Effect of Hypertension on Left Ventricular Diastolic Dysfunction Associated with Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) and hypertension are known cardiovascular risk factors, but the effect of hypertension on OSA-related left ventricular diastolic dysfunction remains unclear.

This cross-sectional study enrolled 289 patients from the Second Affiliated Hospital of Fujian Medical University (January 2013-January 2023). Participants were classified as healthy controls (HC), OSA-only (OSA), hypertension only (HTN), and OSA with hypertension (OSA-HTN). Furthermore, based on the AHI (Apnea-Hypopnea Index) values, the OSA group and the OSA-HTN group were further divided into three subgroups: mild (5≤AHI<15 events/hour), moderate (15≤AHI<30 events/hour), and (AHI≥30 events/hour). Participants underwent biochemical testing, echocardiography, and polysomnography. Echocardiographic parameters of diastolic function-interventricular septum thickness (IVST), left ventricular posterior wall thickness (LVPW), left atrial volume index (LAVI), E/A ratio, and E/e' ratio-were compared among the groups. One-way analysis of variance and statistical interaction analysis evaluated the independent and interactive effects of hypertension and OSA severity on E/e'.

Compared with the HC group, the HTN, OSA, and OSA-HTN groups showed significantly higher IVST, LVPW, LAVI, and E/e' ratio (p<0.05), with the OSA-HTN group exhibiting the greatest impairment. The E/e' ratio increased with OSA severity and correlated positively with systolic blood pressure and diastolic blood pressure, most strongly in the OSA-HTN group. Hypertension (mean difference=-1.784, 95% CI: -2.868 to -0.701, p=0.001) and OSA severity independently affected E/e' with a significant multiplicative interaction (p<0.05).

Both hypertension and severe obstructive sleep apnea are independently associated with impaired left ventricular diastolic function, and their coexistence may have a potential synergistic effect.