Sleep apnoea and memory

ISRCTN	ISRCTN11309942
DOI	https://doi.org/10.1186/ISRCTN11309942
ClinicalTrials.gov (NCT)	Nil known
Clinical Trials Information System (CTIS)	Nil known
Integrated Research Application System (IRAS)	340207
Protocol serial number	NIHR207185
Sponsor	North Bristol NHS Trust
Funders	National Institute for Health and Care Research, Goldman Foundation

Submission date: 08/10/2025
Registration date: 11/11/2025
Last edited: 11/11/2025

Recruitment status: Recruiting
Overall study status: Ongoing
Condition category: Nervous System Diseases

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Record updated in last year

Plain English summary of protocol

Background and study aims
This study wants to find out how many people who have memory and thinking problems also have sleep apnoea. It will also look at what symptoms are related to having sleep apnoea in people with memory and thinking problems.

What is sleep apnoea?
Sleep apnoea is when your breathing stops and starts while you sleep. Pauses in breathing are called “apnoeas” and can last from a few seconds up to a minute. Too many apnoeas might affect how deep and restful your sleep is. Many people do not know they have sleep apnoea.

Who can participate?
People attending memory clinics at a participating site.

What does the study involve?
First, patients will be asked to complete a consent form to say they are happy to take part. Some information will be taken from medical records, and participants will be asked to complete some questionnaires (online if possible, but on paper or by telephone otherwise) about themselves and their sleep. Participants will be asked to wear a device called a WatchPAT for one night whilst sleeping at home. The device looks like a watch but also has a finger sleeve and a sticky pad that attaches to the chest. The WatchPAT will check for sleep apnoea. Participants and their GP will be informed of the results (whether they have sleep apnoea) and what the next steps are.

If referred for sleep apnoea treatment in the Bristol area, the study team may ask to take some blood samples before and after treatment to see if levels of certain proteins change after treatment for sleep apnoea.

Taking part is optional. Patients can also decide to take part and change their minds later. This decision won’t have an impact on their healthcare.

What are the possible benefits and risks of participating?
Participants may get a new diagnosis of sleep apnoea. Treating sleep apnoea may improve sleep quality, reduce the risk of other health conditions such as strokes, and help people feel better in the daytime. If someone has severe sleep apnoea or feels very sleepy in the day, they may be asked to stop driving or take a driving test to make sure they and others around them are safe.

This is an observational study which carries no significant risks. The main risks has already been listed (implications on insurance and driving).

Where is the study run from?
The memory clinic that the patient attends and from home. Several memory clinics across the country are taking part. The research is being led by North Bristol NHS Trust, UK.

When is the study starting and how long is it expected to run for?
The study is scheduled to start in late 2025 and recruit until August 2026 (or 10 months from opening). Most participants will only be involved in the study for a very short time, though participants referred for sleep apnoea treatment at the Bristol site may be involved for several months, with blood tests every 4-8 weeks.

Who is funding the study?
1. The National Institute for Health and Care Research (NIHR), UK.
2. Goldman Foundation.

Who is the main contact?
Study coordinator Victoria Gabb, victoria.gabb@bristol.ac.uk

Contact information

Ms Victoria Gabb
Public, Scientific

Victoria Gabb
ReMemBr Group Research Team
Bristol Brain Centre
Elgar House
Southmead Hospital
Bristol
BS10 5NB
United Kingdom

ORCID ID	0000-0002-7688-766X
Phone	0117 456 0700
Email	victoria.gabb@bristol.ac.uk

Prof Elizabeth Coulthard
Principal investigator

Dementia Research Team
Bristol Brain Centre
Elgar House
Southmead Hospital
Bristol
BS10 5NB
United Kingdom

ORCID ID	0000-0002-0017-9595
Phone	0117 414 7801
Email	elizabeth.coulthard@bristol.ac.uk

