Body Composition, Physical Function and Exercise Capacity in Chronic Obstructive Pulmonary Disease

Figures & data

Table 1. Descriptive characteristics of patients (n = 170 and 145).

Variable	Mean ± SD (n = 170)	Mean ± SD (n = 145)
Sex (n (% female))	80 (47%)	64 (44%)
Age (years)	66.0 ± 10.1	66.1 ± 9.6
BMI (kg/m^2)	27.7 ± 6.0	27.4 ± 5.9
Race/ethnicity
Non-Hispanic White	141	121
Non-Hispanic Black	28	24
Hispanic	1	0
Co-morbid illness (n (%with))
Arthritis	81 (48%)	71 (49%)
Hypertension	82 (48%)	69 (48%)
Heart Disease	78 (46%)	60 (41%)
Diabetes	21 (12%)	20 (14%)
Cancer	40 (24%)	38 (26%)
Total body mass (g)	82251.9 ± 19594.1	82113.2 ± 19384.8
Total body lean mass (g)	52495.4 ± 12214.5	52800.5 ± 12327.2
Total body fat bass (g)	27582.3 ± 10833.8	27115.8 ± 10456.3
Appendicular total mass (g)	36085.9 ± 8657.1	36007.5 ± 8346.4
Appendicular lean mass (g)	22566.3 ± 6076.2	22742.6 ± 6116.7
Appendicular fat mass (g)	12351.3 ± 4929.2	12079.9 ± 4613.5
FEV1 (% predicted)	51.8 ± 19.4	51.5 ± 19.2
FEV1/FVC (%)	51.5 ± 12.7	51.1 ± 12.9
V̇O2peak (ml/kg/min)		14.5 ± 4.1
Six-minute walk distance (m)	410.6 ± 128.0	420.6 ± 116.3
Physical function questionnaire (arbitrary units)	1.9 ± 0.6	2.0 ± 0.6

Abbreviations: SD, standard deviation; BMI, body mass index; FEV₁, forced expiratory volume in one second (expressed as a percent of predicted); FVC, forced vital capacity; FEV₁/FVC, ratio of the FEV₁ to the FVC; V̇O_2peak, peak oxygen consumption. Results of the physical function analyses, both objectively measured (6-minute walk distance) and self-report (Fitness Arthritis and Seniors Trial 23 item inventory) were derived from all 170 patients. Results of the exercise capacity analysis (V̇O_2peak) were derived from the 145 patient subset.

Table 2. Hierarchical regression analysis with V̇O_2peak as the dependent variable.

	B	95% CI for β	β	95% CI for β	p-value	ΔR^2
Constant	5.732	1.738 − 9.726			0.005
FEV1 % pred.	0.066	0.033 − 0.099	0.307	0.154 − 0.469	<0.001	0.063
Appendicular lean mass	0.000400	0.000222 − 0.000578	0.597	0.329 − 0.856	<0.001	0.123
Total body fat mass	−0.000175	−0.000255 to −0.000096	−0.447	−0.674 to −0.253	<0.001	0.198
Sex	2.435	0.296 −2.321	0.296	0.044 − 0.551	0.022	0.228

Note: B are the unstandardized regression coefficients. 95% CI for B are the 95% confidence intervals for the unstandardized regression coefficients. β are the standardized regression coefficients. 95% CI for β are the 95% confidence intervals for the standardized regression coefficients. ΔR² is the change in R² with the addition of each variable to the model.

Table 3. Hierarchical regression analysis with 6-minute walk distance as the dependent variable.

	B	95% CI for B	β	95% CI for β	p-value	ΔR^2
Constant	214.5	134.6 − 294.3			<0.001
FEV1 % pred.	1.0	0.063 − 1.965	0.154	0.009 − 0.298	0.037	0.041
Appendicular Lean Mass	0.006362	0.003321 − 0.009403	0.302	0.158 − 0.446	<0.001	0.130

Note: B are the unstandardized regression coefficients. 95% CI for B are the 95% confidence intervals for the unstandardized regression coefficients. β are the standardized regression coefficients. 95% CI for β are the 95% confidence intervals for the standardized regression coefficients. ΔR² is the change in R² with the addition of each variable to the model.

Table 4. Hierarchical regression analysis with physical function questionnaire as the dependent variable.

	B	95% CI for B	β	95% CI for β	p-value	ΔR^2
Constant	2.370	1.967 − 2.772			<0.001
FEV1 % pred.	0.001	−0.004 to 0.005	0.021	−0.131 to 0.173	0.783	0.009
Appendicular Lean Mass	−0.000018	−0.000034 to 0.000003	−0.186	−0.338 to −0.033	0.017	0.034

Note: B are the unstandardized regression coefficients. 95% CI for B are the 95% confidence intervals for the unstandardized regression coefficients. β are the standardized regression coefficients. 95% CI for β are the 95% confidence intervals for the standardized regression coefficients. ΔR² is the change in R² with the addition of each variable to the model.

Data availability statement

Data presented in this manuscript were obtained from patients who were reported on in a previously published manuscript [Berry et al. Respir Med. 2010 Jun; 104(6): 829–839. doi: 10.1016/j.rmed.2010.02.015].