Circulating semaphorin-4D and plexin-B1 levels in postmenopausal women with low bone mass: the 3-month effect of zoledronic acid, denosumab or teriparatide treatment

Figures & data

Table 1. Comparative baseline data of the study groups.

Variable	Control (n = 30)	Zoledronic acid (n = 30)	Denosumab (n = 30)	Teriparatide (n = 28)	p-value for trend between groups
Age (years)	64.6 ± 1.4	66.1 ± 1.9	66.4 ± 1.4	65.4 ± 1.5	0.857
Age at menopause (years)	49.7 ± 0.7	48.3 ± 0.9	49.0 ± 0.9	47.8 ± 1.0	0.428
BMI (kg/m^2)	30.38 ± 0.95	28.05 ± 1.05	29.93 ± 0.61	28.98 ± 0.87	0.247
LS BMD (g/cm^2)	1.101 ± 0.024	0.921 ± 0.023*	0.925 ± 0.029*	0.839 ± 0.018*	< 0.001
LS T-score (SD)	-0.65 ± 0.20	-2.23 ± 0.18*	-2.17 ± 0.21*	-2.82 ± 0.12*	< 0.001
FN BMD (g/cm^2)	0.880 ± 0.016	0.704 ± 0.036*	0.751 ± 0.020*	0.660 ± 0.044*	0.002
FN T-score (SD)	-1.27 ± 0.11	-3.05 ± 0.30*	-2.62 ± 0.16*	-3.39 ± 0.34*	< 0.001
Previous BP treatment; n (%)	0 (0)	8 (27)*	3 (10)	14 (50)*^,§	< 0.001
Low-energy fractures; n (%)	0 (0)	4 (13)*	7 (23)*	13 (46)*^,‡	< 0.001
Current smoking; n (%)	3 (10)	2 (7)	6 (20)	9 (32)	0.057

Data are presented as mean ± standard error of the mean (SEM) or absolute numbers (%).

*Compared to control group.

^‡Compared to zoledronic acid group.

^§Compared to denosumab group (Tukey’s post-hoc adjustment for between-group pairwise comparisons).

BMD: Bone mineral density; BMI: Body mass index; BP: Bisphosphonate; FN: Femoral neck; LS: Lumbar spine.

Table 2. Comparative baseline and 3-month biochemical data of the study groups.

