Table 2. Clinical characteristics and PSG parameters at initial and follow-up examinations within the surgical treatment and untreated groups

Variables	1st PSG	2nd PSG	p-value†
Surgical treatment group (n=31)
Age (yr)	40.0±9.1	43.4±10.5	0.000*
BMI (kg/m2)	29.0±5.1	29.5±4.4	0.109
AHI (/hr)	53.3±28.6	46.1±27.1	0.291
Min O2 sat (%)	73.9±9.4	77.2±7.3	0.058
LAD (s)	50.2±23.4	43.8±22.9	0.144
ESS	10.3±4.9	7.1±4.1	0.004*
PSQI	7.2±2.3	6.3±2.9	0.151
Untreated group (n=43)
Age (yr)	50.6±12.0	53.7±12.4	0.000*
BMI (kg/m2)	27.4±5.4	27.0±4.6	0.357
AHI (/hr)	44.6±28.6	45.1±29.8	0.904
Min O2 sat (%)	76.3±9.1	78.4±8.4	0.070
LAD (s)	53.4±26.8	41.0±24.0	0.007*
ESS	8.5±5.0	8.2±4.2	0.630
PSQI	9.0±3.7	8.0±3.0	0.109

p<0.05.
p-value was calculated by paired t-test comparing 1st PSG and 2nd PSG within each group.
PSG: polysomnography, BMI: body mass index, AHI: apnea-hypopnea index, Min O₂ sat: minimal O₂ saturation, LAD: longest apnea duration, ESS: Epworth sleepiness scale, PSQI: Pittsburgh sleep quality index.