Figure 5.

Relationship between (A) pre-flight biomarkers and change in total volumetric bone mineral density (Tt.vBMD) at the dominant tibia and (B) pre-flight running volume and change in trabecular vBMD (Tb.vBMD) and trabecular thickness (Tb.Th) at the dominant (left) and non-dominant (right) tibia. CTX, type I collagen C-terminal cross-linked telopeptide; P1NP, procollagen type 1 amino-terminal propeptide. Black circles are RAW change data for each crewmember. The line and shaded 95% CI represent the predicted relationship between change in bone variables and biomarker or running volume based on the mixed effects model (including fixed effects of mission duration, biomarker or running volume and interactions with time). Significant difference post-flight is indicated where CIs do not cross 0. Note: a change of 6 mg/cm³, 4 mg/cm³ and 0.005 mm for Tt.vBMD, Tb.vBMD and Tb.Th, respectively, is equivalent to a relative change of approximately 2%.