Novel association between chronic obstructive pulmonary disease and osteoporosis: A prospective cross-sectional study

Table 2 Univariate analysis of forced expiratory volume in 1 second/forced vital capacity percentage, n (%)

Covariate	Statistics	β (95%CI)	P value
BMD, mg/cm3	99.1± 37.6	0.1 (0.1, 0.1)	< 0.0001
Low	140 (33.4)	Reference
Middle	139 (33.2)	2.0 (-1.8, 5.7)	0.3094
High	140 (33.4)	9.0 (5.3, 12.8)	< 0.0001
Sex
Male	290 (69)	Reference
Female	130 (31.0)	3.4 (0.0, 16.8)	0.0488
Age, years
Low	140 (29.4)	Reference
Middle	125 (29.4)	-8.9 (-12.8, -5.0)	< 0.0001
High	175 (41.2)	-19.5 (-40.2, 1.2)	0.0002
Height, cm
Low	140 (32.9)	Reference
Middle	140 (32.9)	0.3 (0.1, 0.3)	< 0.0001
High	145 (34.1)	0.5 (0.3, 0.8)	0.0028
Weight, kg	64.2± 10.6	0.9 (0.9, 1.0)	< 0.0001
Low	140 (32.9)	Reference
Middle	135 (31.8)	-0.9 (-4.8, 3.0)	0.6579
High	150 (35.3)	2.8 (-0.9, 6.5)	0.1383
BMI, kg/m2	23.2± 3.4	0.8 (0.3,1.3)	0.0006
Low	140 (32.9)	Reference
Middle	135 (31.8)	3.7 (-0.2, 7.6)	0.0669
High	150 (35.3)	3.8 (-0.1, 7.5)	0.0439
FEV1, L	2.0± 0.9	10.9 (9.7,12.1)	< 0.0001
Low	120 (32.4)	Reference
Middle	125 (33.8)	16.9 (14.2, 19.6)	< 0.0001
High	125 (33.8)	25.9 (23.2, 28.7)	< 0.0001
1Smoke
0	205 (48.8)	Reference
1	70 (16.7)	2.7 (-1.4, 6.8)	0.1950
2	145 (34.5)	-10.7 (-14.0, -7.4)	< 0.0001
Tea
Yes	270 (63.5)	Reference
No	155 (36.5)	4.1 (0.9, 7.4)	0.0135
2Physical activity
0	115 (27.1)	Reference
1	225 (52.9)	5.9 (2.4, 9.5)	0.0012
2	25 (5.9)	5.4 (-1.8, 12.6)	0.1395
3	60 (14.1)	-2.2 (-7.3, 2.8)	0.3856

¹Smoke: Smoking status: 0 = None, 1 = Current smoker, 2 = Former smoker.

²Physical activity: 0 = Sedentary; 1 = Normal activity; 2 = Regular exercise; 3 = Occasional exercise. BMD: Bone mineral density; BMI: Body mass index; CI: Confidence interval; FEV1: Forced expiratory volume in 1 second.