This chapter addresses the following Geriatric Fellowship Curriculum Milestone: #8
Understand the concept, definitions, and etiologies of chronic inflammation in older adults.
Understand how chronic inflammation drives systemic changes that increase risk for adverse outcomes in older adults.
Understand present strategies and future research agendas to prevent and treat chronic inflammation and related adverse health outcomes in older adults.
Key Clinical Points
Chronic inflammation is increasingly understood as a driver of many adverse health outcomes in older adults, including functional decline, frailty, and early mortality.
Many chronic disease states including congestive heart failure, diabetes, and chronic obstructive pulmonary disease (COPD) activate chronic inflammation in older adults.
Although interventions with mild anti-inflammatory interventions are being studied, exercise interventions are to date the most effective way to reduce chronic inflammation.
Over the past two decades, it has become increasingly clear that low-grade elevations in serum levels of inflammatory mediators are strongly associated with a host of adverse health outcomes in older adults, including mobility disability, frailty, worsening chronic disease states, and early mortality. Hundreds of epidemiologic studies of older adults from populations around the world have helped to confirm and extend these findings. Although these epidemiologic studies do not prove causality, more recent basic biological studies suggest that at least some chronic inflammatory cytokines have a direct pathophysiologic impact on organs, tissues, and physiologic systems that ultimately weaken the organism, especially in the setting of aging. These pathophysiologic changes in turn contribute to the older adult’s vulnerability to adverse health outcomes.
Given the increasing recognition of the clinical relevance of chronic inflammation in disease processes and functional declines that greatly impact older adults, the ongoing study of etiologic, diagnostic, mechanistic, and potential treatments represents an important new and rapidly evolving area of investigation in geriatric medicine. Given the emerging relevance of chronic inflammation to those who care for older adults, this chapter will (1) describe evolving definitions, demographics, and measures of chronic inflammation used in the context of aging research and clinical practice, (2) review the biology that underlies chronic inflammation, (3) identify its many possible etiologies in older adults, (4) characterize the relationships between inflammatory pathway activation, multisystem decline, and the biological vulnerability observed in older adults, and (5) highlight the current and potential future interventions that may suppress chronic inflammation and reduce related adverse outcomes in older adults.
DEFINITION OF CHRONIC INFLAMMATION IN OLDER ADULTS
The activation of the innate immune system is often referred to as inflammation (Figure 4-1). It is a complex and critically important physiologic response to external threats. The activation of this system propagates a vast array of intra- and extracellular mediators that quickly act to fight acute infections and repair injuries. Activation of the immune system functions throughout the lifespan to attenuate or eliminate countless infections and injuries ...