Overview
This prospective, parallel-group randomised controlled trial evaluates whether cognitive-behavioural therapy for insomnia (CBT-I) improves arterial function and psychological and cognitive outcomes in hypertensive patients with poor sleep quality. Adults aged 18-70 with controlled hypertension and poor baseline sleep quality (sleep efficiency \<=85%) are randomised 1:1 to CBT-I (four weekly 60-minute sessions) or passive sleep education. The primary outcomes are change from baseline in pulse wave velocity and central arterial pressure at 12 months. Secondary outcomes include blood pressure, depressive symptoms, perceived stress, cognitive complaints, and sleep quality, assessed at baseline, 1, 6, and 12 months.
Description
Background: Poor sleep quality is associated with increased arterial stiffness, depression, and cognitive decline, all of which contribute to cardiovascular risk in hypertensive patients. This trial tests whether improving sleep through CBT-I can attenuate arterial dysfunction and psychological/cognitive burden.
Design: Prospective, single-centre, parallel-group randomised controlled trial with 1:1 allocation, conducted at the Hypertension and Psychiatry Outpatient Clinics of the Unidade Local de Saude Alto Ave (ULSAAVE).
Intervention: CBT-I delivered in four weekly 60-minute sessions (sleep hygiene, stimulus control, relaxation techniques), adapted for participants with mild obstructive sleep apnea or comorbid insomnia and sleep apnea (COMISA).
Comparator: Passive sleep education (informational leaflets plus non-interactive follow-up calls); control participants are offered CBT-I after study completion.
Randomisation and blinding: Computer-generated block randomisation (blocks of 4-6), 1:1 allocation, with allocation concealment via sequentially numbered, opaque, sealed envelopes managed by a third party. Outcome assessors and data analysts are blinded; participants are partially blinded (control presented as an educational intervention).
Sample size: 234 participants (117 per group), accounting for 20% attrition, powered (80%, alpha 0.05) to detect a 0.4 m/s between-group difference in pulse wave velocity at 12 months.
Analysis: Linear mixed-effects models for repeated measures (time as fixed effect, participant as random effect, group as factor), with baseline apnea-hypopnea index included as a covariate.
Eligibility
Inclusion Criteria:
- Adults aged 18 to 70 years
- Controlled hypertension
- Poor baseline sleep quality (sleep efficiency \<=85% assessed via actigraphy or type II polysomnography)
- Capable of providing informed consent
- Participants with mild obstructive sleep apnea (apnea-hypopnea index 5-14.9/h on type II polysomnography) who do not meet criteria for CPAP/PAP therapy are eligible
Exclusion Criteria:
- Severe cardiovascular disease (e.g., acute myocardial infarction or stroke)
- Severe neurological diseases
- Moderate-to-severe obstructive sleep apnea (AHI \>=15/h) or any obstructive sleep apnea with an indication for CPAP/PAP therapy
- Central disorders of hypersomnolence
- Intellectual disability
- Pregnancy