Variable	Group	Baseline	Month 3	p-value within groups
sema4D (ng/ml)	Control	27.5 ± 3.1	19.7 ± 3.0	0.026
	Zoledronic acid	51.4 ± 7.1*	55.1 ± 6.2*	0.773
	Denosumab	11.1 ± 1.4^‡	17.0 ± 2.9^‡	0.026
	Teriparatide	58.3 ± 6.0*^,§	46.3 ± 5.6*^,§	0.013
p-value between groups		< 0.001	< 0.001
Plexin-B1 (ng/ml)	Control	4.9 ± 1.5	3.0 ± 1.1	0.223
	Zoledronic acid	2.5 ± 0.6	4.9 ± 1.6	0.102
	Denosumab	3.0 ± 1.3	1.5 ± 0.4	0.090
	Teriparatide	4.7 ± 0.4	3.3 ± 0.5	0.017
p-value between groups		0.300	0.113
sema4D/plexin-B1	Control	28.8 ± 6.2	22.4 ± 8.1	0.685
	Zoledronic acid	46.4 ± 9.9	65.5 ± 16.3	0.428
	Denosumab	16.6 ± 2.9^‡	58.2 ± 23.5	0.004
	Teriparatide	16.8 ± 3.2^‡	19.8 ± 2.8	0.362
p-value between groups		0.003	0.126
tALP (U/l)	Control	82.9 ± 3.8	82.6 ± 3.9	0.717
	Zoledronic acid	80.0 ± 4.2	62.2 ± 3.3*	< 0.001
	Denosumab	83.0 ± 3.9	54.4 ± 3.0*	< 0.001
	Teriparatide	63.4 ± 3.6*^,‡,§	74.4 ± 5.1*	0.002
p-value between groups		0.001	< 0.001
bALP (μg/l)	Control	19.4 ± 1.1	31.8 ± 3.2	0.001
	Zoledronic acid	28.4 ± 2.0*	21.4 ± 2.6*	< 0.001
	Denosumab	20.4 ± 1.2^‡	18.7 ± 2.4*	0.165
	Teriparatide	17.5 ± 1.9^‡	21.3 ± 1.4^§	0.005
p-value between groups		< 0.001	0.002
CTx (ng/ml)	Control	0.454 ± 0.026	0.440 ± 0.030	0.205
	Zoledronic acid	0.412 ± 0.042	0.128 ± 0.016*	< 0.001
	Denosumab	0.497 ± 0.028	0.100 ± 0.012*	< 0.001
	Teriparatide	0.433 ± 0.040	0.929 ± 0.130*^,‡,§	< 0.001
p-value between groups		0.346	< 0.001
PTH (pg/ml)	Control	35.1 ± 3.3	29.7 ± 1.8	0.073
	Zoledronic acid	24.9 ± 2.4*	30.9 ± 3.3	0.024
	Denosumab	32.3 ± 2.6	36.1 ± 4.6	0.558
	Teriparatide	19.8 ± 2.2*^,§	13.7 ± 1.9*^,‡,§	0.003
p-value between groups		< 0.001	< 0.001
25(OH)D (ng/ml)	Control	39.2 ± 2.2	28.6 ± 2.4	< 0.001
	Zoledronic acid	28.8 ± 2.2*	27.2 ± 1.6	0.496
	Denosumab	37.4 ± 1.9^‡	34.8 ± 2.0^‡	0.203
	Teriparatide	21.5 ± 1.9*^,§	32.7 ± 2.2	< 0.001
p-value between groups		< 0.001	0.030
Corrected calcium (mg/dl)	Control	9.2 ± 0.1	9.2 ± 0.1	0.721
	Zoledronic acid	9.2 ± 0.1	9.0 ± 0.1	0.001
	Denosumab	9.2 ± 0.1	9.0 ± 0.1	0.082
	Teriparatide	9.0 ± 0.1	9.2 ± 0.1	0.021
p-value for between groups		0.441	0.115
Phosphate (mg/dl)	Control	3.5 ± 0.1	3.5 ± 0.1	0.436
	Zoledronic acid	3.4 ± 0.1	3.3 ± 0.1	0.244
	Denosumab	3.5 ± 0.1	3.4 ± 0.1	0.141
	Teriparatide	3.6 ± 0.1	3.7 ± 0.1^‡	0.446
p-value for between groups		0.053	0.017
Creatinine (mg/dl)	Control	0.86 ± 0.02	0.87 ± 0.03	0.825
	Zoledronic acid	0.90 ± 0.02	0.90 ± 0.02	0.450
	Denosumab	0.84 ± 0.03	0.80 ± 0.03	0.277
	Teriparatide	0.82 ± 0.05	0.76 ± 0.04 ^‡	0.022
p-value for between groups		0.275	0.013

Data are presented as mean ± standard error of the mean (SEM).

*Compared to control group.

^‡Compared to zoledronic acid group.

^§Compared to denosumab group (Bonferroni post-hoc adjustment for between groups pairwise comparisons).

25(OH)D: 25-hydroxyvitamin D; bALP: Bone-specific alkaline phosphatase; CTx: Serum carboxyterminal telopeptide of type 1 collagen; PTH: Intact parathyroid hormone; Sema4D: Semaphorin-4D; tALP: Total alkaline phosphatase.

Table 3. Bivariate correlations at baseline between sema4D, plexin-B1 and their ratio with other study parameters in the sum of participants.

Variable	Sema4D (ng/ml)	Plexin-B1 (ng/ml)	Sema4D/plexin-B1
Age (years)	-0.031 (0.742)	-0.075 (0.421)	0.045 (0.628)
Age at menopause (years)	-0.175 (0.068)	-0.087 (0.363)	-0.001 (0.994)
BMI (kg/m^2)	0.004 (0.996)	-0.126 (0.176)	0.161 (0.083)
LS BMD (g/cm^2)	-0.191 (0.053)	-0.163 (0.099)	0.078 (0.434)
FN BMD (g/cm^2)	-0.229 (0.179)	-0.150 (0.383)	-0.027 (0.876)
tALP (U/l)	-0.137 (0.145)	-0.063 (0.506)	-0.045 (0.635)
bALP (μg/l)	-0.002 (0.981)	-0.060 (0.517)	0.032 (0.736)
CTx (ng/ml)	-0.282 (0.002)	0.040 (0.670)	-0.261 (0.005)
PTH (pg/ml)	-0.388 (< 0.001)	-0.066 (0.484)	-0.204 (0.029)
25(OH)D (ng/ml)	-0.316 (< 0.001)	-0.203 (0.030)	-0.012 (0.899)
Corrected calcium (mg/dl)	-0.060 (0.523)	-0.054 (0.564)	-0.012 (0.900)
Phosphate (mg/dl)	0.104 (0.264)	0.072 (0.441)	0.039 (0.675)
Creatinine (mg/dl)	0.193 (0.059)	-0.003 (0.978)	0.126 (0.221)
Plexin-B1 (ng/ml)	0.307 (0.001)	-	-
sema4D/plexin-B1	0.361 (0.001)	-0.767 (< 0.001)	-

Data are presented as Spearman’s coefficient of correlation; r_s (p-value).

