[OP.LB01.07] a Comparison of the Impact of Morning or Night Delivery of Antihypertensive Agents on 24 Hour Ambulatory Blood Pressure Monitoring (Abpm) Levels

Abstract

Some data suggest that nocturnal rather than daytime dosing of antihypertensive agents may have beneficial effects on consequent cardiovascular outcomes. This trial was designed to evaluate whether ABPM levels differ by timing of drug dosing as a possible explanation for these observations. Design & Method 103 male or female patients aged 18-80 years with "controlled" hypertension (≤150/≤90 mmHg) for at least 3 months on stable therapy of ≥1 antihypertensive agent, were recruited from 1 of 2 centres in London & Thessaloniki. Patients were randomised to receive their usual therapy either in the morning (6am -11am) or the evening (6pm-11pm) for 12 weeks then participants crossed-over to the alternative timing of drug administration for a further 12 weeks. Clinic BPs using standardised methodology and a 24 hour ABPM recording were taken at baseline 12 and 24 weeks as were routine blood tests and completion of the EQ-5D-5L questionnaire for quality of life. With 90 recruits completing the trial the study had 80% power (α = 0.05 ) to detect a 3mmHg difference in mean 24h SBP. Regression modelling was used to calculate confidence intervals adjusted by centre, period (visit), sequence (group). Results 95 patients (92%) completed all 3 ABPM recordings.