Healthy Aging Longitudinal Study in Taiwan

In the proposed research, investigators plan to conduct a longitudinal study on a cohort of 5,000+ men and women ages 55 years or older to address issues related to healthy aging. The study population consists community-based middle to old aged men and women in the catchment area of 7 hospitals (2 in the north, 2 in the middle, 2 in the south and 1 in the east, about half urban half rural). In this proposed study, investigators will recruit the subjects in the catchment area of the above 7 hospitals and expand data collection to include more interviewer-administered data, physical examinations and blood and urine specimens.

In addition, the cohort will be followed annually for mortality and morbidity and will be re-examined every five years.

For this newly proposed study, in order to systematically address issues related to healthy aging, specific aims are grouped into five inter-related areas of emphasis (five component projects). The five component projects are:

A. Factors that may influence physical functioning and its changes in older persons.

B. The benefit of healthy lifestyles on cardiovascular disease risk profile, quality of life and physical functioning in older persons.

C. Individual and macro-level risk factors of cardiovascular disease in older persons.

D. Neuropsychiatric disorders in the elderly: risk factors and impact on health.

E. Genetic and environmental factors for frailty/successful aging and related chronic diseases in the elderly.

The proposed starting date is on March, 2008. The first nine months will be devoted to the development of protocol, manual of operation, pilot testing, central training, and dress rehearsal. The baseline examination will begin in November, 2008 and will last for 4 years. The examination will consist of three parts, a home visit, a clinic examination and the Heart Rate Variability. The home visit will include interviewer-administered questionnaires (informed consent, contact/follow-up information, sociodemographic data, health condition/medical history, family disease history, physical functioning, geriatric conditions, mental health, cognitive function, social and health environments, lifestyles and quality of life, etc.) and physical assessment (peak flow test, grip strength, and physical performance measures). It is estimated that the home visit will take up to 2 hours. The clinic examination will include urine collection, blood pressure, phlebotomy, Primary Care Evaluation of Mental Disorders (high risk people only), anthropometric measures (body height, weight, and circumference measures of waist and hip), body composition, visual test, clock drawing test, the Digit-Symbol Substitution Test, EKG, Heart Rate Variability (HRV), Ankle Brachial Index(ABI), Dual Energy X-ray Absorptiometry (DXA), physical examination, three mobility tests (single leg stance, timed up and go, and six-minute walk test), and a brief questionnaire. The clinic examination is estimated to take approximate 2.5 to 3 hours. Quality of the data collection will be continuously monitored. Two rounds of Heart Rate Variability (HRV) measurements will be conducted. During each round, the HRV will be measured twice with a total duration of about 40 minutes. Those who have installed pacemakers will be excluded from investigators HRV examination. The first round of HRV test will be conducted during the clinic examination, and the second round will be performed about one week later. It is estimated that about 60 participants will need to be enrolled in the HRV test, and each participant needs to complete four times of HRV measurement. This repeated measurement of HRV will allow us to test whether the reliability of investigators HRV measurement is acceptable with an intraclass correlation coefficient (ICC) of at least 0.6 (α=0.05, 1-β=0.8). The HRV test will be stopped when at least 60 participants are enrolled at Taipei site. The responsible investigators and the co-investigators are experienced in the corresponding areas of research. They have been collaborating successfully on various projects for many years. During the study, the investigators will meet via conference call or face-to-face meeting twice a month to discuss issues related to the examination, quality of data, scientific direction, data analyses and manuscript preparation. The proposed study will provide a unique opportunity to enhance investigators understanding of the cardiovascular disease risk factor profile, physical and mental performance and functioning, frailty, quality of life, and morbidity and mortality in a representative cohort of older people in Taiwan. It will provide an opportunity to assess the effects of healthy lifestyles on the prevention of chronic illnesses, disability, and quality of life in older ages. This study of the effects of healthy lifestyles in middle and older ages on overall health among older persons, as investigators propose, has particular societal relevance given the marked growth in numbers of older persons in the Taiwanese population, and their extensive chronic disease-related morbidity, disability, loss of independence, large health care costs, and mortality. Positive results from this study will inform policy regarding the allocation of resources for promoting healthy lifestyles so that the aging population can compress the onset of morbidity and disability, maintaining high quality of life and reducing health care costs.