Relation between nocturnal decline in blood pressure and choroidal thickness: a comparative analysis in dipper vs. non-dipper hypertensive patients.

Abstract

To compare choroidal thickness (ChT) and echocardiographical changes in patients with dipper and non-dipper systemic arterial hypertension (HT). Patients with HT were evaluated in two groups according to the 24-hour ambulatory BP monitoring. Compared to day-time values, those whose night-time SBP decreased ≥10% were defined as dippers, and those whose SBP decreased <10% were defined as non-dippers. Transthoracic echocardiography was conducted in all patients. ChT and central macular thickness were measured with spectral-domain optical coherence tomography. ChT was obtained at the subfoveal, 1500 µm nasal and temporal to the fovea. Thirty non-dipper (18 females and 12 males) and 23 dipper (16 females and seven males) hypertensive patients were recruited. Sex distribution and the mean age were similar between the groups (P = 0.472; P = 0.12). Disease duration was longer in the non-dipper group (8 ± 3.39 vs. 4.96 ± 1.19 years, P = 0.001). The non-dipper group had lower ChT in subfoveal and temporal locations (P = 0.02 and 0.03, respectively) and higher left atrial volume index (LAVI) and pulmonary valve maximum flow (PV-max; P < 0.001). The night-time SBP was negatively correlated with ChT (P = 0.048) and positive correlated with LAVI and PV-max (P < 0.05). However those correlations were not significant when were controlled by the possible confounding factors as disease duration, age and gender. Non-dipper HT patients may have thinner choroid than dippers due to longer duration of HT and higher ambulatory BP levels.