Unexplained Anemia of Aging

Etiology, Health Consequences, and Diagnostic Criteria

Jack Guralnik MD, PhD; William Ershler MD; Andrew Artz MD; Alejandro Lazo-Langner MD; Jeremy Walston MD; Marco Pahor MD; Luigi Ferrucci MD, PhD; William J. Evans PhD


J Am Geriatr Soc. 2022;70(3):891-899. 

In This Article

The Negative Effects of Anemia on Physical Function in Older People are Under-ascertained and Under-reported

Progressive, age-associated decreases in functional capacity, strength, and physical activity are well-described consequences of aging with multiple etiologies. Reduced hemoglobin is associated with low aerobic capacity, strength, and endurance in all adults, including older men and women.[26] Slower walking speed, an important biomarker of aging and prognostic of mortality and other adverse outcomes, is strongly associated with maximal aerobic capacity in older people.[27]

Functional capacity, in turn, is strongly associated with health-related outcomes in older men and women. In particular, the short physical performance battery (SPPB), a combined functional measurement of usual walking speed, time to stand up and sit down from a chair five times, and standing balance, is a powerful predictor of disability, institutionalization, and death.[28,29] Usual walking speed, one of the components of the SPPB, is strongly and independently associated with health-related outcomes and mortality risk.[30] This simple assessment is so strongly linked to health-related outcomes in geriatric patients that it has been termed the "sixth vital sign."[31] The SPPB (or usual walking speed) can be easily measured in a limited amount of space with no requirement for specialized equipment. In addition, the Functional Assessment of Chronic Illness Therapy (FACIT) is a brief, standardized set of 13 questions[32] that can identify functional differences between patients with or without anemia.

Although these measurements are strongly linked to outcomes, they are not commonly assessed in geriatric patients. Perhaps because these functional tests are not a routine component of a geriatric assessment by most health care providers, decreases in function are not often recognized and, as a result, lower Hb levels in geriatric patients may be considered inconsequential, with little effect on functional status or quality of life. We strongly recommend the routine use of a standardized assessment of functional capacity and fatigue during routine office visits so that such deficits may be quickly identified, and appropriate therapies may be implemented. However, current treatment options for UAA are extremely limited. By definition, the etiology of UAA is not understood and traditional treatment options such as iron, folate, B12, or improved nutrition often have little or no effect on resolving the anemia. The use of erythropoietin stimulating agents may be effective, but are generally used only for severe anemia, and even then only rarely.