25(OH)D: 25-hydroxyvitamin D; bALP: Bone-specific alkaline phosphatase; BMD: Bone mineral density; CTx: Serum carboxyterminal telopeptide of type 1 collagen; FN: Femoral neck; LS: Lumbar spine; PTH: Intact parathyroid hormone; Sema4D: Semaphorin-4D; tALP: Total alkaline phosphatase.

Table 4. Multiple linear regression analysis for independent associates of log(sema4D) (stepwise method)*.

Covariate	β coefficient	p-value	95% CI for B coefficient
Previous BP treatment^‡	0.243	0.016	0.047 to 0.438
Log(PTH) (pg/ml)	-0.626	0.001	-1.005 to -0.248
25(OH)D (ng/ml)	-0.007	0.033	-0.013 to -0.001

*Variables excluded from the analysis (non-independent associates) were group, previous low-energy fracture, current smoking, age at menopause, BMI, LS BMD, log(plexin-B1), CTx and creatinine.

^‡Naïve participants were rated as 0, whereas those previously on bisphosphonates were rated as 1.

25(OH)D: 25-hydroxyvitamin D; BMD: Bone mineral density; BMI: Body mass index; BP: Bisphosphonate; CTx: Serum carboxyterminal telopeptide of type 1 collagen; LS: Lumbar spinal; PTH: Intact parathyroid hormone.

Table 5. Multiple linear regression analysis for independent associates of log(plexin-B1) (stepwise method)*.

Covariate	β coefficient	p-value	95% CI for B coefficient
Previous BP treatment^‡	0.356	0.015	0.070 to 0.642
25(OH)D (ng/ml)	-0.012	0.018	-0.021 to -0.002
BMI (kg/m^2)	-0.029	0.032	-0.055 to -0.003

*Variables excluded from the analysis (non-independent associates) were group, previous low-energy fracture, current smoking, age at menopause, LS BMD, log(plexin-B1), PTH, CTx and creatinine.

^‡Naïve participants were rated as 0, whereas those previously on bisphosphonates were rated as 1.

25(OH)D: 25-hydroxyvitamin D; BMD: Bone mineral density; BMI: Body mass index; BP: Bisphosphonate; CTx: Serum carboxyterminal telopeptide of type 1 collagen; LS: Lumbar spinal; PTH: Intact parathyroid hormone.

Table 6. Partial correlations at month 3 between sema4D, plexin-B1 and their ratio with other study parameters, after adjustment for group in the sum of participants.

Variable	Sema4D (ng/ml)	Plexin-B1 (ng/ml)	Sema4D/plexin-B1
Age (years)	-0.016 (0.868)	0.127 (0.187)	0.078 (0.420)
Age at menopause (years)	-0.271 (0.005)	0.022 (0.828)	-0.055 (0.581)
BMI (kg/m^2)	-0.024 (0.804)	0.163 (0.091)	0.110 (0.254)
tALP (U/l)	0.087 (0.373)	0.145 (0.138)	-0.016 (0.872)
bALP (μg/l)	-0.025 (0.796)	0.026 (0.790)	0.263 (0.006)
CTx (ng/ml)	0.023 (0.814)	0.023 (0.813)	-0.143 (0.135)
PTH (pg/ml)	-0.281 (0.003)	0.022 (0.822)	-0.089 (0.363)
25(OH)D (ng/ml)	-0.190 (0.051)	-0.133 (0.175)	-0.072 (0.465)
Corrected calcium (mg/dl)	0.014 (0.885)	-0.049 (0.613)	0.022 (0.823)
Phosphate (mg/dl)	0.185 (0.057)	-0.065 (0.504)	0.034 (0.729)
Creatinine (mg/dl)	0.207 (0.043)	0.092 (0.374)	-0.148 (0.151)
Plexin-B1 (ng/ml)	0.121 (0.207)	-	-
Sema4D/plexin-B1	0.161 (0.094)	-0.223 (0.019)	-

Data are presented as coefficient of partial correlation; r_p (p-value).

25(OH)D: 25-hydroxyvitamin D; bALP: Bone-specific alkaline phosphatase; BMD: Bone mineral density; BMI: Body mass index; CTx: Serum carboxyterminal telopeptide of type 1 collagen; PTH: Intact parathyroid hormone; Sema4D: Semaphorin-4D; tALP: Total alkaline phosphatase.