Fig. 4

Mediated analysis model path diagram.Notes: Body mass index was defined as the independent variable; Low bone mass disorders as the dependent variable; and NHHR as the mediating variable. Path a represents the regression coefficient of the association between BMI and NHHR. Path b represents the regression coefficient of the association between NHHR and Low bone mass disorders. Path c represents the simple total effect of NHHR on Low bone mass disorders. Path c’ represents the direct effect of BMI on Low bone mass disorders when controlling for NHHR.