Complex Exercise Intervention to Normalize Blood Pressure and Nocturnal Dipping in Patients With Hypertension

Effectiveness of a Complex Exercise Intervention to Normalize Blood Pressure and Its Nocturnal Dipping in Patients With HyperTension in Primary Care: a Randomized-controlled Trial

Background: Non-dipping hypertension(HT) (as defined by lack of decrease in systolic blood pressure (BP) by 10% during sleep) predicts cardiovascular events and mortality; however, there is a lack of evidence based treatment for non-dipping HT. While exercise is recommended to management HT, its effect on dipping status is not known. There is a lack of trials describing the relationship of exercise and blood pressure in Chinese.

Method: This will be a two-arm randomized controlled trial in which Chinese non-dippers (n= 198) will be randomized to an exercise program plus usual care or to usual care by stratified randomization. The randomization sequence is blinded to the investigators and allocation is disclosed only after valid consent. The exercise program utilizes various motivational techniques to enhance exercise maintenance.

Inclusion Criteria:

• SBP non-dippers
• self-reported exercise intensity and duration less than the World Health Organization recommendation, which is exercise of moderate intensity less than 150minutes/week OR exercise of vigorous intensity of less than 75 minutes/week
• Used any mobile apps on their phone (because the intervention involve use of apps to monitor and remind regular exercise)

Exclusion Criteria

• Patients with diagnosed chronic obstructive lung disease and recent stroke (within last 12 months) because other evidence-proven and well-structured programmes are implemented for these patients in the hospital authority in Hong Kong

• Occupational drivers - because they need to hold their arm still during ABPM and this may be hazardous for drivers

  • night-time workers
  • diagnosed Obstructive Sleep Apnea

• Patients on anti-coagulants - because ABPM may induce bruises

• Patients on 3 or more medications for hypertension (on maximum tolerable doses) - these patients may have secondary HT and represent a different spectrum of organic diseases

• Patients with SBP >180mmHg or DBP >110mmHg - drug titration is not allowed during the 12-week program and these patients need early drug treatment

• Patient with DM - these patients will be arranged to have another EIM program especially designed for their DM.

  • Patients with active spinal cord compression or spinal radiculopathy because they may not be suitable to join some exercise
  • patients with atrial fibrillation are excluded because these patients have increased BP variability and may have different dipping behaviour
  • patients with metallic implants or pacemakers are excluded as they are not suitable for MRI

• To maximize safety of patients, patients who are relatively contraindicated according to AHA will also be excluded

  • acute myocardial infarction in last 6 months
  • ongoing angina
  • uncontrolled cardiac arrhythmia
  • acute diseases including known active endocarditis/acute pulmonary embolism, pulmonary infarction, deep vein thrombosis, acute aortic dissection, acute myocarditis
  • known aortic stenosis
  • known heart failure
  • known obstructive left main coronary artery stenosis
  • uncontrolled ventricular rates
  • complete heart block
  • known hypertrophic obstructive cardiomyopathy
  • mental impairment that limit co-operation
  • resting blood pressure with systolic blood pressure >180mmHg or diastolic blood pressure >110mmHg
  • known anemia with hemoglobin level less than 11gm/dL
  • known uncorrected electrolyte imbalance, and
  • known uncontrolled hyperthyroidism.