Table 3 Multiple linear regression analyses showing the association between polysomnographic parameters and daytime blood pressure parameters before and after adjustment for possible confounders

Variable	WSBP		WDBP		WMAP
Variable	β (95%CI)	p Value	β (95%CI)	p Value	β (95%CI)	p Value
Log transformed AHI adjusted for
Age, gender, body height	1.14 (0.5 to 1.7)	<0.001	0.56 (0.2 to 0.9)	0.004	0.74 (0.4 to 1.1)	<0.001
Age, gender, body height, BMI, waist	0.58 (−0.01 to 1.2)	0.05	0.47 (0.1 to 0.9)	0.02	0.51 (0.1 to 0.9)	0.01
Log transformed ODI adjusted for
Age, gender, body height	1.32 (0.6 to 2.0)	<0.001	0.84 (0.4 to 1.3)	<0.001	1.03 (0.6 to 1.5)	<0.001
Age, gender, body height, BMI, waist	0.70 (0.03 to 1.4)	0.04	0.76 (0.3 to 1.2)	0.001	0.78 (0.3 to 1.2)	<0.001
Log transformed ArI adjusted for
Age, gender, body height	2.10 (0.3 to 3.9)	0.02	1.24 (0.1 to 2.4)	0.03	1.49 (0.3 to 2.7)	0.01
Age, gender, body height, BMI, waist	1.29 (−0.4 to 3.0)	0.13	1.07 (−0.1 to 2.2)	0.07	1.11 (−0.04 to 2.3)	0.06

AHI, apnoea–hypopnoea index; ArI, arousal index; β (SE), beta coefficient (standard error); BMI, body mass index; ODI, oxygen desaturation index; waist, waist circumference; WDBP, wake diastolic blood pressure; WMAP, wake mean arterial pressure; WSBP, wake systolic blood pressure.