Peak oxygen uptake correlates with indices of sarcopenia, frailty, and cachexia in older Japanese outpatients

Abstract

Background

Peak oxygen uptake (peak VO₂) is known not only as an index of aerobic fitness but also one of an index of life expectancy. Frailty, sarcopenia, and cachexia are associated with a poor prognosis and high mortality. The purpose of this study was to determine the relationships of peak VO₂ with the features of sarcopenia, frailty, and cachexia, to provide insight into which might mediate the poor prognosis.

Methods

The first group of participants was 175 community-dwelling older Japanese outpatients (58 men and 117 women; mean age 77.6 ± 6.4 years), in whom we assessed the features of sarcopenia, frailty, and cachexia, and measured peak VO₂ during cardiopulmonary exercise. To confirm the relationships, we analysed another group of 162 participants (77.3 ± 5.5 years).

Results

There were significant correlations between peak VO₂ and the features of sarcopenia, frailty, and cachexia, with the exception of high sensitivity C-reactive protein. Multiple linear regression analysis for the prediction of peak VO₂ (mL/min) identified following formula: predicted peak VO₂ = −11.6 × age (years) + 25.5 × haemoglobin concentration (g/dL) + 114.2 × skeletal muscle mass index (kg/m²) + 8.9 × hand grip strength (kg) + 226.4 × usual walking speed (m/s) − 65.8 × fatiguability (absence 0, presence 1) − 177.4 × chronic heart failure (absence 0, presence 1) + 437.1 (R² = 0.627, P < 0.001). The validity of the formula was confirmed with another group (r = 0.78, P < 0.001).

Conclusions

This study has identified the features of sarcopenia, frailty, and cachexia that are related to peak VO₂ in an older population.