Obstructive Sleep Apnea (OSA) is a complex disease process with a known significant association with cardiovascular diseases and the metabolic syndrome. This study aimed to define phenotypes of OSA based on sleep studies and cardiovascular comorbidities and to further investigate whether there would be any meaningful association between these disease processes. Defining phenotypes could assist in individual targeted treatments for patients with OSA.
We conducted a retrospective chart review on sleep studies between 12/6/2015 and 5/18/17 and identified 1056 adult patients. We documented all aspects of the sleep studies and then did a chart review on the identified patients in our Electronic Medical Record (EMR) to study cardiovascular disease processes of hypertension, atrial fibrillation, coronary artery bypass surgery, severity of diabetes and the presence of prior stroke.
After comparing all our data, we found that lowest saturation, baseline saturation, N1, BMI, and N3 had strong correlations with AHI. Presence of diabetes and ESS number had no correlation. Hypertension and age had moderate while Rapid Eye Movement (REM) cycle, ECG abnormalities and sleep efficiency had small correlation with Apnea-Hypopnea Index (AHI).
Only hypertension had a significant effect on the clustering. The rest of the majority of the clusters were formed by differences in sleep stages, Respiratory Disturbance Index (RDI), lowest saturation points and sleep efficiencies. Based on these results, our study did not show a significant association between the cardiac comorbidities and sleep study outcomes as clustering.