Functional capacity, physical activity, and quality of life in hypoxemic patients with chronic obstructive pulmonary disease

Figures & data

Table 1 Physical and demographic variables in hypoxemic and non-hypoxemic patients with COPD

Variables	Hypoxemic COPD	Non-hypoxemic COPD	P-value
Age (years)	62.83±7.37	59.95±8.83	0.335
Sex (male/female)	16/2	18/3	0.768
Height (cm)	167.59±6.40	167±5.59	0.839
Weight (kg)	71.00±13.41	75.44±12.91	0.322
Body mass index (kg/m^2)	25.88±3.60	27.31±5.24	0.338
Time from diagnosis (years)	6.89±4.70	8.61±7.56	0.791
Smoking (pack-years)	48.14±23.88	42.63±29.51	0.553
Number of doctor visits (n/year)	3.56±3.26	2.67±1.53	0.460
Number of emergency visits (n/year)	1.06±1.83	0.48±2.18	0.04*
Number of hospitalizations (n/year)	0.67±0.91	0.05±0.21	0.03*
pH	7.41±0.04	7.43±0.03	0.06
PaO2 (mmHg)	55.36±4.01	77.80±5.93	–
PaCO2 (mmHg)	43.26±7.90	35.68±3.02	<0.001**
SaO2 (%)	87.52±5.56	95.90±1.19	–
P(A-a)O2 (mmHg)	22.04±8.66	9.06±5.78	<0.001**
HCO3 (mEq/L)	26.70±4.21	23.20±2.61	0.001**
FEV1 (%)	36.67±12.91	62.62±23.50	<0.001**
FVC (%)	54.39±15.27	78.38±19.00	<0.001**
FEV6 (%)	52.00±13.49	80.13±18.80	<0.001**
FEV1/FVC	56.53±13.26	64.11±13.75	0.06
PEF (%)	45.06±15.24	65.90±28.87	0.03*
FEF25%–75% (%)	18.11±8.07	38.10±21.52	<0.001**

Notes: Values are expressed as mean ± standard deviation.

* P<0.05;

** P<0.001.

Abbreviations: COPD, chronic obstructive pulmonary disease; PaO₂, oxygen partial pressure; PaCO₂, carbon dioxide partial pressure; SaO₂, oxygen saturation; P(A-a)O₂, alveolar–arterial oxygen gradient; HCO₃, hydrogen bicarbonate; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; FEV₆, forced expiratory volume in 6 seconds; PEF, peak expiratory flow; FEF_25%–75%, forced expiratory flow between 25% and 75% of FVC.

Table 2 Functional capacity, physical activity, and quality of life in hypoxemic and non-hypoxemic patients with COPD

Variables	Hypoxemic COPD	Non-hypoxemic COPD	P-value
6MWT distance (m)	445.29±92.96	547.58±87.24	0.002*
%HRmax	78.84±7.49	68.79±11.66	0.007*
Borg-dyspnea (0–10)	3.72±3.06	2.19±2.79	0.073
Borg-fatigue (0–10)	2.64±2.54	2.64±2.33	0.989
SpO2 (%)	85.61±8.54	95.76±3.02	–
IPAQ total score (MET-min/week)	1,012.44±890.93	2,844.02±3,164.01	0.023*
IPAQ walking score (MET-min/week)	828.91±671.58	1,512.55±2,101.16	0.581
IPAQ moderate score (MET-min/week)	178.82±395.82	552.38±1,018.18	0.128
IPAQ vigorous score (MET-min/week)	4.71±19.40	779.05±2,400.65	0.467
IPAQ sitting score (min)	608.24±240.21	532.86±202.56	0.243
Energy expenditure (cals/day)	412.33±277.62	599.66±221.66	0.04*
SGRQ symptom score (0–100)	63.51±29.98	52.72±23.56	0.196
SGRQ activity score (0–100)	62.87±26.50	52.46±23.77	0.186
SGRQ impact score (0–100)	45.75±21.75	37.56±19.33	0.167
SGRQ total score (0–100)	53.96±22.55	44.73±19.64	0.158

Notes: Values are expressed as mean ± standard deviation.

* P<0.05.

Abbreviations: COPD, chronic obstructive pulmonary disease; 6MWT, 6-minute walk test; %HRmax, percentage of maximal heart rate; SpO₂, oxygen saturation with pulse oximeter; MET, metabolic equivalent; IPAQ, International Physical Activity Questionnaire; SGRQ, St George’s Respiratory Questionnaire.