Table 1.

Characteristics of the enrolled patients (x̅±s)

Group	Case	Height (cm)	Weight (kg)	Age (years)	Time of smoking years 5-10; 11-15; 15-20; 20+				Stages of COPD mild moderate
Observation group	15	169.70±2.62	66.34±3.80	55.53±4.58	2	2	7	4	9	6
Control group	15	171.31±2.73	67.37±3.51	57.20±5.22	1	4	6	4	8	7

Note: General information of the patients of the two groups, P>0.05.