Women with previous stress fractures show reduced bone material strength

Figures & data

Table 1. Descriptive characteristics of the patients with stress fracture and controls without stress fractures

	Total n = 60	Stress fractures n = 30	No stress fractures n = 30	p-value
Age, years	41 (19)	39 (13.9)	42.3 (9.80)	0.3
range	19-66	19-64	23-66
Height, cm	169 (5)	167 (6)	169 (5)	0.7
Weight, kg	68.5 (12.20)	68.1 (15.00)	69.5 (10.50)	0.7
BMI	24.1 (3.90)	24.1 (5.10)	24.1 (3.30)	1.0
History of eating disorder, n	10	7	3	0.2
History of oligo-menorrhea/amenorrhea, n	12	9	3	0.05

Unless otherwise stated, values are mean (SD).

Independent t-test for means between groups and chi-squared test (for proportions).

Table 2. Distribution of stress fractures by site

Location	n
Foot	21
Metatarsal	13
Navicular	5
Sesamoid	2
Calcaneal	1
Femur	3
Tibia	3
Pelvis	2
Patella	1
Total	30

Figure 1. Lack of correlation between BMSi and bone mineral density (BMD, g/cm²) at the femoral neck in stress fracture patients and controls without stress fracture. Red – patients with stress fracture, and blue – controls.

Table 3. Regional BMD measured by DXA in the 2 groups. Values are mean (SD)

	Stress fractures n = 30	No stress fractures n = 30	p-value
BMD (g/cm^2)
Lumbar spine	1.14 (0.12)	1.22 (0.15)	0.005
Femoral neck	0.92 (0.25)	1.05 (0.11)	0.03
Total hip	0.99 (0.11)	1.04 (0.10)	0.1
BMD T-score
Lumbar spine	−0.5 (1.1)	0.6 (1.00)	0.001
Femoral neck	−0.2 (1.0)	0.3 (0.70)	0.03
Total hip	0.0 (1.10)	0.3 (0.80)	0.1

All p-values are based on t-test.

BMD: bone mineral density

Figure 2. Lack of correlation between BMSi and P1NP in patients with stress fracture and controls without stress fracture. Red – patients with stress fracture, and blue – controls.

Table 4. Serum biochemistry. Values are mean (SD)

	Stress fractures n = 30	No stress fractures n = 30	p-value	r
P1NP, μg/L	56 (23)	43 (17)	0.3	−0.110
CTX, μg/L	0.34 (0.18)	0.29 (0.18)	0.3	−0.028
B-ALP, μg/L	29 (16.5)	22.8 (7.90)	0.07	−0.055
Vitamin D, nmol/L	68 (27)	65 (32)	0.7	0.075
Osteocalcin, nmol/L	1.2 (0.90)	1.4 (1.00)	0.02	0.075
Calcium, nmol/L	1.21 (0.03)	1.23 (0.04)	0.3	−0.110
PTH, pmol/L	5.8 (8.00)	3.8 (1.60)	0.9	−0.030
Phosphate, mmol/L	1.07 (0.12)	1.06 (0.17)	1.0	−0.086

All p-values were obtained using independent-samples t-test.

r: coeffi cient for linear regression of variable on BMSi.

Reference ranges: P1NP, 11–94 (women >30 years); CTX, < 1.01 (menopausal), < 0.57: (pre-menopausal); B-ALP, 5.5–24.6; vitamin D, 37–131; osteocalcin, 1.5–5.4; calcium, 1.15–1.33; PTH, 1.5–7.0 (18–64 years), 1.4–8.6 (> 65 years); phosphate, 0.80–1.40.