed substantially to gains in overall life expectancy. For the moment at least, we may be enjoying an extraordinary revolution in longevity. An increase of over 25 years of life expectancy from birth in the developed world is nearly equal to what had been attained during the preceding 5,000 years of human history. Thus, we are experiencing a continuing historic revolution of longevity. U.N.population figures note a gain in life expectancy in recent years in the developed world from 71 to 74.6 compared to 54.5 to 62.4 in the developing world. The developing world has
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therefore gained greater numbers of older people, but has not gained longevity equal to the industrialized nations. The industrialized nations will have to respond to environmental threats (ecological destruction) as well.
The population of individuals aged 65 yr and older currently numbers approximately 14 million, representing 12% of the total Japanese population, and is expected to approach approximately 30 million, or 25% of the population, by the year 2025. Moreover, U.N.projects that by the year 2025 the population of old persons aged 65 yr and over will exceed 8 million in the world, comprising approximately 10% of the overall population as opposed to 6.2% today. In 1850 there were one billion people on teh globe. A century later, 1950,2 billion, a doubling! Forty years later 5.3 billion and by the 2025 a projected 8.5 billion! Population expansion is a major threat to longevity. Some countries such as Japan and those of Europe, which worry about decling population, on the contary, should also take another (different) heart. These countries have reached the so-called "demographic transition, " the point where the birthrate falls probably due to increasing income and education. Japan's population in 2025 will be approximately the same as it is today. With these in mind, we have to promote the democratization of longevity with universal access to health care and its technologies and meet other goals.
It is generally agreed that long life without good health and adequate physical functioning is undesirable, yet a great number of people actually live their terminal years in a state of increasing morbidity, and sometimes in almost complete physical and/or mental dependency. Given the projections for a progressively increasing number of persons experiencing morbidity, the emphasis on gerontological research has shifted from lengthening life to increasing years of qualitative health by compressing the time spent in morbidity. The compression of morbidity contributes significantly to raising the quality of life in most persons, particularly in the functionally impaired and frail elderly. Thus, one of the major goals of our research area, interdisciplinary gerontology, is to help compress the period of time during which older adult individuals live in a state of morbidity, and to help extend the lifespan during which they can live with high vitality and good health status. This should be defined as having "optimal quality of life". The time has come for scientists to attempt to develop environments which can help stimulate "successful aging" or "optimal quality of life"
Aging is a societal issue that never previously occurred in the history of humankind, with resultant problems that are very difficult to overcome. It is inevitable, progressive, irreversible and universal. However, the possibility exists that part of aging is reversible, because it is usually accompanied by multiple, chronic, incurable decrements of health and function, some of which can be modified by collections of a number of individual health-related behaviors coupled with the aid of sound environmental conditions. It may well be that aging is a highly individualized process, resulting in large inter-and intra-individual differences in health and function. Recognition of this variability may prove valuable in devising primary and secondary aging process interventions.
The leading causes of death in Japan are cancer, heart disease, and cerebrovascular disease (or stroke). All of these major causes of death, particularly the first two, are considered to be partial by-products of inappropriate lifestyle choices and habits ; that is, lifestyle-related causes of death. Unfortunately however, some people do not understand the relatively close link between health and discretionary lifestyle. There is nothing an individual can do about age, gender, and heredity, but The earlier in life that these changes are made, the better. It is never too late to initiate healthy habits to slow progression of chronic dieseases and associated risk factors. Certain fundamental lifestyle choices ultimately dicate health and longevity for each individual.
