Risk factors of osteoporosis and osteopenia in postmenopausal women based on the L2–L4 BMD T score of the lumbar spine: a study in Iran

Figures & data

Table 1. Demographic and clinical characteristics of the study women.

N = 1,359
Age (year)	57.0 ± 7.4; (45–84)
Parity	4 (0–14)
Body mass index (BMI)	29.1 ± 4.2; (13.8–46.1)
Ethnicity
Persian	939 (69.1)
Turk	237 (17.4)
Kurd	140 (10.3)
Other	26 (1.9)
Unknown	17 (1.3)
Calcium D supplement
No	877 (62.3)
Yes	526 (37.4)
Unknown	4 (0.3)
Dairy use:
Low	884 (65.0)
Moderate to high	449 (33.0)
Unknown	26 (2.0)
Regular exercise
No	645 (47.5)
Yes
Menarche age	519 (38.2)
13.4 + 1.1; (9–18)
Nulliparity	53 (3.9)
Breastfeeding years	2.8 (0–21)
Diabetes	173 (12.7)
Renal failure	36(2.6)
Hypothyroidism	57 (4.2)
Hyperthyroidism	8 (0.6)
Previous fracture	196 (14.4)
Normal:	394 (29.0)
Osteopenic:	791 (58.2)
Osteoporotic:	174 (12.8)

Data are shown as mean (±SD; range) or median (range) or frequency (%).

Table 2. Risk factors for osteopenia or osteoporosis in postmenopausal women of the study.

	T Score (L2-L4): n (%)			p value
Characteristics (N)	Normal: 394 (29.0%)	Osteopenic: 791 (58.2%)	Osteoporotic: 174 (12.8%)	Overall	Normal versus osteopenic	Normal versus osteoporotic
Age (year)	54.0 + 6.0	57.3 + 7.1	62.1 + 8.1	<.001	<.001	<.001
Weight (kg)	75.1 + 9.7	70.3 + 9.9	63.5 + 11.1	<.001	<.001	<.001
Height (cm)	157.6 + 5.6	155.8 + 6.1	153.1 + 6.2	<.001	<.001	<.001
BMI	30.3 + 3.8	29.0 + 4.2	27.0 + 4.3	<.001	<.001	<.001
BMI:				<.001	<.001	<.001
<25 (222)	33 (14.9)	129 (58.1)	60 (27.0)
25–<30 (559)	154 (27.5)	340 (60.8)	65 (11.6)
= >30 (539)	197 (36.5)	300 (55.7)	42 (7.8)
Ethnicity:				.026	.432	.003
Persian (939)	283 (30.1)	551 (58.7)	105 (11.2)
Turk (237)	71 (30.0)	135 (57.0)	31 (13.0)
Kurd (140)	29 (20.7)	81 (57.9)	30 (21.4)
Others (26)	8 (30.8)	14 (53.8)	4 (15.4)
Dairy use:				.003	.002	.019
Low (884)	231 (26.1)	534 (60.4)	119 (13.5)
Moderate to high (449)	157 (35.0)	241 (53.7)	51 (11.4)
Calcium-D supplement:				.005	.002	.017
Yes (506)	173 (34.2)	275 (54.3)	58 (11.5)
No (850)	220 (25.9)	514 (60.5)	116 (13.6)
Regular exercise:				<.001	.010	<.001
Yes (519)	177 (34.1)	297 (57.2)	45 (8.7)
No (645)	162 (25.1)	383 (59.4)	100 (15.5)

Data are shown as mean ± SD or frequency (%); BMI: body mass index.

Table 3. The relation of clinical factors with osteopenia or osteoporosis.

	T Score (L2–L4) n (%)			p value
Characteristics (N)	Normal 426 (30.2%)	Osteopenic 801 (57.2%)	Osteoporotic 174 (12.4%)	Overall	Normal versus osteopenic	Normal versus osteoporotic
Menarche age	13.4 ± 1.2	13.4 ± 1.1	13.4 ± 0.9	.930	.937	.998
Parity:				<.001	<.001	<.001
0–2 (197)	65 (33.0)	110 (55.8)	22 (11.2)
3–5 (752)	257 (34.2)	429 (57.0)	66 (8.8)
= >6 (389)	67 (17.2)	238 (61.2)	84 (21.6)
Breastfeeding years:				.001	.183	<.001
0–2 (513)	148 (28.8)	299 (58.3)	66 (12.9)
>2–10 (623)	198 (31.8)	361 (57.9)	64 (10.3)
>10 (145)	30 (20.7)	83 (57.2)	32 (22.1)
Diabetes:				.108	.570	.036
Yes (173)	56 (32.4)	103 (59.5)	14 (8.1)
No (1,174)	334 (28.4)	680 (57.9)	160 (13.6)
Renal failure:				.978	.906	.784
Yes (36)	10 (27.8)	21 (58.3)	5 (13.9)
No (1,348)	407 (30.2)	772 (57.3)	169 (12.5)
Hypothyroidism:				.204	.781	.118
Yes (57)	17 (29.8)	37 (64.9)	3 (5.3)
No (1,291)	373 (28.9)	747 (57.9)	171 (13.2)
Hyperthyroidism:				.100	1.0	.090
Yes (8)	1 (12.5)	4 (50.0)	3 (37.5)
No (1,339)	389 (29.1)	779 (58.2)	171 (12.8)
Previous fracture:				.111	.187	.037
Yes (196)	47 (20.4)	117 (59.7)	32 (16.3)
No (1158)	345 (29.8)	673 (58.1)	140 (12.1)

Data are shown as mean ± SD and compare with one-way ANOVA; or frequency (percentage) and compare with chi square test.

