Abstract 5860: Among Subjects With Nocturnal Hypertension Dipping Sub-classification Carries No Additional Prognostic Importance
Introduction: Both nocturnal hypertension and non-dipping status have been associated with increased rates of target organ damage and adverse cardiovascular outcomes. Their relative prognostic importance in the risk stratification of hypertensives has not been elucidated.
Hypothesis: We assessed the hypothesis that among subjects with nocturnal hypertension dippers and non- dippers do not differ in terms of subclinical target organ damage
Methods: From a population of 278 consecutive untreated subjects with essential hypertension, we selected 167 nocturnal hypertensives on the basis of ambulatory BP monitoring, night- time BP≥120/70 mmHg. These subjects were subdivided into dippers (n=105) and non- dippers (n=62) according to a nocturnal BP reduction of =10% or ≥ 10% respectively. All subjects underwent echocardiographic examination and determination of pulse wave velocity (PWV) determination and urine albumin to creatinine ratio ACR).
Results: Non- dipper as compared to dipper nocturnal hypertensives were older by 4.4 years (p=0.001) while they did not differ regarding body mass index, waist to hip ratio and gender (p=NS for all cases). No differences between the two groups were observed regarding left ventricular mass index (LVMI) (89.2±21 vs 92.6±22 g/m2), tissue Doppler imaging derived indices of diastolic function Em (0.06±0.002 vs 0.07±0.003 m/s) and Em/Am (0.72±0.1 vs 0.75±0.2), PWV (8.26±1.2 vs 8.25±1.5 m/s) and ACR (27.3 vs 29.8 mg/g) (p=NS, in all cases). In nocturnal hypertensives nighttime systolic BP and male gender were prognosticators of LVMI(R2=0.37, p<0.0005), 24h PP, age and male gender were prognosticators of PWV (R2=0.24, p<0.0005), and 24h PP and PWV was the prognosticator of ACR (R2=0.18, p<0.0005). Nocturnal BP fall did not constitute an independent predictor for none of the above assessed indices of target organ damage.
Conclusion: Among subjects with nocturnal hypertension, dippers compared to non- dippers did not differ regarding LVMI, PWV and ACR. This finding implies a distinct prognostic role of nocturnal hypertension which abolishes the value of the dipping classification in the risk stratification of hypertensives at least in this setting.