Is there any true distinction in extreme dipping versus nondipping or dipping phenotype regarding hypertension-mediated organ damage in newly diagnosed and never-treated hypertensive patients?

Abstract

Dipping phenomena is defined as nocturnal BP fall >10% during 24-h ambulatory blood pressure (BP) monitoring (ABPM) which carries a favorable cardiovascular risk (CVR) prognosis due to reduced 24-h hypertension burden. To date, extreme dipping phenotype (defined as BP decrease ≥20%) has led to controversial prognostic results regarding CVR. We aimed to explore hypertension-mediated organ damage (HMOD) in extreme dippers compared to the other dipping phenotypes (nondipping, dipping). From 490 consecutive patients with newly diagnosed never-treated arterial hypertension (mean age 51 ± 11 years, 294 males) subjected to 24-h ABPM, we studied 52 extreme dippers, 52 age- and gender-matched nondippers, and 52 age- and gender-matched dippers. All patients were subjected to arterial stiffness (PWV), 24-h microalbumin levels, carotid intima-media thickness (cIMT), diastolic dysfunction (E/Ea), and left ventricular mass index (LVMI) evaluation. ANOVA analysis found no differences regarding HMOD between groups. Multiple regression analysis revealed the following independent direct relationships between: (i) office SBP and PWV in nondippers (β = 0.35, p = 0.01) and extreme dippers (β = 0.49, p < 0.001), (ii) office SBP and E/Ea in extreme dippers (β = 0.39, p = 0.007), (iii) 24-h diurnal and nocturnal SBP and E/Ea in dippers (β = 0.40, p = 0.004, β = 0.39, p = 0.005, and β = 0.40, p = 0.004, respectively), and (iv) 24-h and nocturnal SBP and LVMI in nondippers (β = 0.29, p = 0.04 and β = 0.36, p = 0.009, respectively). In the early phases of untreated-arterial hypertension disease, extreme dipping phenotype in middle-aged hypertensives does not imply an adverse or favorable prognosis regarding the incidence of HMOD either as continuous variables or as abnormal HMOD compared to other dipping phenotypes.