Table 4. The crude and adjusted odds ratio of different categories of age and BMI for osteopenia and osteoporosis.

	Crude OR (95% CI; p value)		Adjusted OR (95% CI; p value)
Characteristics (N)	Osteopenic versus normal	Osteoporotic versus normal	Osteopenic versus normal	Osteoporotic versus normal
Age:	p < .001	p < .001	p < .001	p < .001
45–50	ref.	ref.	ref.	ref.
51–55	1.54 (1.12–2.13; p = .009)	5.01 (2.04–12.31; p < .001)	1.72 (1.19–2.48; p = .004)	4.53 (1.55–13.22; p = .006)
56–60	2.09 (1.47–2.98; p < .001)	10.91 (4.46–26.71; p < .001)	2.28 (1.51–3.43; p < .001)	11.36 (3.83–33.67; p < .001)
>60	4.45 (2.98–6.63; p < .001)	7.33 (15.28–91.20; p < .001)	4.16 (2.59–6.69; p < .001)	20.81 (6.96–62.20; p < .001)
BMI:	p < .001	p < .001	p < .001	p < .001
<25	2.57 (1.68–2.92; p < .001)	8.53 (4.97–14.63; p < .001)	2.87 (1.76–4.60; p < .001)	12.41 (5.68–27.12; p < .001)
25–<30	1.45 (1.12–1.88; p = .005)	1.98 (1.27–3.08; p = .002)	1.52 (1.12–2.05; p = .007)	3.06 (1.66–5.66; p < .001)
= >30	ref.	ref.	ref.	ref.

Table 5. The crude and adjusted odds ratio of predicting factors of osteopenia and osteoporosis.

	Crude OR (95% CI; P Value)		Adjusted OR (95% CI; P Value)
Characteristics (N)	Osteopenic versus normal	Osteoporotic versus normal	Osteopenic versus normal	Osteoporotic versus normal
Age (year)	1.08 (1.06–1.10; p < .001)	1.17 (1.14–1.21; p < .001)	1.08 (1.05–1.11; p < .001)	1.14 (1.09–1.19; p < .001)
BMI:	p < .001	p < .001	(p < .001)	(p < .001)
<25	ref.	ref.	ref.	ref.
25–<30	0.57 (0.37–0.87; p = .009)	0.23 (0.14–0.39; p < .001)	0.55 (0.34–0.88; p = .012)	0.28 (0.13–0.59; p = .001)
= >30	0.39 (0.26–0.59; p < .001)	0.12 (0.07–0.20; p < .001)	0.36 (0.28–0.58; p < .001)	0.09 (0.04–0.20; p < .001)
Parity:	p < .001	p < .001	p = .078	p = .002
0–2	ref.	ref.	ref.	ref.
3–5	0.98 (0.70–1.39; p = .938)	0.76 (0.44–1.32; p = .329)	1.01 (0.68–1.47; p = .988)	0.95 (0.42–2.15; p = .906)
= >6	2.10 (1.39–3.16; p < .001)	3.70 (2.07–6.62; p < .001)	1.52 (0.94–2.45; p = .085)	4.45 (1.69–11.74; p = .003)
Breastfeeding years:	–	p < .001		.813
0–2 (513)		ref.	ref.	ref.
>2–10 (623)		0.73 (0.48–1.09; p = .119)		0.81 (0.43–1.54; p = .520)
>10 (145)		2.39 (1.34–4.26; p = .003)		0.92 (0.36–2.32; p = .854)
Calcium-D supplement:
Yes	ref.	ref.	ref.	ref.
No	1.47 (1.15–1.88; p = .002)	1.57 (1.08–2.29; p = .017)	1.22 (0.91–1.63; p = .184)	0.92 (0.52–1.64; p = .780)
Regular exercise:
Yes	ref.	ref.	ref.	ref.
No	1.41 (1.09–1.83; p = .010)	2.43 (1.61–3.66; p < .001)	1.08 (0.80–1.47; p = .606)	2.22 (1.19–4.15; p = .012)
Dairy use:
Low	1.51 (1.17–1.94; p = .002)	1.59 (1.08–2.33; p = .019)	1.26 (0.93–1.72; p = .135)	0.78 (0.42–1.45; p = .427)
Moderate to high	ref.	ref.	ref.	ref.
Ethnicity:		p = .005		0.056
Persian	–	ref.	–	ref.
Turk	–	1.18 (0.73–1.90; p = .504)	–	1.06 (0.53–2.15; p = .867)
Kurd	–	2.79 (1.60–4.87; p < .001)	–	2.96 (1.31–6.67; p = .009)
Others	–	1.35 (0.40–4.57; p = .632)	–	0.39 (0.03–6.18; p = .507)
Diabetes:
Yes	–	0.52 (0.28–0.97; p = .038)	–	0.41 (0.18–0.95; p = .038)
No	–	ref.	–	ref.
Hyperthyroidism:
Yes	–	6.83 (0.71–66.08; p = .097)	–	23.43 (2.14–256.67; p = .001)
No	–	ref.	–	ref.
Previous fracture:
Yes	–	1.68 (1.03–2.74; p = .039)	–	2.15 (1.03–4.49; p = .041)
No	–	ref.	–	ref.

BMI, body mass index; OR, odds ratio; CI, confidence interval.