Whole-Body versus Local DXA-Scan for the Diagnosis of Osteoporosis in COPD Patients

Table 1

Patients characteristics.

	Total group ($N=168$)	Men ($N=103$)	Women ($N=65$)	$P$-value
Age, years	63.6$\pm$9.1 (39–85)	65.9$\pm$8.6	60.0$\pm$8.7	$<$ .001
FEV1, $\%$predicted	44.3$\pm$18.5	45.06$\pm$18.1	43.12$\pm$19.2	.0510
GOLD I, $\%$	6.0	6.8	4.6	.402
GOLD II, $\%$	24.6	24.3	26.2
GOLD III, $\%$	26.3	30.1	20.0
GOLD IV, $\%$	43.1	38.8	49.2
Arterial blood gas
pH	7.43$\pm$0.03	7.44$\pm$0.03	7.43$\pm$0.03	.078
${\text{PaCO}}_2$, kPa	5.4$\pm$0.8	5.4$\pm$0.9	5.6$\pm$0.7	.106
${\text{PaO}}_2$, kPa	9.5$\pm$1.4	9.5$\pm$1.5	9.4$\pm$1.3	.466
${\text{SO}}_2\text{,}$$\%$	95$\pm$3	94$\pm$3	95$\pm$2	.536
Smoking
Ex-Smoker*, %	66.7	71.8	58.5	.073
Pack Years	38.8$\pm$15.5	38.9$\pm$15.0	38.8$\pm$1603	.960
BMI, $\text{kg}/{\text{m}}^2$	24.7$\pm$4.4	24.7$\pm$4.4	24.7$\pm$4.5	.960
Low, $\%$	20.8	21.4	20.0	.561
Normal, $\%$	30.4	33.0	26.2
High, $\%\mathrm{\hspace{0.17em}\hspace{0.17em}}$	38.1	34.0	44.6
Obese, $\%$	10.7	11.7	9.2
FFMI, $\text{kg}/{\text{m}}^2$	16.1$\pm$2.1	16.8$\pm$2.0	15.1$\pm$1.8	$<$ .001
Normal/Low, $\%$	58.9/41.1	61.2/38.8	55.4/44.6	.458
Whole body DXA
BMD, $\text{g}/{\text{cm}}^2$	1.079$\pm$0.118	1.113$\pm$0.114	1.025$\pm$0.103	$<$ .001
T-score	$-$1.3$\pm$1.4	$-$1.3$\pm$1.4	$-$1.3$\pm$1.3	.762
Normal BMD, $\%$	40.5	41.7	38.5	.075
Osteopenia, $\%$	36.9	31.1	46.2	.217
Osteoporosis, $\%$	22.6	27.2	15.4	.081
DXA hip
BMD, $\text{g}/{\text{cm}}^2$	0.827$\pm$0.149	0.858$\pm$0.146	0.779$\pm$0.143	.001
T-score	$-$1.7$\pm$1.1	$-$1.6$\pm$1.1	$-$1.9$\pm$1.0	.151
Normal BMD, $\%$	22.6	25.2	18.5	.400
Osteopenia, $\%$	52.4	53.4	52.3
Osteoporosis, $\%$	25.0	21.4	29.2
DXA LS
BMD, $\text{g}/{\text{cm}}^2$	1.065$\pm$0.215	1.088$\pm$0.211	1.027$\pm$0.218	.074
T-score	$-$1.3$\pm$1.8	$-$1.2$\pm$1.8	$-$1.4$\pm$1.8	.471
Normal BMD, $\%$	39.3	44.7	30.8	.198
Osteopenia, $\%$	33.3	30.1	38.5
Osteoporosis, $\%$	27.4	25.2	30.8
DXA hip and LS
Normal BMD, $\%$	15.5	19.4	10.8	.175
Osteopenia, $\%$	45.8	46.6	43.1
Osteoporosis, $\%$	38.7	34.0	46.2
6MWD, m ($n=165$)	420.61$\pm$135.66	454.41$\pm$132.57	368.62$\pm$124.28	$<$ .001
Oral corticosteroids, $\%$	17,9	18.4	16.9	.802
Daily dose^#, mg	5.9±2.1 (2.5–10)	6.1±2.1	5.7±2.3	.653
Inhaled	85.7$\%$	83.5	89.2	.301
corticosteroids, $\%$

Results are presented as means ± standard deviation, unless otherwise indicated.
*Rest of the patients are current smokers.
^#Only patients using oral corticosteroids on a daily base ($n=30$).
Abbreviations: FEV1 = forced expiratory volume in the first second; GOLD = Global Strategy for the Diagnosis, Management and prevention of COPD; COPD = chronic obstructive pulmonary disease; BMI = body mass index; FFMI = fat free mass index; DXA = dual energy absorptiometry; BMD = bone mineral density; LS = lumbar spine; 6MWD = six minutes walking distance; m = meters; PaCO₂ = arterial carbon dioxide tension; PaO₂ = Arterial oxygen tension; SO₂ = Oxygen saturation.