Table 3

Prevalence ratios (95% CIs) of measures of sleep disordered breathing, sleep architecture, sleep fragmentation and sleep duration and coronary artery calcification prevalence (CAC >0): the Multi-Ethnic Study of Atherosclerosis 2010–2013*

		CAC >0
		Model 1		Model 2		Model 3
	1 SD	PR (95% CI)	p Value	PR (95% CI)	p Value	PR (95% CI)	p Value
Hypoxaemia and disordered breathing
Average oxygen saturation in sleep	1.7	0.96 (0.94 to 0.99)	0.005	0.98 (0.95 to 1.01)	0.12	0.98 (0.95 to 1.01)	0.25
Percentage sleep time SAO₂ <90%	8.6	1.03 (1.01 to 1.05)	0.004	1.02 (1.00 to 1.04)	0.05	1.02 (1.00 to 1.04)	0.13
Percentage time in apnoea + hypopnoea	12.4	1.05 (1.02 to 1.08)	0.001	1.03 (1.00 to 1.06)	0.03	1.03 (1.00 to 1.06)	0.04
Apnoea/hypopnoea events per night	109	1.05 (1.02 to 1.07)	0.001	1.03 (1.00 to 1.06)	0.02	1.03 (1.00 to 1.05)	0.07
AHI (continuously measured)	16.5	1.05 (1.02 to 1.08)	<0.001	1.04 (1.01 to 1.07)	0.01	1.03 (1.00 to 1.06)	0.03
Sleep architecture
Percentage time in stage N3	9.0	1.00 (0.96 to 1.04)	0.94	1.00 (0.97 to 1.04)	0.93	1.00 (0.97 to 1.04)	0.83
Sleep fragmentation
Arousal index	12.0	1.02 (0.99 to 1.06)	0.10	1.02 (0.99 to 1.05)	0.26	1.02 (0.99 to 1.05)	0.25
Arousal index—REM	11.8	1.03 (1.00 to 1.06)	0.05	1.02 (0.99 to 1.06)	0.13	1.02 (1.00 to 1.06)	0.10
Arousal index—NREM	12.8	1.02 (0.99 to 1.05)	0.11	1.02 (0.99 to 1.05)	0.25	1.02 (0.99 to 1.04)	0.26
Average sleep efficiency, %	3.5	0.98 (0.95 to 1.01)	0.18	0.98 (0.96 to 1.01)	0.24	0.98 (0.95 to 1.01)	0.20
Average sleep WASO	16.7	1.01 (0.98 to 1.04)	0.44	1.01 (0.98 to 1.04)	0.38	1.01 (0.98 to 1.04)	0.47
Sleep duration
399–444 min		Ref		Ref		Ref
<399 min		1.04 (0.96 to 1.12)	0.37	1.02 (0.94 to 1.11)	0.59	1.03 (0.95 to 1.11)	0.46
>444 min		0.99 (0.91 to 1.09)	0.88	0.99 (0.91 to 1.08)	0.83	0.98 (0.90 to 1.07)	0.71
3 degrees of freedom test			0.47		0.71		0.46

*All continuous variables have PR expressed per SD increment. Only 1390 observations were present for certain measures based on actigraphy (ie, sleep efficiency, WASO and sleep duration).
Model 1: adjusted for age, race/ethnicity, sex, centre, education (<high school, high school or some college, college degree or higher), income (<US$20 K, US$20 K to <US$50 K, ≥US$50 K) and smoking status (current, former, never).
Model 2: adjusted for model 1 + BMI.
Model 3: adjusted for model 2 + traditional CVD risk factors (prevalent diabetes, systolic blood pressure, hypertension medication use, HDL-C, LDL-C, use of lipid-lowering medications).
AHI, Apnea-Hypopnea Index; BMI, body mass index; CVD, cardiovascular disease; PR, prevalence ratio; SAO₂, oxygen saturation; WASO, time wake after sleep onset.