Study information

Primary study design	Observational
Study design	Multi-centre observational cross-sectional study with a longitudinal observational cohort sub-study at one site
Secondary study design	Cross sectional study
Study type	Participant information sheet
Scientific title	Sleep apnoea symptoms and prevalence in people attending memory services
Study acronym	SAM
Study objectives	The primary objective of this study is to determine prevalence of sleep apnoea in UK memory services, with an exploratory aim to determine whether sleep apnoea prevalence differs between different types of dementia diagnosis. Secondary objectives are to: determine clinical factors/symptoms that best predict sleep apnoea in people who present to memory clinics, determine the feasibility of remote questionnaires for sleep apnoea screening, and pilot methodology for observing the effect of treating sleep apnoea on blood biomarkers for Alzheimer’s disease and neurodegeneration.
Ethics approval(s)	Approved 05/09/2025, North West - Greater Manchester South Research Ethics Committee (3rd Floor, Barlow House 4 Minshull Street, Manchester, M1 3DZ, United Kingdom; +44 (0)207 104 8014; gmsouth.rec@hra.nhs.uk), ref: 25/NW/0221
Health condition(s) or problem(s) studied	Sleep apnoea in patients attending memory clinics
Intervention	Main study Participants will be asked to complete questionnaires to identify risk factors and symptoms relating to sleep apnoea and undergo a night of sleep apnoea screening using the WatchPAT polygraphy device. Data will also be collected from medical records. Participants will be informed of their results. Bloods sub-study Participants with sleep apnoea who are referred to treatment at the North Bristol site will be invited to undergo blood tests before and after treatment to assess whether blood biomarkers change following treatment for sleep apnoea. The study will also pilot a methodology for determining the change in serum biomarkers of Alzheimer’s disease and neurodegeneration after starting sleep apnoea treatment and report the change over time in biomarkers.
Intervention type	Not Specified
Primary outcome measure(s)	The proportion of people in memory clinics who have at least mild sleep apnoea (Oxygen Desaturation Index 3% > 5) according to a single night of overnight polygraphy (WatchPAT)
Key secondary outcome measure(s)	1. The proportion of people with different aetiological diagnoses in memory clinics who have at least mild sleep apnoea (Oxygen Desaturation Index (ODI)3% > 5) according to a single night of overnight polygraphy (WatchPAT). 2. The proportion of people in memory clinics who have mild (ODI 3% > 5-15), moderate (ODI 3% > 15-30) or severe (ODI 3% > >30) sleep apnoea according to a single night of overnight polygraphy (WatchPAT). 3. Proportion of people in memory clinics who have at least mild sleep apnoea (Oxygen Desaturation Index 4% > 5) according to a single night of overnight polygraphy (WatchPAT). 4. Diagnostic accuracy of STOP-BANG, Epworth Sleepiness scale and extra questions for at least mild sleep apnoea 5. Data completeness for online (or telephone, face-to-face) questionnaires in this population.
Completion date	01/10/2026

Eligibility

Participant type(s)	Patient
Age group	Adult
Lower age limit	18 Years
Sex	All
Target sample size at registration	453
Key inclusion criteria	1. Patient attending an NHS memory clinic at an included recruitment site 2. Adults aged 18 or over 3. Patients who are able to consent for themselves Bloods sub-study only 1. New diagnosis of sleep apnoea 2. Recruited at the Bristol recruitment site 3. Referred to the sleep clinic 4. Consented to optional bloods sub-study when joining the study
Key exclusion criteria	1. Adults without capacity to consent to the research study. 2. Being unwilling to use the WatchPAT device. Bloods sub-study only 1. Being unwilling or unable to travel to the Bristol Brain Centre for blood tests, where blood tests at home are not feasible.
Date of first enrolment	31/10/2025
Date of final enrolment	31/08/2026

Locations

Countries of recruitment

United Kingdom
England

Study participating centres

North Bristol NHS Trust

Southmead Hospital
Southmead Road
Westbury-on-trym
Bristol
BS10 5NB
United Kingdom

Bradford District Care Trust

New Mill
Victoria Road
Shipley
BD18 3LD
United Kingdom

Cornwall Partnership NHS Foundation Trust

Carew House
Beacon Technology Park
Dunmere Road
Bodmin
PL31 2QN
United Kingdom

North East London NHS Foundation Trust

West Wing
C E M E Centre
Marsh Way
Rainham
RM13 8GQ
United Kingdom

Results and Publications

Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Data sharing statement to be made available at a later date
IPD sharing plan	The data-sharing plans for the current study are unknown and will be made available at a later date

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Participant information sheet	Participant information sheet	11/11/2025	11/11/2025	No	Yes

Editorial Notes

09/10/2025: Study's existence confirmed by Health Research Authority (HRA) (UK).