The Dominant Role of the Systolic Component of Nondipping Status on Target-Organ Damage in Never-Treated Hypertensives

BACKGROUND: Blood pressure (BP) nondipping has been associated with target-organ damage (TOD) and adverse outcomes in hypertension. Diverse definitions of nondipping status appear in the literature, regarding the BP components taken into account. Aim of this study was to compare the effects of isolated nondipping of systolic, diastolic and combined systolic and diastolic BP on various indices of TOD. METHODS: From 630 consecutive subjects with never-treated essential hypertension stage I-II, we selected 279 subjects who were consistently isolated systolic nondippers (SND, n=76) isolated diastolic nondippers (DND, n=64) and combined systolic and diastolic nondippers (SDND, n=139) in two ambulatory BP monitoring sessions. All three subgroups were subjected to echocardiographic examination, carotid-femoral pulse wave velocity (PWV(c-f)) and albumin-to-creatinine ratio (ACR) determination. Metabolic profile was determined in a morning blood sample. RESULTS: SND compared to DND and SDND exhibited higher left ventricular mass/height(2.7) (42.4 ± 9.9 vs. 38.0 ± 9.1 vs. 40.9 ± 11.0 g/m(2.7), P < 0.05), higher log(10)(PWV(c-f)) (0.94 ± 0.07 vs. 0.86 ± 0.05 vs. 0.91 ± 0.07 m/s, P < 0.005), and higher log(10)(ACR) (1.2 ± 0.5 vs. 0.9 ± 0.3 vs. 1.1 ± 0.4 mg/g, P < 0.05). Isolated systolic BP nondipping was an independent determinant of all the studied indices of TOD whereas isolated diastolic BP nondipping was not. CONCLUSIONS: Isolated systolic as compared to diastolic and to combined systolic/diastolic BP nondipping is associated with higher left ventricular mass, stiffer arteries, and pronounced urinary albumin excretion.