Abstract 16013: The Dominant Role of the Systolic over the Diastolic Component of Blood Pressure Non-dipping as a Determinant of Target Organ Damage in Never Treated Hypertension. Implications in Dipping Definition
Introduction: Blood pressure (BP) non- dipping has been associated with target organ damage (TOD) and adverse outcomes in hypertension. Diverse definitions of non- dipping appear in the literature regarding the BP components taken into account.
Hypothesis: Isolated systolic compared to diastolic and to combined systolic and diastolic non- dipping is accompanied by increased markers of TOD and represents a more powerful predictor of TOD in never treated hypertensives.
Methods: 475 subjects with never treated essential hypertension stage I, II were divided according to a nocturnal BP reduction of <10% in their ambulatory BP recordings, in isolated systolic non- dippers (SND, n=76) isolated diastolic non- dippers (DND, n= 64) and combined systolic — diastolic non- dippers (SDND, n=136). All participants were subjected to echocardiographic examination, carotid to femoral pulse wave velocity (c-f PWV) and albumin to creatinine ratio (ACR) determination. Metabolic profile was determined in a morning blood sample.
Results: SND as compared to DND and SDND were of similar age, body mass index, waist circumference and metabolic profile (p=NS for all cases). In comparison with DND they had higher 24h systolic and pulse pressure (136±12 vs 128±11 and 52±6 vs 46±7 mmHg, p<0.05). SND compared to DND and SDND also exhibited higher left ventricular mass index (LVMI) (42.4±9.9 vs 38.0±9.1 vs 40.9±11.0 g/m2.7, p<0.05), higher log10(c-f PWV) (0.94±0.07 vs 0.86±0.05 vs 0.91±0.07 m/s, p<0.005) and higher log10(ACR) (1.2±0.5 vs 0.9±0.3 vs1.1±0.4 mg/g, p<0.05). In multiple regression analyses systolic BP non- dipping was an independent determinant, of all three studied indices of target organ damage (TOD) while diastolic BP non- dipping was not.
Conclusions: Isolated systolic BP non- dippers exhibit higher LVMI, c-f PWV and ACR in comparison with isolated diastolic and combined systolic- diastolic BP non- dippers. Moreover systolic non- dipping was related as an independent prognosticator with the above indices of TOD while diastolic non- dipping was not. In conclusion isolated systolic BP non- dipping may provide sufficient prognostic data, as regards the above surrogates of cardiovascular risk.
- © 2010 by American Heart Association, Inc.