Table 3

Differences in ambulatory BP indices at 10-year follow-up (95% CI) by OSA status at baseline using normal as reference

BP parameters	Model	OSA status at baseline				P for interaction ‡
BP parameters	Model	Normal n=98 (40%)	Primary snoring n=49 (20%)	Mild OSA n=75 (31%)	Moderate/severe OSA n=21 (8.6%)	Sex	Age (baseline)	BMI (follow-up)	OAHI (follow-up)	ODI (follow-up)
SBP (mm Hg) (daytime)	1	Ref	0.0 (−3.0 to 3.6)	0.0 (−2.5 to 2.5)	1.6 (−1.9 to 5.2)	0.91	0.02*	0.74	0.49	0.09
	2	Ref	0.5 (−2.4 to 3.3)	0.4 (−1.9 to 2.8)	2.6 (−0.7 to 6.0)
	3	Ref	−0.1 (−3.1 to 2.8)	−0.1 (−2.5 to 2.4)	1.0 (−2.5 to 4.5)
	4	Ref	−0.2 (−3.3 to 2.9)	0.0 (−2.5 to 2.6)	1.6 (−2.3 to 5.6)
SBP (mm Hg) (night-time)	1	Ref	1.0 (−2.1 to 4.2)	−0.4 (−3.0 to 2.2)	6.5*** (2.9 to 0.1)	0.58	0.11	0.44	0.54	0.58
	2	Ref	1.3 (−1.8 to 4.3)	−0.2 (−2.7 to 2.3)	7.1*** (3.5 to 10.7)
	3	Ref	0.8 (−2.3 to 3.9)	−0.6 (−3.1 to 2.0)	6.0** (2.4 to 9.7)
	4	Ref	0.6 (−2.6 to 3.9)	−0.5 (−3.2 to 2.2)	7.0*** (2.9,11.1)
SBP (% dipping)	1	Ref	−0.9 (−2.9 to 1.0)	0.4 (−1.3 to 2.0)	−4.1*** (−6.3 to –1.8)	0.36	0.48	0.36	0.62	0.25
	2	Ref	−0.8 (−2.8 to 1.1)	0.4 (−1.2 to 2.1)	−3.8** (−6.1 to –1.5)
	3	Ref	−1.0 (−2.9 to 1.0)	0.3 (−1.3 to 2.0)	−4.8*** (−6.5 to –1.9)
	4	Ref	−0.8 (−3.0 to 1.3)	0.3 (−1.5 to 2.1)	−4.5** (−7.2 to –1.7)
DBP (mm Hg) (daytime)	1	Ref	0.9 (−1.3 to 3.2)	0.3 (−1.5 to 2.2)	−0.2 (−2.8 to 2.4)	0.73	0.06	0.34	0.46	0.30
	2	Ref	1.1 (−1.1 to 3.3)	0.5 (−1.3 to 2.3)	0.2 (−2.4 to 2.8)
	3	Ref	0.8 (−1.4 to 3.0)	0.3 (−1.5 to 2.1)	−0.6 (−3.1 to 2.0)
	4	Ref	0.7 (−1.6 to 3.1)	0.5 (−1.5 to 2.4)	1.0 (−2.0 to 3.9)
DBP (mm Hg) (night-time)	1	Ref	1.2 (−1.2 to 3.5)	−0.2 (−2.2 to 1.7)	1.8 (−1.0 to 4.5)	0.76	0.06	0.56	0.42	0.73
	2	Ref	1.3 (−1.0 to 3.7)	−0.1 (−2.0 to 1.9)	2.1 (−0.6 to 4.9)
	3	Ref	1.0 (−1.3 to 3.3)	−0.3 (−2.3 to 1.6)	1.3 (−1.4 to 4.1)
	4	Ref	1.0 (−1.5 to 3.4)	−0.5 (−2.5 to 1.6)	2.5 (−0.6 to 5.6)
DBP (% dipping)	1	Ref	−0.5 (−3.1 to 2.0)	0.8 (−1.3 to 2.9)	−2.6† (−5.6 to 0.3)	0.42	0.90	0.54	0.73	0.57
	2	Ref	−0.6 (−3.1 to 1.9)	0.7 (−1.4 to 2.8)	−2.7† (−5.7 to 0.3)
	3	Ref	−0.5 (−3.1 to 2.0)	0.8 (−1.3 to 2.9)	−2.6† (5.6 to 0.4)
	4	Ref	−0.6 (−3.2 to 2.1)	1.2 (−1.1 to 3.4)	−2.2 (−5.6 to 1.12)
MAP (mm Hg) (daytime)	1	Ref	0.5 (−1.6 to 2.6)	0.5 (−1.2 to 2.2)	0.7 (−1.8 to 3.1)	0.67	0.01*	0.28	0.75	0.11
	2	Ref	0.7 (−1.3 to 2.8)	0.7 (−0.9 to 2.4)	1.2 (−1.2 to 3.6)
	3	Ref	0.4 (−1.7 to 2.4)	0.4 (−1.3 to 2.1)	0.2 (−2.2 to 2.7)
	4	Ref	0.3 (−1.9 to 2.4)	0.6 (−1.2 to 2.4)	1.3 (−1.4 to 4.1)
MAP (mm Hg) (night-time)	1	Ref	0.5 (−1.7 to 2.8)	−0.2 (−2.1 to 1.7)	3.0* (0.4 to 5.6)	0.64	0.15	0.79	0.64	0.76
	2	Ref	0.7 (−1.5 to 2.9)	−0.1 (−1.9 to 1.8)	to 3.4* (0.8 to 6.0)
	3	Ref	0.4 (−1.9 to 2.6)	−0.3 (−2.2 to 1.5)	2.6† (−0.0,5.2)
	4	Ref	0.4 (−2.0 to 2.7)	−0.4 (−2.3 to 1.6)	3.7* (0.7 to 6.6)
MAP (% dipping)	1	Ref	−0.2 (−2.2 to .8)	0.8 (−0.8 to 2.5)	−2.7* (−5.0 to –0.3)	0.29	0.45	0.28	0.93	0.34
	2	Ref	−0.2 (−2.2 to 1.8)	0.9 (−0.8 to 2.5)	−2.6* (−5.0 to –0.3)
	3	Ref	−0.2 (−2.3 to 1.8)	0.8 (−0.9 to 2.5)	−2.7* (−5.1 to –0.4)
	4	Ref	−0.2 (−2.4 to 1.9)	1.0 (−0.8 to 2.8)	−2.8* (−5.5 to –0.1)

Model 1 adjusted for sex, age, BMI at baseline and height at baseline, height at follow-up and parental self-reported hypertension (either parent vs none).
Model 2 adjusted for all variables in model 1 plus BMI at follow-up.
Model 3 adjusted for all variables in model 1 plus OAHI at follow-up.
Model 4 adjusted for all variables in model 1 plus ODI at follow-up.
*P<0.05, **P<0.01, ***P<0.001.
†P<0.10.
‡Interaction term of log-transformed OAHI with variable undertested.
BMI, Body Mass Index; BP, Blood Pressure; DBP, Diastolic Blood Pressure; MAP, Mean Arterial Pressure; OAHI, Obstructive Apnoea–Hypopnoea Index; ODI, Oxygen Desaturation Index; OSA, Obstructive Sleep Apnoea; Ref, Reference; SBP, Systolic Blood Pressure.