Table 4 Multiple linear regression analyses showing the association between polysomnographic parameters and nocturnal blood pressure parameters before and after adjustment for possible confounders
VariableSSBPSDBPSMAP
β (95%CI)p Valueβ (95%CI)p Valueβ (95%CI)p Value
Log transformed AHI adjusted for
    Age, gender, body height1.48 (0.9 to 2.1)<0.0010.61 (0.2 to 1.0)0.0050.87 (0.5 to 1.3)<0.001
    Age, gender, body height, BMI, waist1.13 (0.5 to 1.8)<0.0010.63 (0.2 to 1.1)0.0060.75 (0.3 to 1.2)<0.001
Log transformed ODI adjusted for
    Age, gender, body height1.02 (0.3 to 1.7)0.0060.30 (−0.2 to 0.8)0.250.59 (0.1 to 1.1)0.02
    Age, gender, body height, BMI, waist0.57 (−0.2 to 1.3)0.130.28 (−0.2 to 0.8)0.300.42 (−0.1 to 0.9)0.11
Log transformed ArI adjusted for
    Age, gender, body height3.06 (1.2 to 4.9)0.0011.88 (0.6 to 3.2)0.0042.10 (0.9 to 3.3)0.001
    Age, gender, body height, BMI, waist2.49 (0.7 to 4.3)0.0081.86 (0.5 to 3.1)0.0061.86 (0.6 to 3.1)0.004
  • AHI, apnoea-hypopnoea index; ArI, arousal index; β (SE), beta coefficient (standard error); BMI, body mass index; ODI, oxygen desaturation index; SDBP, sleep diastolic blood pressure; SMAP, sleep mean arterial pressure; SSBP, sleep systolic blood pressure; waist, waist circumference.