Physical and biological indicators of health and functioning in U.S. oldest old

This chapter examines biomarkers of aging, including indicators of physical performance and biomarkers of physiological dysregulation, among a representative national sample of U.S. adults aged 80 years and older with the aim of addressing three questions about the oldest old U.S. population: (a) How do levels of biomarkers of aging vary by age? (b) Are biomarkers of aging patterned by gender, race, ethnicity, and education? and (c) Which biomarkers of aging predict health and mortality. Data for this study come from the Health and Retirement Study (HRS). This large population-based study of U.S. adults aged 80 years and older provides confirmation of the importance of biomarkers of aging for understanding health and longevity in the oldest old. The results indicate that physical functioning declines across age groups even among the oldest old, and that the oldest adults are more likely to have levels of physical performance, inflammation, and organ function that are considered to be high risk for poor health outcomes. In addition, social disparities in physical functioning continue to be evident among the oldest segment of the U.S. population. We also provide evidence for the value of several biomarkers of aging in predicting poor health outcomes among the oldest old. In particular, indicators of high risk for walking dysfunction and dysregulation in the lungs and kidneys were found to predict hospitalization and short-term mortality.