Masked hypertension in obstructive sleep apnea syndrome.
BACKGROUND
Ambulatory blood pressure (BP) monitoring (ABPM) detects subjects with normal clinic but high ambulatory 24-h BP, that is, masked hypertension.


METHODS
One hundred and thirty newly diagnosed obstructive sleep apnea syndrome (OSAS) patients, free of recognized cardiovascular disease were included (111 men, age = 48 +/- 1 years, BMI = 27.6 +/- 0.4 kg/m, respiratory disturbance index (RDI = 42 +/- 2/h). Clinic BP, 24-h ABPM, baroreflex sensitivity (BRS), echocardiography and carotid intima-media thickness (IMT) were assessed.


RESULTS
Forty-one patients (31.5%) were normotensive, 39 (30.0%) exhibited masked hypertension, four (3.1%) white-coat hypertension and 46 (35.4%) hypertension. Significant differences were found between normotensive, masked hypertensive and hypertensive patients in terms of BRS (10.5 +/- 0.8, 8.0 +/- 0.6 and 7.4 +/- 0.4 ms/mmHg, respectively, P < 0.001), carotid IMT (624 +/- 17, 650 +/- 20 and 705 +/- 23 microm, respectively, P = 0.04) and left ventricular mass index (37 +/- 1, 40 +/- 2 and 43 +/- 1 g/height2.7, respectively, P = 0.003). A clinic systolic BP more than 125 and a diastolic BP more than 83 mmHg led to a relative risk (RR) of 2.7 and a 90% positive predictive value for having masked hypertension.


CONCLUSIONS
Masked hypertension is frequently underestimated in OSAS and is nearly always present when clinic BP is above 125/83 mmHg.
Baguet
Jean-Philippe
JP
Clinic of Cardiology, University Hospital, France. JPBaguet@chu-grenoble.fr
Lévy
Patrick
P
Barone-Rochette
Gilles
G
Tamisier
Renaud
R
Pierre
Hélène
H
Peeters
Marie
M
Mallion
Jean-Michel
JM
Pépin
Jean-Louis
JL
D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000473:pathology; D015331:Cohort Studies; D003324:Coronary Artery Disease / Q000150:complications; D004452:Echocardiography; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications* / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000150:complications*; D017539:Tunica Intima / Q000473:pathology; D017540:Tunica Media / Q000473:pathology