Effect of Antihypertensive Agents on Diastolic Function in Patients With Sleep Apnea
Condition: Hypertension; Sleep Apnea
MeSH terms: Apnea; Sleep Apnea Syndromes; Hypertension
Study type: Interventional
Phase: Phase 3

Summary: 
      The investigators investigated diastolic function among patients with obstructive sleep apnea
      (OSA) and hypertension stage I. In this randomized controlled trial, participants were
      randomly allocated to one of two groups: chlorthalidone associated with amiloride or
      amlodipine. Randomization was carried out prior to the start of the trial by an
      epidemiologist out of clinic and the randomization list was stratified by gender and severity
      of OSA. The research team and participants were blinded to the randomization list and
      allocation concealment was implemented. This trial aimed to detect changes in the
      echocardiography parameters with the drug treatment (higher in the intervention than in the
      placebo group). The investigators also assess change in daytime sleepiness among participants
      who already have been diagnosed with OSA.
    

Detailed description: 
      This is a randomized controlled trial, with participants randomly allocated to one of two
      groups: chlorthalidone associated with amiloride or amlodipine. Capsules were identical
      presentation and the research team and participants were blinded to the allocation list. The
      randomization list was stratified by gender and severity of OSA (AHI: 10-25 or 26-40) and in
      blocks in time, with size four and six units. Randomization was carried out prior to the
      start of the trial and it was generated by a validated software (Random Allocator). In order
      to ensure the confidentiality of the allocation list, it was generated by an epidemiologist
      who did not maintain direct contact with participants and the identification of the study
      drugs was done through alphanumeric code, implemented via software (RedCap).

      Adherence to treatment was measured by counting returned capsules and through the Morisky
      questionnaire with eight questions, validated for Portuguese. Participants underwent initial
      clinical evaluation prior to randomization and after eight weeks of treatment for evaluation
      of outcomes. Demographic characteristics (age, gender, skin color), socioeconomic level
      (education), previous morbidity (diabetes mellitus, stroke, acute myocardial infarction,
      cancer, rheumatic diseases), treatments in use (anti-diabetic, anti-depressants,
      non-steroidal anti-inflammatory, corticosteroids, nasal vasoconstrictor, appetite
      suppressants, lipid-lowering drugs) and lifestyle characteristics (smoking and drinking) were
      collected in a standardized way. The investigators also assess anthropometric measures such
      as weight, height, waist, neck and hip circumference, and bioimpedance for determination of
      lean and fat mass. Blood pressure was measured using a validated digital oscillometric
      monitor, with cuff appropriate to the arm circumference, and two measurements per visit were
      made. In addition, ECG was performed and biochemical parameters (creatinine, blood glucose,
      serum potassium, uric acid, cholesterol and fractions, C-reactive protein and NT-proBNP) were
      determined in the laboratory of Hospital de Clinicas de Porto Alegre.

      The transthoracic echocardiography is performed by the CX-50 unit (Philips, Bothell, WA -
      USA) with sectoral S5-1 transducer. Ambulatory monitoring of blood pressure will be measured
      through the Mortara AMBULO 2400 device (Mortara, Milwaukee, WI, USA) with measures 15/15
      minutes during the day and 20/20 minutes at night, within 24 hours of a working day.
      Polysomnography will be held in type III (home with device that measures at least 4
      cardiorespiratory variables) held with handset Sonmocheck (Weinmann GmbH, Hamburg, Germany),
      a monitor that detects the position of the patient, the presence of apneas or hypopneas,
      heart rate and digital oximetry.
    

Intervention name(s): Chlorthalidone plus amiloride; Amlodipine
Intervention type(s): Drug; Drug
Intervention description(s): A capsule with chlorthalidone plus amiloride was taken once daily in the morning for eight weeks.; A capsule of amlodipine was taken once daily in the morning for eight weeks.
Other intervention name(s): Chlo+Ami; Amlo
Intervention MeSH terms: Amlodipine; Chlorthalidone; Amiloride
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Sleep Apnea; Hypertension; Chlortalidone; Diastolic function