PT - JOURNAL ARTICLE AU - Nashwa AbdelWahab AU - Yassmin AlAshram AU - Iman Diab TI - Pattern of nocturnal blood pressure in obstructive sleep apnea syndrome, relation of oxidative stress and endothelin-1 precursor to hypertension DP - 2012 Sep 01 TA - European Respiratory Journal PG - P3869 VI - 40 IP - Suppl 56 4099 - http://erj.ersjournals.com/content/40/Suppl_56/P3869.short 4100 - http://erj.ersjournals.com/content/40/Suppl_56/P3869.full SO - Eur Respir J2012 Sep 01; 40 AB - Background: Large epidemiologic studies have established that OSA is a risk factor for developing hypertension.Objective: To examine the pattern of nocturnal blood pressure in patients with OSA and its relation to polysomnographic findings and studying the relation of serum malondialdehyde (MDA) as a marker of oxidative stress and big endothelin -1 to hypertension in OSA.Subjects and Methods: Thirty eight patients with OSA and ten normal control subjects were subjected to early morning blood samplings for measurement of serum MDA and big endothelin – 1. All patients with OSA were subjected to full polysomnographic study and monitoring of nocturnal blood pressure (BP) changes.Results: Absence of normal nocturnal dipping in blood pressure (BP) was the most prominent feature in patients with OSA in association with repetitive increase in BP during sleep. The level of dipping in BP was correlated inversely with arousal index while Index of increase in BP was correlated directly with both AHI and oxygen desaturation index. Both serum MDA and big endothelin -1 were significantly higher in patients with OSA than control subjects.Conclusions: OSA should be considered as part of the workup of patients with hypertension especially in those whose 24 hour BP studies yielded blunted nocturnal dipping. Repetitive episodes of upper airway occlusion give rise to acute stressors such as hypoxemia, reoxygenation, oxidative stress and arousals. Another factor related to endothelial dysfunction is increased endothelin precursor concentration. There may be differential effects related to each stressor, and these effects may be cumulative over time.