With the above in mind, QOL was defined as follows in the present study. The QOL in the older adult population can be affected by a number of factors. Included among those factors are health status, physical function, energy and vitality, sexual function, cognition, emotional stability, feelings of well-being, life satisfaction, social integration (environment), recreational activity, nutritional status, economic factors, and many others. While some of these factors are modifiable by lifestyle choices, it is increasingly apparent that many of the factors that influence optimal QOL in older adults are highly dependent upon one another, so that if we are to understand how these factors influence optimal QOL,it will be necessary for scientists to develop complex multivariate measures before we can adequately assess functional status in older adult populations. Thus, it is especially important that scientists develop an overall instrument of optimal QOL,with the aid of a wide range of interested parties, including policy makers and planners, health care providers, social workers, and perhaps most importantly, with older adults themselves. Since the physical dimension of life, which includes health status, physical vitality, nutritional status, and life satisfaction, contributes in a very significant way to optimal QOL for the elderly, it is anticipated that substantial reductions in morbidity would be accomplished by the widespread implementation of physical activity programs in the older adult population. Chronic and systematic exercise throughout life may be assumed to provide many health benefits, other than just staying alive. Higher levels of cardiorespiratory capacity, muscular strength, and physical flexibility (joint mobility) enable any individual to be more generally active and expand the range of physical and social activities in which he or she can participate. We assume that physical acitivity has significant physiological, psychological, and social benefits for almost all older adults.
Of special interest in the present research project is the substantial contribution that the physical dimension of life, consisting of health status, physical vitality, mental vitality, nutritional status, and life satisfaction can make to the ovarall QOL.Health status and/or physical vitality can be evaluated by the use of vital age which is a modified index of biological age. Nutritional status would be scored between 20 and 80 with a mean of 50 (SD 14). A review of both the English-language and the Japanese-language research strongly suggests that "overall QOL" is heavily dependent upon many of the factors we plan to include in our overall index of "QOL". Unfortunately, to date, there is little concensus with respect to how precisely to measure "QOL" in older adult populations. Indeed there is a real need for more research in this area. Accordingly, the goal of the present research proposal is to develop more definitive procedures for the measurement of overall QOL of Japanese middle-aged and elderly people.
The following are major findings obtained in each of the sub-studies.
(1) Reliability and Objectivity of the Test Items to Assess Functional Fitness Required for Performing Activities of Daily Living in Japanese Elderly Women.
First of all, the present study examined reliability and objectivity of 17 test items representing functional fitness in Japanese elderly women. In reliability study, 207 subjects, between 60 and 91 years of age, performed each test twice a day. Though the score of the second trials in 10 test items tended to be better (P<0.05) than that of the first trials, three types of correlation coefficients that were used as an index of reliability (Pearson's product moment, Spearman's rank order, and intraclass) were all 0.67 or higher (P<0.05) with the exception of the bar reaction, standing up from a supine position, one-leg balance with eyes open, and one-leg balance with eyes closed. In order to obtain a more reliable score, it is suggested that a more amount of time for warm-up and test practice is necessary before the actual test is begun. The data collected in two days, each one to two weeks apart, showed a high objectivity (r=0.94, p<0.05) with no significant differences between two means. These results may lead to an important step towards establishing an appropriate test battery to assess functional fitness in Japanese elderly women.
(2) A Physical Performance Battery Assessing Low/High Extremity Function in Japanese Elderly Women
The aim of the second study was to establish a physical performance test battery in order to assess the wide variation of function in the Japanese elderly. The criteria for sampling low/high extremity function were the amount of physical activities in their leisure time and the distance (or locality) which they could move on foot. Evaluations of 17 items related to the activities of daily living (ADL) were performed for 178 women (aged 60-91). The coefficients of variation (CV) in 11 of 12 items including the age were larger than the CVs observed in other studies for Japanese older women. After principal component (PC) analysis, the 17*17 correlation matrix (n=140) for the 17 performance items showed 5 factors which accounted for 63.5% of the total variance. The first PC accounted for 31.4% of the variance and the eigen vectors of 14 items were larger than 0.4. Considering these results, test-retest reliability, kurtosis, and skewness of each item, the following 4 items were selected for the battery : repetition of the bicipital flexion/extension, moving beans with chopsticks, walking around cones and sitting on a chair and functional reach. Two factors from these 4 informative variables were extracted by the second PC analysis. The first PC score obtained in the second analysis was computed for subjects in the exercise group (n=19) and sedentary group (n=19). Biserial correlation coefficient as an index of cross-validity was 0.53 (P<0.05) between each group. These results suggest the possibility that any levels of physical function can be comprehensible and useful for the performance of ADL.
