Adults with obstructive sleep apnea (OSA) who experience excessive sleepiness while awake appear to be at far greater risk for cardiovascular diseases than those without excessive daytime sleepiness, according to new research published online in the American Thoracic Society's American Journal of Respiratory and Critical Care Medicine.
The current study analyzed data from 1,207 adults participating in the Sleep Heart Health Study, available from the National Sleep Research Resource. Patients were 40 years old or older at enrollment and were followed for nearly 12 years. The patients had moderate to severe OSA, which was defined as having at least 15 episodes per hour while sleeping when they stopped breathing (apnea) or had reduced breathing (hypopnea). The metric is known as the apnea-hypopnea index, or AHI.
Given the observational study design, they could not prove that excessively sleepy subtype was a causal factor for cardiovascular disease. Ultimately, excessive sleepiness could be a "surrogate marker of underlying cardiovascular risk pathways," they wrote.
However, the authors demonstrate that the association is independent of a number of demographic and health factors that might have biased results, including age, body mass index , smoking, diabetes, hypertension, cholesterol and medications.