Chapter 18 - The endocrinology of aging

Abstract

As with all other organ systems, the endocrine axes are subject to physiological and pathological changes with aging. The purpose of this chapter is to assist the reader in the diagnosis of the latter in the context of the former. That is, as physicians and laboratorians, we must be able to distinguish the normal effects of aging on the patient’s clinical presentation and biochemistry from those of disease states. Unfortunately, there are many contexts where normal aging and pathophysiology have phenotypic overlap to the point where the distinction between the two may become more philosophical than biomedical. To that end, this chapter will review the endocrine axes delineating some of the known physiological changes and their effect on reference intervals and diagnosis of specific disease entities. Particular attention will be paid to issues that commonly arise in clinical practice. Unfortunately some of the questions posed in clinical practice are generated from an industry of “wellness” and “antiaging” medicine that has found an entrepreneurial niche in some Western countries. Between the effects of trends in medical entrepreneurship and the rise in the average life span, these diagnostic challenges are becoming increasingly prevalent and the clinician must be prepared with a diagnostic strategy and approach in response to pressure to treat what may be entirely normal—where the treatment itself may have no proven scientific benefit and may pose risk of harm.