The effect of obesity on patients with mild chronic obstructive pulmonary disease: results from KNHANES 2010 to 2012

Figures & data

Figure 1 Flowchart for participants through the study.

Abbreviations: COPD, chronic obstructive pulmonary disease; FEV₁, forced expiratory volume in 1 s; FVC, forced vital capacity; KNHANES V, the 5th version of Korea National Health and Nutrition Examination Survey which was conducted during 2010–2012.

Table 1 Demographic information and comorbidities of obese and nonobese patients with COPD

Variable	Obese, (n=194)	Nonobese, (n=424)	P-value
Age (years)	61.8±0.8	64.2±0.6	0.03
Male	98.5	97.2	0.51
Height (cm)	166.7±0.6	166.4±0.3	0.68
Weight (kg)	74.8±0.6	61.3±0.4	<0.001
BMI (kg/m^2)	26.8±0.1	22.1±0.1	<0.001
Waist circumference (cm)	93.5±0.5	82.1±0.4	<0.001
Smoking
Current smoker	38.7	49.9	0.04
Former smoker	61.2	50.0
Smoking pack-years	36.7±1.7	34.3±1.1	0.25
Laboratory findings
Total cholesterol (mg/dL)	194.8±3.9	188.5±2.3	0.18
Triglycerides (mg/dL)	184.0±10.8	159.4±11.3	0.04
Fasting plasma glucose (mg/dL)	107.2±2.4	101.1±1.1	0.02
Metabolic syndrome	45.1	7.1	<0.001
Comorbid conditions
Hypertension	64.8	51.9	0.02
Diabetes mellitus	22.6	17.4	0.21
Dyslipidemia	78.4	78.1	0.93
Coronary artery disease	5.8	2.9	0.21
Stroke	2.6	2.1	0.69
Chronic renal failure	0.3	0.8	0.27
Osteoporosis	16.7	15.2	0.71
Osteoarthritis	14.0	10.2	0.27
Rheumatoid arthritis	0.6	1.3	0.44
Atopic dermatitis	2.3	3.9	0.44
History of lung cancer	0.2	0.1	0.96
History of pulmonary tuberculosis	7.8	15.6	0.05
Depression	10.4	8.1	0.45
Number of comorbidities	2.3±0.1	2.0±0.1	0.02

Note: Data presented as mean ± SE or percentage.

Abbreviations: BMI, body mass index; COPD, chronic obstructive pulmonary disease; SE, standard error.

Table 2 Symptoms and unadjusted pulmonary function of obese and nonobese patients with COPD

Variable	Obese, (n=194)	Nonobese, (n=424)	P-value
Symptom and quality of life
Wheezing	12.6	7.6	0.14
EQ-5D index	0.92±0.01	0.93±0.00	0.45
Spirometry
FEV1, L	2.55±0.05	2.50±0.03	0.44
FEV1, % pred	78.70±1.12	79.81±0.86	0.43
FVC, L	3.98±0.08	3.96±0.04	0.82
FVC, % pred	88.98±1.20	93.08±0.75	0.01
FEV1/FVC	0.64±0.00	0.62±0.00	0.04

Note: Data presented as mean ± SE or percentage.

Abbreviations: COPD, chronic obstructive pulmonary disease; EQ-5D™, EuroQol five dimensions questionnaire; FEV₁, forced expiratory volume in 1 s; FVC, forced vital capacity; % pred, % of predicted value; QOL, quality of life; SE, standard error.

Figure 2 Adjusted lung function of obese and nonobese patients with COPD.

Notes: Adjusted by age, sex, height, smoking status, history of tuberculosis, and metabolic syndrome. (A) FEV₁%; (B) FVC%; (C) FEV₁/FVC.
Abbreviations: COPD, chronic obstructive pulmonary disease; CI, confidential interval; FVC, forced vital capacity; FEV₁, forced expiratory volume in 1 s.