AMBULATORY BLOOD PRESSURE VARIABILITY IN NORMOTENSION AND IN WHITE COAT, MASKED AND SUSTAINED HYPERTENSION. DATA FROM THE SPANISH AMBULATORY BLOOD PRESSURE REGISTRY: PP.3.100

Abstract

Objective: Based on their office and ambulatory blood pressure (BP), subjects can be classified as normotensive (NT), white coat, masked or sustained hypertensive (WCHT, MHT, SHT, respectively). It is not clear whether these categories are associated with differences in the degree of daily life BP variability (V). Aim of the present study was to assess this issue in a large group of subjects from the Spanish Ambulatory Blood Pressure Monitoring Registry. Methods: We analyzed ambulatory BP recordings (Spacelabs 90207) obtained in 18395 subjects (age: 52.8 ± 14.7 years, 55% males) not on antihypertensive medication for at least 2 weeks. Based on the accepted cutoffs for office (<140/90mmHg) and 24 h (<130/80mmHg) BP normality, subjects were classified as NT, WCHT, MHT and SHT. BPV was quantified as 24 h standard deviation (SD), weighted 24 h (wSD) and average real variability (ARV: average absolute BP difference between successive readings) for systolic (S) and diastolic (D)BP. The difference in BPV between BP categories was assessed by an ANCOVA model adjusted for age, BMI, gender, smoking, diabetes, dyslipidemia, previous cardiovascular diseases, renal insufficiency and average 24 h SBP or DBP as appropriate. Results: The distribution of subjects was as follows: 15.8%, 30.0%, 6.4% and 47.8% in NT, WCHT, MHT and SHT groups, respectively. The adjusted estimates of 24 h SBPV and DBPV in the four groups are shown in Table. Compared to NT, night-time SBP SD was similarly elevated in MHT and SHT (p < 0.001), but not in WCHT.Conclusions: Compared to NT, after adjusting for mean BP we found an increased 24 h BPV in WCHT similar to that observed in SHT, with smaller differences in MHT. Conversely, night-time BPV was increased in MHT and in SHT but not in WCHT. Our data suggest that increased office BP is associated with higher BP reactivity to daily life stimuli, irrespective of differences in average out-of-office BP. These findings may be relevant when considering the higher cardiovascular risk reported by some studies in WCHT.