Using Night-time Blood Pressure to Treat Hypertension

Study Overview
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Brief Summary
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Objectives: To examine the feasibility of conducting night-time home blood pressure(BP) monitoring (during sleep) and titration of medications in the evening. This will provide data for sample size calculation for the main trial, which will examine whether night-time BP is a better target than conventional daytime BP for hypertension management. Hypothesis to be tested: night-time home BP monitoring(HBPM) and evening drug titration are acceptable to patients; and future main trial is feasible in terms of recruitment/dropout rate/medication adherence. Design and subjects: This pilot randomized-controlled trial will recruit 78 patients with nocturnal hypertension (asleep systolic BP 120mmHg on ambulatory blood pressure monitoring(ABPM)). They will be allocated in 1:1 ratio to have their medication titrated in the evening according to night HBPM (Experimental group) or in the morning according to daytime HBPM (control group) respectively. Instruments: ABPM/HBPM. Interventions: titration of the dose(s) of anti-hypertensive medications in the evening according to night HBPM (experimental group) and in the morning according to daytime HBPM (control group) every 4 weeks. Main outcome measures: ABPM at baseline and at 6 months Data analysis and expected results: The rate of recruitment/dropout and adherence to night HBPM will be presented. The feasibility of HBPM will be assessed by the patients' adherence to HBPM and by patients' interviews. ANCOVA will be used to evaluate whether titration of medication can normalize BP levels. We expect patients to have a high adherence rate and that titration of evening doses of medications will better improve night-time BP on ABPM.

Official Title
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Home Blood Pressure During Night-time Sleep as a Better Treatment Target for Patients With Hypertension: a Proof-of-concept Randomized Controlled Trial

Conditions
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Hypertension

Intervention / Treatment
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* Behavioral: treatment of BP by using night-time BP
* Behavioral: treatment of BP by using daytime BP


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: diagnosed hypertension (HT) from clinical records nocturnal HT (night-time systolic blood pressure (SBP) during sleep ≥120 mmHg) and stage I hypertension (daytime SBP = 135-159mmHg) Exclusion Criteria: patients with atrial fibrillation (many home blood pressure (BP) machines are not validated in these patients and these patients have greater BP variability) daytime office systolic BP ≥180 mmHg or diastolic BP ≥120 mmHg (regardless of nocturnal BP) because these patients need urgent BP treatment and it is not known if medications given in the evening are equally effective patients with known obstructive sleep apnoea because the night-time BP of these patients is predominately affected by the sleep apnoea patients with known stroke, ischemic heart disease, heart failure, kidney failure, peripheral vascular disease and diabetes mellitus because their daytime BP targets will be different dementia or psychiatric illness that impairs patients' ability to perform home blood pressure monitoring (HBPM) by themselves patients with end-stage malignancies nocturnal worker, because they will have a reverse BP pattern to other participants patients who sleep after 2am or wake up before 4am because these patients will not be asleep during night HBPM patients receiving ≥3 BP medications at maximal tolerated doses because there is little space for drug titration and these patients may have secondary HT representing another disease spectrum patients receiving anti-coagulants because ABPM can induce significant bruises (during repeated cuff inflations) in these patients.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: treatment by night-time BP<br>titrate drug treatment in the evening against night home blood pressure monitoring (HBPM) SBP (aiming SBP of <120 mmHg; intervention group) | Behavioral: treatment of BP by using night-time BP<br>* titration of BP medications to target according to night-time SBP<br>|
| Other: treatment by daytime BP<br>Usual care - titrate drug treatment in the morning against HBPM SBP (aiming SBP of <135 mmHg; control group) | Behavioral: treatment of BP by using daytime BP<br>* titration of BP medications to target according to daytime SBP<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| the rate of recruitment | number of participants recruited per month during recruitment period | 0 month to 18 month (anticipated recruitment period) | 
| feasibility of home blood pressure (BP) measurement | the proportion of patients who can measure nocturnal BP successfully | 0 month to 24 month (end of trial) | 
| feasibility of repeated ambulatory blood pressure monitoring (ABPM) | the proportion of patients finished both ABPM | 0 month to 24 month (end of trial) | 
| dropout rate | number of participants drop-out from each arm | 0 month to 24 month (end of trial) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| systolic BP (SBP) / diastolic BP (DBP) on ABPM | Mean daytime/night-time/24-hour SBP/DBP | taken at 0 month and 6 month for each patient | 
| serum creatinine level | an assessment for renal function (the higher value suggest poorer renal function) | taken at 0 month and 6 month | 
| lipid profile | low-density lipoprotein (LDL), high-density lipoprotein (HDL), Triglyceride (TG), total cholesterol (TC) | taken at 0 month and 6 month | 
| microalbuminuria | the presence of microalbuminuria suggest renal damage | taken at 0 month and 6 month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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hypertension, ABPM, nocturnal hypertension