Metabolomics-based analysis of plasma in postmenopausal women with normal bone mineral density, postmenopausal osteoporosis, and rheumatoid arthritis osteoporosis

Figures & data

Figure 1. Distribution of study participants.

Table 1. General information of the three groups (X±SD).

	N group	PMO group	RAOP group	F	p
Age (years)	56.23 ± 5.46	57.90 ± 5.87	58.23 ± 4.46	1.226	0.298
Age of menopause (years)	50.20 ± 3.16	50.27 ± 3.33	50.10 ± 2.48	0.023	0.977
Height (cm)	156.10 ± 4.63	154.48 ± 4.17	155.95 ± 4.96	1.132	0.327
Weight (kg)	62.62 ± 6.25	58.63 ± 7.81	58.75 ± 11.01	2.089	0.130
BMI (kg/m^2)	25.74 ± 2.79	24.54 ± 2.91	24.11 ± 4.07	1.951	0.148
TC (mmol/L)	4.948 ± 0.293	4.784 ± 0.381	4.880 ± 0.369	1.652	0.198
TG (mmol/L)	1.940 ± 0.129	1.979 ± 0.133	1.943 ± 0.142	0.771	0.466
LDL (mmol/L)	3.203 ± 0.223	3.162 ± 0.259	3.150 ± 0.235	0.408	0.666
HDL (mmol/L)	1.278 ± 0.149	1.302 ± 0.145	1.231 ± 0.140	1.908	0.155
Lumbar BMD (g/cm^2)	1.008 ± 0.109	0.729 ± 0.074*	0.755 ± 0.042*	111.701	<0.001
T value	−0.293 ± 0.950	−2.857 ± 0.731*	−2.670 ± 0.325*	119.263	<0.001
Femoral neck BMD (g/cm^2)	0.804 ± 0.072	0.616 ± 0.090*	0.656 ± 0.072*	57.148	<0.001
T value	−0.407 ± 0.652	−2.200 ± 0.739*	−1.93 ± 0.693*	65.118	<0.001
Hip BMD (g/cm^2)	0.955 ± 0.094	0.751 ± 0.090*	0.723 ± 0.093*	47.312	<0.001
T value	0.127 ± 0.730	−1.557 ± 0.743*	−1.890 ± 0.728*	57.986	<0.001

*Compared with the N group, the differences were statistically significant. Compared with the PMO group, the differences were statistically significant.

Figure 2. Univariate analysis: A. Classification of differential metabolites. B. The volcano plot of the PMO group vs the N group in positive ion mode. C. The volcano plot of the PMO group vs the N group in negative ion mode. D. The volcano plot of the RAOP group vs the N group in positive ion mode. E. The volcano plot of the RAOP group vs the N group in negative ion mode (Figure 1E). In B-E, the red circles indicate high expression, and the blue circles indicate low expression.

Figure 3. Multidimensional statistical analysis: A. PCA analysis of the PMO group vs the N group in positive ion mode. B. PCA analysis of the PMO group vs the N group in negative ion mode. C. PCA analysis of the RAOP group vs the N group in positive ion mode. D. PCA analysis of the RAOP group vs the N group in negative ion mode. E. PLS-DA analysis of the PMO group vs the N group in positive ion mode. F. PLS-DA analysis of the PMO group vs the N group in negative ion mode. G. PLS-DA analysis of the RAOP group vs the N group in positive ion mode. H. PLS-DA analysis of the RAOP group vs the N group in negative ion mode. I. OPLS-DA analysis of the PMO group vs the N group in positive ion mode. J. OPLS-DA analysis of the PMO group vs the N group in negative ion mode. K. OPLS-DA analysis of the RAOP group vs the N group in positive ion mode. L. OPLS-DA analysis of the RAOP group vs the N group in negative ion mode.

Figure 4. Differential metabolites between the PMO and N groups and those between the RAOP and N groups and comparison of differential metabolite levels among the three groups: A. The Wayne diagram of metabolite set 1 and metabolite set 2. B. Comparison of 2-hydroxy-3-methylbutyric acid levels among the three groups. C. Comparison of dihomo-gamma-linolenic acid levels among the three groups. D. Comparison of epsilon-caprolactam levels among the three groups. E. Comparison of L-leucine levels among the three groups. F. Comparison of L-phenylalanine levels among the three groups. G. Comparison of vanillin levels among the three groups. *p < 0.05, **p < 0.01, ***p < 0.001.

Figure 5. Diagnostic efficacy of the six metabolites. The ROC curves of 2-hydroxy-3-methyl butyric acid, dihomo-gamma-linolenic acid, epsilon-caprolactam, L-leucine, L-phenylalanine, vanillin, and the six metabolites combined.