Table 2.

Correlation analysis of AHI and risk factors

Variables	BMI	Neck circumference	FEV1	FEV1% of expected value	FEV1 (%predicted) < 50%	CAT scores	ESS scores	SBQ scores	HADS-A scores	HADS-D scores	Hypertension	Coronary heart disease	Diabetes
r values	0.281	0.167	0.177	0.188	− 0.165	0.242	0.269	0.271	0.456	0.447	0.221	0.154	0.385
p values	< 0.001	0.001	< 0.001	< 0.001	0.001	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	0.001	0.035	< 0.001

BMI body mass index; FEV₁ forced expiratory volume in 1 s; CAT COPD assessment test; ESS Epworth sleepiness scale; SBQ STOP-Bang; HADS-A Hospital Anxiety and Depression Scale for anxiety; HADS-D Hospital Anxiety and Depression Scale for depression