African Americans and Men with Severe COPD Have a High Prevalence of Osteoporosis

Figures & data

Table 1 Variables and point values used for the computation of the modified BODE score

	Points on M-BODE Index
Variable	0	1	2	3
FEV1%	≥ 65	50–64	36–49	≤ 35
6 MWD (m)	≥ 350	250–349	150–249	≤ 149
Borg Scale	0–1	2–4	5–7	8–10
BMI (kg/m^2)	> 21	≤ 21

FEV₁: forced expiratory volume in the first second.

6 MWD: Six-minute walking distance.

BMI: Body Mass Index.

Table 2 Characteristics of study subjects by race and gender

	All	Caucasian	African American	Female	Male
N	179	132	39	98	81
Age (years)	59.5 ± 7.1	60.04 ± 6.7	58.4 ± 8.3	59.4 ± 7.5	59.6 ± 6.7
Weight (lbs)	156 ± 425	152.8 ± 36.3	166.5 ± 58.86	143.1 ± 32.1^†	171.7 ± 48.2^†
BMI (kg/m^2)	25.3 ± 5.3	25.0 ± 5.2	25.5 ± 5.5	24.9 ± 5.2	25.8 ± 5.5
Smoking (PY)	53 ± 32	58 ± 33^†	37 ± 23^†	49 ± 29	57 ± 35
Prednisone (%)^‡	45	46	38	42	47
FEV1 (L)	0.71 ± 0.30	0.71 ± 0.28	0.76 ± 0.36	0.599 ± 0.21^†	0.85 ± 0.33^†
FEV1%	26.0 ± 9.8	25.8 ± 9.1	27.6 ± 12.4	25.67 ± 8.84	26.5 ± 11.0
FVC (L)	2.38 ± 0.85	2.46 ± 0.89	2.21 ± 0.72	2.00 ± 0.66^†	2.85 ± 0.82^†
FVC%	65.39 ± 17.42	66.38 ± 17.45	62.28 ± 16.56	65.03 ± 17.06	65.65 ± 17.63
TLC%	123.1 ± 27.6	124.4 ± 29.6	119.3 ± 22.3	126.3 ± 26.03	119 ± 29.5
DLCO%	34.8 ± 19.8	35.7 ± 20.7	31.9 ± 17.5	30.6 ± 13.9	39.9 ± 24.4
RV (%)	222 ± 63	222 ± 59	217 ± 76	230 ± 59	214 ± 66
VO2 MAX%	38.4 ± 13.8	38.9 ± 13.2	37.0 ± 16.3	38.8 ± 12.6	38.0 ± 15.0
6 MWD (m)	253 ± 101	257 ± 92	243 ± 134	238.4 ± 93.73	271 ± 108
HgB (g/dl)	13.7 ± 1.5	13.8 ± 1.4	13.7 ± 1.6	13.3 ± 1.3^†	14.2 ± 1.5^†
M-BODE	6.25 ± 1.53	6.3 ± 1.55	6.13 ± 1.51	6.43 ± 1.58	6.04 ± 1.44
Fracture (%)	15	17	10	15	15

*p < 0.05 Between female and male.

^† p < 0.001 Between Caucasian and African American or female and male.

^†Percent of patients currently on prednisone.

TLC: total lung capacity.

DLCO: carbon monoxide lung diffusion capacity.

RV: residual volume.

PY: peak year.

FVC: forced expiratory vital capacity.

VO₂ MAX: is the maximum capacity to transport and utilize oxygen during incremental exercise.

Figure 1 The prevalence of osteoporosis was similar among males and females and fracture rate was not significantly different. The prevalence of osteoporosis was similar among African Americans and Caucasians (69.2% vs. 65.2%, p = 0.78).

Figure 2 Distribution of osteoporosis & osteopenia by site involved in all COPD patients (n = 179).

Table 3 Bone mineral density of subjects studied in all group and gender and race

	All	Caucasian	African American	Female	Male
LS BMD (g/cm^2)	0.803 ± 0.157	0.795 ± 0.156	0.828 ± 0.171	0.797 ± −0.167	0.812 ± 0.145
LS T Score	−2.6 ± −1.3	−2.55 ± −1.3	−3.02 ± −1.3	−2.5 ± −1.4	−2.8 ± −1.3
WT BMD (g/cm^2)	0.551 ± 0.191	0.532 ± 0.184	0.609 ± 0.204	0.545 ± 0.196	0.557 ± 0.185
WT T Score	−2.4 ± −0.97	−2.52 ± −0.96	−2.16 ± −0.91	−2.47 ± −1.1	−2.4 ± −0.86

* p < 0.05 Between Caucasian and African American.

LS: Lumbar spine.

WT: Ward's Triangle.

BMD: bone mineral density.

Figure 3 Correlations between WT T score and BMI in all COPD patients (n = 179).

Table 4 Univariate and multivariate analysis of risk factors by logistic regression among all COPD (N = 179) who were identified as having osteoporosis (T-score ≤ –2.5)

Univariate Analysis
		Odds Ratio Estimates
			95% Wald
Variable	p-value	Point Estimate	Confidence	Limits
Age (years)	0.542	1.014	0.970	1.059
Sex	0.255	1.441	0.769	2.699
Race	0.912	1.043	0.492	2.212
Weight (lbs)	0.07	0.993	0.985	1.001
BMI (kg/m^2)	0.0259	0.093	0.880	0.992
M-BODE	0.0604	1.220	0.991	1.501
6 MWD (m)	0.73	1.00	0.997	1.004
Smoking (peak year)	0.0918	2.379	0.991	1.010
Prednisone (%)	0.311	0.981	0.947	1.018
FEV1	0.275	0.564	0.201	1.579
FVC %	0.006	0.974	0.487	1.017
TLC %	0.916	1.001	0.989	1.012
VO2max%	0.0571	0.977	0.954	1.001
VO2maxIBX%	0.0779	0.981	0.961	1.002
Multivariate Analysis
FVC %	0.006	0.974	0.957	0.993

BMI: Body Mass Index.

6 MWD: Six-minute walking distance.

FEV₁: forced expiratory volume in the first second.

TLC: total lung capacity.

FVC: forced expiratory vital capacity.

RV: residual volume.

VO₂ MAX: is the maximum capacity to transport and utilize oxygen during incremental exercise.

Table 5 GOLD stage

GOLD Stage	% Osteoporosis	Fracture Rate	6 MWD (m)
Stage 2 (N = 7)	4 (57%)	0	237 ± 83
Stage 3 (N = 46)	25 (54%)	9 (20%)	287 ± 87
Stage 4 (N = 126)	86 (68%)	18 (14%)	242 ± 104

*p = 0.004 comparing Stage 3 to 4.

Stage2: FEV₁/FVC < 70%, 50% ≤ FEV₁ < 80%, with or without chronic symptoms(cough, sputum production).

Stage3: FEV₁/FVC < 70%, 30% ≤ FEV₁ < 50%, with or without chronic symptoms(cough, sputum production).

Stage4: FEV₁/FVC < 70%, FEV₁ < 30% predicted or FEV₁ < 50% predicted plus chronic respiratory failure.

Figure 4 Correlation between LS T score and modified M-BODE score.