(3) The Influence of Functional Fitness on Life Satisfaction of Elderly Japanese
The objective of the third study was to develop a life satisfaction scale and to consider the relationship of functional fitness status with life satisfaction in elderly Japanese people from the perspective of Quality of Life (QOL). A total of 352 elderly men and women (74.1<plus-minus>5.7 years) participated in a questionnaire study, and 178 of them were tested for functional fitness. The life satisfaction scale questionnaire was comprised of 72 questions hypothetically covering seven structural domains regarding feelings of life satisfaction in elderly people. The functional fitness test consisted of 9 test items representing the fitness areas : muscle strength, agility, coordination, balance, and flexibility. From the application of factor analysis for the above questionnaire, a useful life satisfaction scale consisting of 21 questions covering 8 domains was constructed. The analysis of data also revealed that the feeling of life satisfaction among elderly people has a significant relationship with their functional fitness. From these results we can see that it is importnat to maintain the level of functional fitness so as to enable a high, optimal QOL in elderly peopl
(4) Development of a Twelve-minute Treadmill Walk Test at a Self-selected Pace for the Evaluation of Cardiorespiratory Fitness in Adult Men
Fourthly, it was aimed to develop a simple test that could accurately estimate cardiorespiratory fitness using a submaximal treadmill walking protocol for older, sedentary individual and patients with chronic disease. Subjects for this study were 42 men (44.9<plus-minus>15.7 years), which included 17 patients with coronary heart disease (57.0<plus-minus>9.6 years). VO2peak and VO2AT were measured using a treadmill protocol (VO2peak ; 38.4<plus-minus>11.6 ml/kg/min, VO2AT ; 22.9<plus-minus>7.4 ml/kg/min). This simple test assessed the total distance covered in 12 minutes on the treadmill at an intensity corresponding to either ; (1) 11 on the Borg scale of ratings of perceived exertion (RPE11), (2) 13 on the Borg scale of ratings of perceived exertion (RPE13), or (3) "Optimal" by subjective judgment. The correlation coefficients between VO2peak or VO2AT and total distance at the three intensities (RPE11 ; 950<plus-minus>100 m, RPE13 ; 1080<plus-minus>140 m Optimal ; 1050<plus-minus>110 m) were statistically significant, ranging from 0.72 to 0.85. The test-retest reliability coefficient on 12 subjects was 0.98. The oxygen uptake (VO2) was measured during the three walk tests on 15 subjects. There were no significant differences in submaximal VO2 values from min 4 to min 12 ( RPE11 ; 19.8<plus-minus>4.7 ml/kg/min, RPE13 ; 24.1<plus-minus>4.9 ml/kg/min Optimal ; 23.1<plus-minus>4.8 ml/kg/min) in any of the three tests. Similarly, the three submaximal VO2 values did not differ from the VO2AT value (21.2<plus-minus>8.3 ml/kg/min) from the original maximal test. These results suggest that the 12-minute submaximal treadmill walk test (STWT) is a valid method for the assessment of VO2peak and VO2AT.Therefore, the STWT could be a useful performance test for evaluating cadiorespiratoy fitness in older, sedentary individuals and patients
(5) Validation of a Simple Method for the Assessment of Health-related Physical Fitness in Japanese Men
The next step as the fifth study was to develop a useful equation for estimating the health-related physical fitness (HRPF) age of Japanese men. This measure consists of 4 independent variables (maximal oxygen uptake, standing trunk flexibility, body fat, and muscular strength). However, the direct measurement of maximal oxygen uptake (VO2max), which is one of independent variables, is not always practical. In the present study, we attempted to assess the HRPF age more esily by substituting VO2max with a simpler predictor. We selected a questionnaire method and a 12-min submaximal treadmill walk test (STWT) as a substitute for VO2max test. Three HRPF ages were computed on 18 Japanese men (54.3<plus-minus>11.4 years) using actual VO2max (actual HRPF age), questionnaire estimated VO2max (predicted HRPFq age), and STWT VO2max (predicted HRPFs age). The HRPF ages averaged 61.9<plus-minus>14.0,62.2<plus-minus>12.3 and 62.4<plus-minus>13.5 years, respectively. Analyzes of the data indicated that the HRPFq age and the HRPFs age were highly correlated with the acutual HRPF age (r=0.97 and r=0.95). When one-way ANOYA was used to compare mean differences among the three HRPF age scores, no significant differences were found. These results suggest that substituting VO2max with a questionnaire or STWT is acceptable in assessing the HRPF age of Japan
