Molecular Interactions between Gasotransmitters in Patients with Obstructive Sleep Apnea

Patients with obstructive sleep apnea (OSA) have an increased risk of cardiovascular disease (CVD). Nitric oxide (NO) and heme oxygenase-1 (HO-1) affect vascular tone and are vasoprotective. Furthermore, hydrogen sulfide (H2S), an HO-1 inducer, is known to be a major effector molecule driving apneas. This study was conducted to examine the molecular relationships between these gasotransmitters and HO-1 in patients with OSA. Individuals who presented for evaluation for possible OSA were recruited and underwent overnight polysomnography. Individuals with an apnea-hypopnea index (AHI) of >5 per hour (OSA diagnosis) were considered cases (n = 19), while those with an AHI of 0.5 μM were excluded. Interestingly, analysis of HO-1 did not show a significant change from baseline, confirming the inverse relationship between the two gasotransmitters. The alterations in the bioavailability of endogenous H2S and its molecular interactions with NO and HO-1 regulating vascular tone may play a role in the pathogenesis of CVD in OSA patients.