Oxidative stress and baroreflex sensitivity in healthy subjects and patients with mild-to-moderate hypertension

Decreased baroreflex sensitivity (BRS) is a prognostic marker in essential hypertension. Animal experiments suggest that decreased BRS is related to increased oxidative stress. Our study was aimed at testing whether oxidative stress, estimated by isoprostane 15-F2t-IsoP urinary levels, is correlated to BRS variation in healthy subjects as well as in patients suffering from essential hypertension. Urinary 15-F2t-IsoP levels and BRS were evaluated in two groups of subjects: healthy volunteers (n=64) and patients with untreated mild-to-moderate hypertension (n=33). Data were analysed in 61 and 31 subjects, respectively, BRS analysis being impossible in three and two subjects, respectively. 15-F2t-IsoP levels were measured using gas chromatography/mass spectrometry. BRS was measured using the sequence method [PS+/RR+ and PS−/RR−] and crossspectral analysis (CSP) (MF gain) at rest, lying down. No significant correlation was found between basal urinary 15-F2t-IsoP levels and BRS (sequence method and CSP) in either healthy controls or hypertensive patients. Our study shows that oxidative stress is not involved in interindividual variations of BRS in healthy subjects and patients suffering from mild-to-moderate hypertension