(6) Characteristics of Activity Fitness of Daily Living in Elderly Korean Women
The purpose of this study was to investigate activity fitness of daily living of elderly women in Korea. The subjects were 253 elderly women between 65 and 84 years of age. Twenty items related to the activity fitness of daily living were measured. The person's correlation coefficients between the performance test items and age were significant (P<0.05) and the score of all items remarkably decreased with aging. In order to extract activity fitness of daily living, the principal component analysis was applied to the 20*20 correlation matrix. The first principal component was interpreted as fundamental activity fitness (FAF) of daily living. The results of the comparison clearly indicated that the 75-79 and 80-84 age group were inferior to FAF of daily living. Furthermore, in order to analyze the factorial structure of these elderly women, extracted factors were rotated with normal varimax criterion. The activity fitness (AF) of daily living categorized to 7 factors : muscular strength and movement of the whole body, flexibility, balance, coordination of upper limbs, agility of upper and lower limbs, endurance, and raction. The results of the comparison with the AF factors with aging, showed that decline was significant to musclular strength and movement of the whole body. The prediction equations of FAF were developed using multiple regression analyzes. It indicated that the selected 8 items from 7 factors were significant predictors of the dependent variable FAF.It equally clarified the fact that out of our 8 items three could be excluded and the result would still yield comparable precision in predicting FAF.On the basis of all our analyzes and considering the practicability of the measurement, we recommend the equation FAFS=1.504X1-0.838X2-0.489X3-0.363X4-0.686X5+68.71, with an R=0.850 ; where FAFS=fundamental activity fitness score, X1=arm curl, X2=walking around two chairs in a figure 8, X3=one foot tapping in a sitting position, X4=sit and reach, X5=carring beans using chopsticks, which can predict FAF with high precision in elderly Korean women.
(7) Comparison of Physical Activity of Daily Living between Japanese and Korean Elderly Women
Japan and Korea and the most nearest countries geographically and similar in culture, but a different socioeconomically. There are few comparative studies between both countries. The purpose of this study was to compare physical activity of daily living (PADL) and its components in a wide variety of age between Japanese and Korean elderly women. The subjects were 434 (181 Japanese and 253 Korean) elderly women, aged 65 to 91 years. Seventeen items related to PADL were measured. The Pearson's correlation coefficients between the performance test items and age were significant and the score of all items remarkably decreased with aging. In order to extract the overall PADL,the principal component analysis was applied to the 17*17 correlation matrix. The first principal component was interpreted as fundamental PADL.The results of the comparison clearly indicated that the Korean elderly women were inferior to Japanese elderly women in the fundamental PADL level. Furthermore, in order to analyze the factorial strucuture for these elderly women, extracted factors were rotated with normal varimax criterion. The PADL was found to consist of agility of the hand and foot in a seated position, strength and movement of the body, flexibility of the upper and lower limb, flexibility of the trunk, balance, reaction of the hand and leg endurance. The results of the comparison with the PADL components between Japanese and Korean elderly women showed that the Japanese elderly women were significantly superior in agility of the hand and foot in a seated position, strength and movement of the body, flexibility of the upper and lower limb, balance, and leg endurance, but were not different in flexibility of the trunk and balance. From these results, it is concluded that the effects of age was significant for all items in elderly women of both country, and that the higher PADL level contributed to a lifestyle of vigorous physical activity in Japanese elderly women. Less
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