Relationships of cardiac, pulmonary, and muscle reserves and frailty to exercise capacity in older women.

Published

Journal Article

BACKGROUND: A decline in exercise capacity (EC) is a characteristic of frailty. We hypothesized that decline is the effect of decrements in several physiological systems. We assessed whether the relationship of three main physiological systems-cardiac, pulmonary, and musculoskeletal-to EC is independent or interactive and whether their effect on EC varies with respect to frailty status. METHODS: Observational study of 547 disabled women aged 65 years and older (Women's Health and Aging Study I) including 131 frail who participated in a test of EC. EC (seated step test), cardiac function (chronotropic index), pulmonary function (forced vital capacity, FVC), musculoskeletal function (quadriceps strength, QS), and frailty status were measured and interactive effects were modeled using linear regression and differentiation. RESULTS: Each physiological system had a direct relationship with EC, which was lower in frail compared with nonfrail. The relationship between FVC and EC was positive and increased with increasing QS in nonfrail subjects. The effect of QS on EC was positive and increased with increasing FVC regardless of frailty. In subjects with low QS, frailty status was associated with lower EC and this effect became stronger with increasing FVC. Discussion Findings suggest but do not show that frailty status modifies the effects of physiological function in several systems on EC. Approaches to understanding emergent properties such as vulnerability to illness and death and clinical efforts to prevent and treat frailty should evaluate and possibly intervene on several physiological systems to be maximally effective.

Full Text

Duke Authors

Cited Authors

  • Weiss, CO; Hoenig, HH; Varadhan, R; Simonsick, EM; Fried, LP

Published Date

  • March 2010

Published In

Volume / Issue

  • 65 / 3

Start / End Page

  • 287 - 294

PubMed ID

  • 19822621

Pubmed Central ID

  • 19822621

Electronic International Standard Serial Number (EISSN)

  • 1758-535X

Digital Object Identifier (DOI)

  • 10.1093/gerona/glp147

Language

  • eng

Conference Location

  • United States