Figure 2.
Correlations between the levels of GDF11 and physical activity.
Notes: Correlations between the levels of plasma GDF11 and parameters of physical activity including the number of steps (A), duration of ≥2.0 METs (B), ≥2.5 METs (C), and ≥3.0 METs (D) were investigated. r is the correlation coefficient. Data were statistically analyzed by the Spearman’s rank test. Closed circles (gray): GOLD stage I/II; closed circles (black): GOLD stage III/IV.
Abbreviations: GDF11, growth differentiation factor 11; GOLD, Global Initiative for Chronic Obstructive Lung Disease; METs, metabolic equivalents.