High Bone Mineral Density of the Lumbar Spine Is Positively Associated with Breast Cancer

Table 2

Characterization of bone mineral density by menopausal status and diagnosis of breast cancer. Goiânia. Brazil. 2014–2017.

Variables	Total sample (n = 376)			Premenopausal (n = 175)			Postmenopausal (n = 201)
	Cases	Controls	p	Cases	Controls	p	Cases	Controls	p
	n = 142	n = 234		n = 69	n = 106		n = 73	n = 128
Lumbar spine. BMO (g/ cm^2)
Q1 (lower)	42 (29.6)	58 (24.8)	0.700	20 (29.0)	26 (24.5)	0.905	22 (30.1)	32 (25.0)	0.666
Q2	34 (23.9)	59 (25.2)		15 (21.7)	27 (25.5)		19 (26.0)	32 (25.0)
Q3	37 (26.1)	60 (25.6)		18 (26.1)	28 (26.4)		19 (26.0)	32 (25.0)
Q4 (highest)	29 (20.4)	57 (24.4)		16 (23.2)	25 (23.6)		13 (17.8)	32 (25.0)
Z-score (≤ -2.0)				1 (1.4)	1 (0.9)	>0.999
T-score (≤ -1.1)							44 (60.3)	69 (53.9)	0.460
Femoral neck. BMO (g/cm^2)
Q1 (lower)	55 (38.7)	59 (25.2)	0.051	24 (34.8)	26 (24.5)	0.428	31 (42.5)	33 (25.8)	0.100
Q2	31 (21.8)	59 (25.2)		19 (27.5)	28 (26.5)		12 (16.5)	31 (24.2)
Q3	29 (20.4)	58 (24.8)		13 (18.8)	26 (24.5)		16 (21.9)	32 (25.0)
Q4 (highest)	27 (19.0)	58 (24.8)		13 (18.8)	26 (24.5)		14 (19.2)	32 (25.0)
Z-score (≤ -2.0)				3 (4.3)	1 (0.9)	0.302
T-score (≤ -1.1)							8 (11.0)	4 (3.1)	0.032
Total femur. BMO (g/cm^2)
Q1 (lower)	49 (36.8)	56 (25.6)	0.167	29 (44.6)	26 (26.3)	0.071	20 (29.4)	30 (25.0)	0.806
Q2	29 (21.8)	54 (24.7)		15 (23.1)	24 (24.2)		14 (20.6)	30 (25.0)
Q3	28 (21.1)	55 (25.1)		9 (13.8)	25 (25.3)		19 (27.9)	30 (25.0)
Q4 (highest)	27 (20.3)	54 (24.7)		12 (18.5)	24 (24.2)		15 (22.1)	30 (25.0)
Z-score (≤ -2.0)				- - -	1 (1.0)	>0.999
T-score (≤ -1.1)							5 (7.4)	2 (1.7)	0.101

Continuous variables are presented as mean and standard deviation (SD). In the presence of normality, the Student’s t-test was used, and in its absence the Mann-Whitney test was used. The categorical variables are in absolute and relative values ​​n (%). Fisher’s exact test was applied with a significance level of 5%. Cut points were obtained by the quartile of bone mineral density (BMD) for lumbar spine, total femur, and femoral neck based on the control group of the total sample and stratified by menopausal status. Lumbar column in the total sample: Q1 (≤0.998), Q2 (0.999–1.103), Q3 (1.104–1.204), and Q4 (≥1.205); premenopausal: Q1 (≤1.091), Q2 (1.092–1.159), Q3 (1.160–1.250), and Q4 (≥1.251) and postmenopausal: Q1 (≤0.925), Q2 (0.926-1.030), Q3 (1.031-1.150), and Q4 (≥1.151). Femoral neck in the total sample: Q1 (≤0.860), Q2 (0.861–0.958), Q3 (0.959–1.044), and Q4 (≥1.045); premenopausal: Q1 (≤0.929), Q2 (0.930–1.010), Q3 (1.011–1.104), and Q4 (≥1.105) and postmenopausal: Q1 (≤0.839), Q2 (0.840–0.914), Q3 (0.915–0.992), and Q4 (≥0.993). Total femur in the total sample: Q1 (≤0.901), Q2 (0.902–0.985), Q3 (0.986–1.076) and Q4 (≥1.077); premenopausal: Q1 (≤0.943), Q2 (0.944–1.032), Q3 (1.033–1.125), and Q4 (≥1.126) and postmenopausal: Q1 (≤0.859), Q2 (0.860–0.948), Q3 (0.949–1.041), and Q4 (≥1.042). The sample consisted of 133 cases (65 pre- and 68 postmenopausal) and 219 controls (99 pre- and 120 postmenopausal).