Muscle wasting diseases has two distinct trajectories on the 3-dimensional age-BMI-peak VO2 scatterplot

Aims

Frailty and sarcopenia are age-related morbid states, and a low body mass index (BMI) is a characteristic of frailty and cachexia. However, no common index for assessing these three muscle wasting states is available, making it difficult to understand the relationship among them. Peak oxygen uptake (peak VO₂), an index of life expectancy, may be a useful common index. Therefore, this study aimed to investigate the relationship among sarcopenia, frailty, and cachexia using age, BMI, and peak VO₂.

Methods and Results

Participants were 175 Japanese community dwelling older adults (58 men, 117 women; 77.6 years). We assessed biochemical, physiological, and physical factors, and symptoms associated with frailty, and cachexia. Peak VO₂ was assessed with a cardiopulmonary exercise test. Participants were classified into five groups: robust, pre-frail, frail, sarcopenia, and cachexia. We compared the groups by age, BMI, and peakVO₂ with average values and 95% confidence intervals (CIs). 17% (n=30) of participants were classified as robust, 40% (n=70) as pre-frail, 12% (n=21) as sarcopenia, 25% (n=44) as frail, and 6% (n=10) as cachexia. Significant differences were found in age (robust vs. frail, pre-frail vs. frail), BMI (robust vs. cachexia, pre-frail vs. cachexia, frail vs. cachexia), and peak VO₂ (robust vs. frail, robust vs. cachexia, pre-frail vs. cachexia) with average values and 95% CIs. Three dimensions among age, BMI and peak VO₂ revealed two trajectories (from robust to frailty via pre-frailty, and from robust to cachexia via sarcopenia) among muscle wasting diseases.

Conclusions

This study revealed two trajectories among muscle wasting diseases.