Association between asleep blood pressure and brain natriuretic peptide during antihypertensive treatment: The Japan Morning Surge-Target Organ Protection (J-TOP) study

Background: Asleep blood pressure (BP) has been shown to better reflect cardiovascular risk than awake BP in hypertensive patients. This study investigated the correlation of brain natriuretic peptide (BNP) to asleep BP during antihypertensive treatment. Methods: In the Japan Morning Surge-Target Organ Protection (J-TOP) study, which was an open-label multicenter trial to compare bedtime or awakening dosing of candesartan (+ diuretics as needed) among individuals with home SBP higher than 135 mmHg, we evaluated 254 hypertensive patients who underwent ambulatory BP monitoring, and measured their BNP at baseline and after 6th month of treatment. Results: At follow-up, the decrease in log-transformed BNP was significantly related to the decrease in asleep SBP (r = 0.27, P < 0.001); the relationship remained significant (β = 0.20, P = 0.002) even after adjusting for the decrease in the awake SBP (β = 0.001, P = 0.991). When we divided participants by their time of candesartan administration, the relationship between the decrease in log-transformed BNP and asleep SBP was still significant in both the awakening-dosing group (β = 0.21, P = 0.028) and the bedtime-dosing group (β = 0.21, P = 0.029). Furthermore, this relationship was strong in the participants who were receiving diuretics. Conclusion: The decrease in BNP is associated with asleep BP reduction by candesartan (+ diuretics as needed) over and above the awake BP reduction, regardless of the time of administration.