LEFT VENTRICULAR MASS ASSESSMENT IN NOCTURNAL HYPERTENSION.

S. PEREZ-LLORET; J.E. TOBLLI; D.P. CARDINALI; J. MILEI

Madrir

Congreso; Congreso de la Sociedad Europea de Hipertension; 2006

BACKGROUND: Systolic and diastolic blood pressure (SBP and DBP) show 24-h rhythms with a nocturnal fall. Absence of the nocturnal fall is associated with higher cardiovascular morbidity and mortality. OBJECTIVE: To assess the left ventricular mass in diurnal and nocturnal hypertensive subjects. METHODS: Echocardiography and 24-h Ambulatory Monitoring of BP (Oxford Medilog) were performed in 291 subjects. Left ventricular mass index (LVMI) was calculated by the Devereux method. Diurnal and nocturnal hypertension (HT-D and HT-N, respectively) were defined as diurnal SBP/DBP > 135/85 mmHg and nocturnal SBP/DBP > 125/75 mmHg respectively (JNC7). Subjects with nighttime SBP fall < 10% were considered non-dippers. Results were analyzed by two-way ANOVA and multivariate regression analyses. RESULTS: One-hundred twelve subjects (31%) were HT-D; 31% were also HT-N. On the contrary, only 5% out of the 179 normotensive subjects were HT-N. One-hundred subjects were on antihypertensive treatment, of whom 43% were HT-D and 17% HT-N. Non-dippers hypertensives showed increased LVMI as compared with the dipper ones (135±5 g/m2 vs 117±4 g/m2 respectively, p<.04). No such difference could be found between dipper and non-dipper normotensive subjects. On the contrary, when the ANOVA model included HT-D and HT-N, HT-N subjects showed greater LVMI as compared to nocturnal normotensives (131±3 g/m2 vs 115±8 g/m2 respectively, p=0.04), independently of the occurrence of diurnal hypertension. A multivariate regression analysis showed that only nighttime SBP, age and gender were independently associated with LVMI, whereas diurnal BP means and nocturnal dipping were not. CONCLUSION: Nighttime hypertension is probably a stronger risk factor for cardiovascular than diurnal hypertension. To evaluate end-organ damage the assessment of nocturnal hypertension by means of a fixed cut-off limit (125/75 mmHg) may prove to be more useful than the assessment of the nighttime BP fall magnitude.