An 18-year Follow-up Study on OSA in a Population-based Cohort

An 18-year Follow-up Study on Obstructive Sleep Apnoea in a Population-based Cohort

Our research team has established a polysomnography (PSG) quantified population-based paediatric sleep cohort in 2003 for a childhood OSA prevalence study. Subjects were recruited from 13 randomly selected primary schools. All subjects from this original cohort will be invited to join this 18-year follow-up study to repeat the following data collection: questionnaires, anthropometric measurement, sleep study, 24-hour ambulatory blood pressure (ABP) measurement, echocardiography and neurocognitive assessment.

Study Overview

• Status: Completed
• Conditions: Obstructive Sleep Apnea; Neurocognitive Dysfunction; Epidemiology; Cardiovascular Complication; Natural History
• Intervention / Treatment: Other

Detailed Description

Our research team has established a polysomnography (PSG) quantified population-based paediatric sleep cohort in 2003 for a childhood OSA prevalence study. Subjects were recruited from 13 randomly selected primary schools. In each school, two randomly chosen classes from each grade were invited to participate. In the first phase, all parents of children in the randomly selected schools were invited to attend an education forum during which full explanation of the purpose and flow of the study was given. An envelope containing a validated parent proxy OSAS screening questionnaire and consent was then distributed to parents within a week after the forum. From our previous research, a composite symptom score (summation of the scores of these three questions) of 7 or more has 75.4% sensitivity and 80.5% specificity, compared with polysomnography, to detect OSAS among children aged 5-15 years who had attended our paediatric clinics. Children with a composite symptom score of less than 7 were assigned a computer-generated random number and were invited as a control group with a ratio of 1:2 in the second phase. All children belonging to the high risk of OSAS group and the randomly selected subjects at low risk of OSAS were invited to participate the baseline epidemiological study. In total 619 children aged 5-13 years underwent detailed assessments including anthropometric measurements, airway examination, ambulatory blood pressure recording and overnight PSG. 67 children had moderate-to-severe OSA (obstructive apnoea hypopnoea index, OAHI ≥5/h), 199 had mild OSA (OAHI 1 to <5/h), 103 were primary snorers (OAHI <1/h but snore ≥3 nights per week in the past 12 months) and 250 were normal controls (OAHI <1/h and snore <3 nights per week in the past 12 months).(1) All subjects from this original cohort will be invited to join this 18-year follow-up study to repeat the following data collection: questionnaires, anthropometric measurement, sleep study, 24-hour ambulatory blood pressure (ABP) measurement, echocardiography and neurocognitive assessment.

• Study Type: Observational
• Enrollment (Actual): 202

Contacts and Locations

Study Locations

• China
  • Hong Kong, China, 999077
    • Prince of Wales Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

In our current proposal, subjects from the 2003 cohort will be invited to join this follow-up study. Written consent will be obtained from the participants. The study protocol will be conducted in compliance with the Declaration of Helsinki. Ethics approval will be obtained from the Clinical Research Ethics Committee of the Joint Chinese University of Hong Kong - New Territories East Cluster.

Description

Inclusion Criteria:

- Subjects participants from the 2003 cohort

Exclusion Criteria:

• Neuromuscular disease
• Pathological central apnoea
• Severe chronic lung disease with documented hypoxaemia or awake oxygen saturation <92%
• Chronic respiratory failure (unrelated to OSA)
• Acquired upper airway disease/obstruction
• Craniofacial abnormalities (e.g. secondary to trauma and malignancy)

Other arrangement:

• Subjects who have any respiratory illness within 2 weeks of the scheduled follow-up visit will have their assessment re-arranged until they have fully recovered.
• Subjects taking medications that may affect sleep, upper airway patency or blood pressure (for example sedatives, stimulants, antihistamines, and cough medicine) within a week from recruitment will also be rescheduled to participate when they are free from medication use for at least 2 weeks.
• Subjects with hypertension and are on anti-hypertensive therapy are allowed to continue on their medication and the information will be obtained and recorded during data collection.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
OSA status at 18-year follow-up visit	OSA status of the participants at the 18-year follow-up visit	Through study completion, an average of 2 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Factors associated with the persistence or the development of OSA in adulthood	Factors associated with the persistence or the development of OSA in adulthood	Through study completion, an average of 2 years
Ambulatory blood pressure parameters at 18-year follow-up visit	Ambulatory blood pressure parameters as measures of long-term cardiovascular participants of children who had OSA compared to those without OSA	Through study completion, an average of 2 years
Echocardiographic parameters at 18-year follow-up visit	Echocardiographic parameters as measures of long-term cardiovascular outcomes of participants who had OSA compared to those without OSA	Through study completion, an average of 2 years
Neurocognitive function at 18-year follow-up visit	Neurocognitive function outcomes as measures of long-term neurocognitive outcomes of participants who had OSA compared to those without OSA	Through study completion, an average of 2 years

Collaborators and Investigators

• Sponsor: Chinese University of Hong Kong
• Collaborators: Food and Health Bureau, Hong Kong
• Investigators: Study Director: Ching Ching, Kate Dr. CHAN, Chinese University of Hong Kong

Study record dates

Study Major Dates

• Study Start (Actual): October 20, 2021
• Primary Completion (Actual): September 30, 2025
• Study Completion (Actual): September 30, 2025

Study Registration Dates

• First Submitted: October 2, 2021
• First Submitted That Met QC Criteria: October 2, 2021
• First Posted (Actual): October 14, 2021

Study Record Updates

• Last Update Posted (Estimated): December 15, 2025
• Last Update Submitted That Met QC Criteria: December 8, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Hypertension; Obstructive sleep apnea; Sleep disordered breathing; Cardiovascular complication; Neurocognitive dysfunction
• Additional Relevant MeSH Terms: Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Mental Disorders; Respiratory Tract Diseases; Neurocognitive Disorders; Respiration Disorders; Sleep Wake Disorders; Apnea; Sleep Disorders, Intrinsic; Dyssomnias; Hypertension; Sleep Apnea Syndromes; Sleep Apnea, Obstructive; Cognition Disorders
• Other Study ID Numbers: FUOSA 3.1

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: There is not a plan to make IPD available at this moment.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No