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This chapter addresses the following Geriatric Fellowship Curriculum Milestones: #9, #66
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Learning Objectives
Identify and manage common endocrine disorders that occur in older adults.
Describe altered presentations of endocrine disease that reflect impaired homeostatic regulation of endocrine systems.
Describe the pathophysiology of common endocrine disorders in older adults.
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Key Clinical Points
Endocrine disorders often present nonspecifically or atypically in older adults. As a result, it is often necessary to perform laboratory screening to identify these disorders, but there is no firm consensus on appropriate screening practices for endocrine disorders in asymptomatic older adults.
Although there is some evidence that melatonin may be safe and effective for short-term treatment of insomnia in older adults, the long-term risks and benefits of melatonin supplementation for any indication remain to be determined.
Evaluation of pituitary tumors should include hormone measurement to exclude hypersecretion and hypopituitarism, along with visual field examination for tumors adjacent to the optic chiasm or optic nerves. Incidentally discovered pituitary microadenomas (< 10 mm in size) are less likely to grow than larger adenomas, so observation may be appropriate.
The functional significance of an empty sella discovered incidentally on imaging in apparently healthy older people is unclear. Conservative management is indicated, with visual field testing and serum hormone testing to rule out suprasellar involvement and subclinical pituitary dysfunction.
Chronic adrenal insufficiency presents with nonspecific symptoms in older adults. The diagnosis should be suspected in older people presenting with declining functional status and vague symptoms, even when hyperkalemia and orthostatic hypotension are absent.
Older people treated with 10 mg/day of prednisone for more than 3 months have a markedly increased risk of hip and vertebral fractures. Pharmacotherapy to prevent fractures should begin as soon as corticosteroids are started.
There is little evidence of long-term clinical benefit from supplementation with dehydroepiandrosterone (DHEA), testosterone, and growth hormone (GH) in older adults.
When adrenal incidentalomas are identified, consider restricting screening for corticosteroid excess and consideration of adrenalectomy to younger patients and those with a symptom complex suggesting Cushing syndrome.
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PRINCIPLES OF GERIATRIC ENDOCRINOLOGY
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Impaired Homeostatic Regulation
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As in other organ systems, the normal aging of the endocrine system is characterized by a progressive loss of reserve capacity, resulting in a decreased ability to adapt to changing environmental demands. This loss of homeostatic regulation reflects important alterations in hormonal synthesis, metabolism, and action, but these changes may not be clinically apparent under baseline conditions. In fact, basal plasma concentrations of many hormones and metabolic fuels are essentially unchanged with normal aging. This is illustrated by fasting plasma glucose levels that exhibit little change with normal aging, but after a glucose challenge, glucose levels increase much more in healthy older persons as compared to young adults. In some instances, the function of aging endocrine systems is maintained by compensatory changes in secretion of one hormone to offset ...