Table 3.

Linear regression analysis of bone mineral density in the patients with COPD (N=30)

Variables	Lumbar spine BMD			Total hip BMD			Femoral neck BMD
	β	t	P-value	β	t	P-value	β	t	P-value
Age, years	−0.050	−0.310	0.759	−0.006	−0.044	0.966	0.131	0.878	0.396
FEV1, %	0.121	0.734	0.471	−0.074	−0.539	0.596	−0.177	−1.166	0.259
BMI, kg/m2	0.595	1.379	0.182	0.744	2.083	0.050	0.327	0.823	0.420
FFMI, kg/m2	0.100	0.222	0.826	−0.153	−0.409	0.688	0.247	0.595	0.558
CAT score	0.116	0.689	0.498	−0.121	−0.872	0.393	−0.384	−2.486	0.021
DPA, cts·min−1	0.059	0.299	0.768	0.191	1.168	0.256	−0.058	−0.320	0.752

Notes: Lumbar spine BMD: adjust R²=0.360, F=3.247, P=0.017. Total hip BMD: adjust R²=0.561, F=6.112, P=0.001. Femoral neck BMD: adjust R²=0.457, F=4.366, P=0.004.

Abbreviations: BMD, bone mineral density; FEV₁, forced expiratory volume in 1 second; BMI, body mass index; FFMI, fat-free mass index; CAT, COPD assessment test; DPA, daily physical activity.