Figure 4. Correlation of day7 changes in plasma and urinary levels of urea with changes in fat-free mass after bedrest.

Plot of the after-bedrest final change in fat-free mass over the day7 change in plasma urea (R = 0.566, P = 0.009) and in urinary urea (R = 0.715, P<0.001). The correlation coefficient for day7 change in plasma and urinary urea were significant also after exclusion of the case with fat-free mass change <4 kg (R = 0.554 and 0.640, P<0.01) and with control for baseline values of the variables (partial R = 0.608 and 0.684, P<0.01).