Aging and Multimorbidity: New Tasks, Priorities, and Frontiers for Integrated Gerontological and Clinical Research

Abstract

Aging is characterized by rising susceptibility to development of multiple chronic diseases and, therefore, represents the major risk factor for multimorbidity. From a gerontological perspective, the progressive accumulation of multiple diseases, which significantly accelerates at older ages, is a milestone for progressive loss of resilience and age-related multisystem homeostatic dysregulation. Because it is most likely that the same mechanisms that drive aging also drive multiple age-related chronic diseases, addressing those mechanisms may reduce the development of multimorbidity. According to this vision, studying multimorbidity may help to understand the biology of aging and, at the same time, understanding the underpinnings of aging may help to develop strategies to prevent or delay the burden of multimorbidity. As a consequence, we believe that it is time to build connections and dialogue between the clinical experience of general practitioners and geriatricians and the scientists who study aging, so as to stimulate innovative research projects to improve the management and the treatment of older patients with multiple morbidities.

Keywords: Multimorbidity; aging; chronic disease; multiple morbidities.

Fig. 1

The age-related multisystem loss of reserve and function, rooted in the biological determinants of the aging process, is associated with increased susceptibility for chronic diseases, which becomes clinically evident as multimorbidity when a certain threshold of impairment has been a reached.

Fig. 2

The accumulation of chronic diseases with increasing age, which is strongly associated with changes in all aging phenotypes and high risk for physical and cognitive decline, disability and mortality, can be conceptualized as a fulcrum of the aging process and a proxy measure of the speed of aging. Relationships and associations already established and recognized are represented by solid arrows, whereas those that have been hypothesized but not fully explored or understood are represented by dotted arrows.