More than 20% of our population is expected to exceed 65 years of age by 2030, with the most rapidly growing segment older than 85 years. In 2050, the population aged 65 years and older is projected to be over 83 million, almost double its estimated population of 43 million in 2012. The baby boomers are largely responsible for this increase in the older population because…
The musculoskeletal system serves three primary functions: (1) it enables an efficient means of limb movement; (2) it acts as an endoskeleton, providing overall mechanical support and protection to soft tissues; and (3) it serves as a mineral reservoir for calcium homeostasis. In older adults, the first two of these functions frequently become compromised; musculoskeletal problems are a major cause of pain and physical disability in…
Aging is a continuous process that constitutes a cycle studded with events that affect all systems in the body, including the connective tissues. The interrelationship between the aging process and connective tissues is complex, involving a variety of factors and interactions acting in a reciprocal fashion. One could inquire into the effects of aging on connective tissues and, conversely, one may ask how the components of…
Neurologic disorders are a common cause of morbidity, mortality, institutionalization, and increased health care costs in the older adult population. Not only does advancing age increase the frequency and severity of neurologic disease, but it may also play an important role in modifying disease presentation. Although physical difficulties can occur independently of cognitive decline, physical difficulties coexist with cognitive impairment in many seniors. Data from the…
Respiratory Function Tests The commonly used respiratory function tests are presented in this chapter. In addition, patterns of lung function abnormality seen in some of the common types of condition are also presented. Breathing parameters include the following: Forced expiratory volume (L) in 1 second, FEV 1 . This is the volume of air expired during the first second of a forced expiratory maneuver from vital…
Advanced age is a major risk factor for the development of cardiovascular disease. Why age increases the risk of cardiovascular disease is debatable. The increased risk might arise simply because there is more time to be exposed to risk factors such as hypertension, smoking, and dyslipidemia. In other words, the aging process itself has little impact on the cardiovascular system. However, an emerging view is that…
Introduction Overview of Frailty Geriatricians have an affinity for frail older people, or should. The complex care of older adults who are frail is the very stuff of geriatric medicine. This chapter argues that the formal assessment of complexity can be used to understand the scientific basis of the analyses of frailty, with insights for the practice of geriatric medicine. It takes the view that aging…
Demographic trends show that independently of geographic regions and socioeconomic background, the absolute and relative number of older persons is increasing worldwide. It has been estimated that the prevalence of persons aged 65 years and older worldwide will increase from 7.7% in 2010 to 15.6% in 2050. This trend is evident even among the subpopulation of those aged 80 years and older, which is predicted to…
Neuroendocrine aging is a multifactorial process that typically spans years and is characterized by sequential phase transitions. These transitions are progressive in nature and are typified by stages of system-level changes in function, followed by compensatory adaptations. Furthermore, phase transitions are typically nonlinear processes that are more consistent with a step function from one state to another. Transition states are separated by intervening periods of apparent…
Introduction “Stress” is often identified as a factor in accelerated aging, an important factor in disorders such as cardiovascular disease and depression, and a contributor to other disorders. Being “stressed out” is a commonly used expression that generally refers to experiences that cause feelings of anxiety, anger, and frustration because they push a person beyond his or her ability to successfully cope. Besides time pressures and…
Environmental stressors and several genetic pathways play complex and crucial roles in the neurobiology and control of aging. This chapter will summarize current knowledge on these two specific research areas divided into two sections, one on free radical stressors and the other on genetic control of metabolic pathways. Nitrosative and Oxidative Stress in the Neurobiology of Aging Tomohiro Nakamura Stuart A. Lipton Aging represents a major risk factor…
Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare, uniformly fatal, segmental premature aging disease in which children exhibit phenotypes that may give us insights into the aging process at the cellular and organism levels. This chapter will compare HGPS to normal aging with respect to its genetics, biology, clinical phenotype, clinical care, and treatment. By looking carefully at one of the rarest diseases on earth, we…
Introduction Aging changes are universal within a species and are intrinsic and progressive. They are universal; each true aging change should develop in all individuals in a species if they live long enough. Aging is intrinsic because these changes occur despite environmental cues, although the environment can alter their timing. The term progressive refers to the time dependency of aging processes. After adulthood, aging is associated…
Introduction Our society is experiencing unprecedented demographic changes where improvements in health care and living conditions together with decreased fertility rates have contributed to the aging of the population and a severe demographic redistribution. Over the last 50 years, the ratio of people aged 60 years and over to children younger than 15 increased by about half, from 24 per hundred in 1950 to 33 per…
Introduction From the biologic perspective, aging is a rather complex term to define. Aging is not a disease but, because aging is the main risk factor for so many chronic diseases and conditions, it is difficult to separate the two operationally. Richard Miller of the University of Michigan defines aging as the “process that progressively converts physiologically and cognitively fit healthy adults into less fit individuals…
Introduction The difficulty of undertaking research involving older people tends to be exaggerated. It is wrongly assumed that too many will have significant comorbidity leading to a poor signal-to-noise ratio, an unacceptably high risk of adverse events, inability to complete necessary assessments, poor compliance, and high dropout rate. This can translate into arbitrary, unscientific, and unnecessary upper age limits. However, many of the changes commonly attributed…
The question “Why does aging occur?” calls for answers at the level of proximate physiologic mechanisms and at the level of ultimate evolutionary origins. This chapter provides an understanding of why aging has evolved and examines what evolution theory can tell us about the types of mechanisms we might regard as prime candidates to explain senescence. Evolution theory is well recognized as a powerful tool with…
Demography of Centenarians According to the U.S. Social Security Administration, in 2010, approximately 51,000 people aged 100 years and older collected Social Security benefits. The U.S. census reported a similar number of 53,364 and an overall prevalence of 1.73 centenarians/10,000 people, with 80% of centenarians being women. In the 1980s and 1990s, centenarians were deemed the fastest growing age group in the population (65.8% from 1980…
Biogerontology, the field of biologic aging research, is the final biomedical research frontier. The sequencing of the human genome and advancements in molecular technology have provided enormous potential for regenerative medicine. The list of readily replaceable body parts (e.g., eye lenses) and organs (e.g., hip joints, arterial transplants) will continue to grow. Even 30 years ago, little could be done to treat cataracts, but now lens…
Introduction According to Wikipedia, epidemiology is defined as “the science that studies the patterns, causes, and effects of health and disease conditions in defined populations.” Epidemiology was first concerned with epidemics of infectious diseases when these were the main cause of death. However, with what demographers termed the epidemiologic transition , when the main cause of death in most populations worldwide shifted from infectious to noninfectious…