The principal objective of the SHHS is to determine whether sleep-disordered breathing including obstructive sleep apnea is an independent risk factor for the development of cardiovascular and cerebrovascular disease.

Study investigators have identified both primary and secondary hypotheses to be tested in the SHHS. The primary hypotheses are the main focus of analyses conducted on the entire cohort and have driven the study design specifications and sample size calculations. Secondary hypotheses will be tested either on the entire cohort or on subsets of the cohort for whom appropriate covariate data exist.

The primary hypotheses to be tested are:

1. Sleep-disordered breathing (SDB) is associated with an increased risk of incident coronary heart disease (CHD) events.
2. SDB is associated with an increased risk of incident stroke.
3. SDB is associated longitudinally with increased blood pressure.
4. SDB is associated with an increased risk of all-cause mortality.

Secondary hypotheses, which will be tested on either the entire cohort or on subsets of the cohort for whom data are available, are:

1. SDB is associated with an increased risk of recurrent CHD.
2. SDB is associated with an increased risk of recurrent stroke.
3. SDB is associated with impairment of health-related quality of life.
4. SDB is associated with a more rapid decrease in health-related quality of life.
5. SDB is associated with increases in left ventricular mass.
6. SDB is associated with changes in carotid measurements.
7. SDB is associated with an increase in arrhythmias.
8. SDB is associated with an increase in neuropsychological deficits (e.g., in attention, executive functions, learning and memory, and information processing) and with adverse effects on mood (e.g., irritability, anxiety, and depression).
9. SDB is associated with increased sleepiness.
10. SDB is associated with hemostatic dysfunction that promotes hypercoagulation and thrombosis.
11. SDB is associated with a distinct circadian pattern of cardiovascular (CVD) event occurrence.
12. SDB is associated with increases in nocturnal blood pressure and/or increasing 24-hour hypertensive load.
13. Level of lung function as measured by spirometry modifies CVD risk of SDB.
14. The impact of CVD risk factors differs with the presence or absence of SDB.
15. The impact of SDB on CVD risk is mediated by the effects of SDB on CVD risk factors, including blood glucose, insulin, and cholesterol levels, each of which may be increased via the effect of SDB on autonomic nervous system activity.
16. Self-reported sleep problems are associated with an increase in CVD events.

Last Updated:

12 Oct 2007