Effect of bedtime administration of blood-pressure lowering agents on ambulatory blood pressure monitoring results: A meta-analysis

BACKGROUND: Bedtime administration of antihypertensive drugs currently receives more at-tention, but no clear consensus has been reached on the blood pressure (BP)-lowering effect of this strategy. METHODS: We systematically searched literature for clinical trials of ingestion time of anti-hypertensive drugs evaluated by ambulatory blood pressure monitoring (ABPM) to perform a meta-analysis which aimed at determining the difference in diurnal, nocturnal, and 24-h mean of systolic BP (SBP) and diastolic BP (DBP), absolute BP reduction from baseline between bedtime administration group (experimental group) and morning (awaking) administration group (control group). RESULTS: The synthesis analysis showed that the level of BP in bedtime administration group was lower than the morning administration group, which reduced diurnal SBP/DBP by 1.67/1.13 mm Hg (p = 0.36/0.48), 24-h SBP/DBP by 2.78/0.36 mm Hg (p = 0.09/0.62), nocturnal SBP/DBP by 6.32/3.17 mm Hg (p = 0.03/0.007). Furthermore, there was lack of statistically significant differences in the diurnal mean of SBP/DBP reduction from baseline between the two groups (p = 0.94/0.85), but bedtime administration resulted in significant reduction from baseline in the nocturnal mean of SBP/DBP, by -4.72/-3.57 mm Hg (p = 0.01/0.05). Funnel plot demonstrated that there was no evidence of publication bias. CONCLUSIONS: Administration of ≥ 1 antihypertensive drugs at bedtime or evening results in a greater reduction of nocturnal hypertension than dosing in the morning without loss of efficacy of diurnal and 24 h mean BP reduction.