Study name: Screening, Diagnosis and Treatment of Obstructive Sleep Apnea Syndrome in Hypertensive Patients in China: A Prospective National Multi-center Registry.

Rationale: Obstructive sleep apnoea syndrome (OSAS) is a common secondary cause of hypertension and significantly correlated with the risk of cardiovascular and cerebrovascular diseases. However, continuous positive airway pressure (CPAP) only shows modest blood pressure lowering effect, although it is effective in the relieve of daytime sleepiness and other symptoms of OSAS. One of the possible reasons for the low antihypertensive efficacy might be the low adherence to CPAP therapy. Nonetheless, few studies systematically investigated CPAP adherence with regard to its prediction and clinical relevance for cardiovascular protection and prevention.

Objective: 1) To evaluate short- and long-term CPAP adherence in patients with hypertension and obstructive sleep apnea syndrome; 2) To investigate the predictors of short- and long-term CPAP adherence; 3) To explore the correlation between the CPAP adherence and blood pressure, target organ damage and the incidence of cardiovascular and cerebrovascular events.

Study design: Prospective, multi-center, observational study.

Study population: Patients with hypertension who are suspected to have obstructive sleep apnea syndrome due to snoring, daytime sleepiness and other related symptoms are considered eligible and should meet the following criterias: 1) Agree to participate in the study and sign the informed consent; 2) At least 18 years old; 3) STOP-Bang questionnaire, score ≥3 points; 4) Complete polysomnography in hospital; 5) Currently on CPAP therapy.

Follow up: 3, 6 and 12 months after registry.

Sample size estimation: At least 633 patients.

Timeline: Start of subjects' enrollment: Jan 2023; End of subjects' enrollment: December 2026; End of study: December 2026.

Organization: The Centre for Epidemiological Studies and Clinical Trials, Ruijin Hospital, Shanghai, China.

Study name: Screening, Diagnosis and Treatment of Obstructive Sleep Apnea Syndrome in Hypertensive Patients in China: A Prospective National Multi-center Registry.

Rationale: Obstructive sleep apnoea syndrome (OSAS) is a common secondary cause of hypertension and significantly correlated with the risk of cardiovascular and cerebrovascular diseases. However, continuous positive airway pressure (CPAP) only shows modest blood pressure lowering effect, although it is effective in the relieve of daytime sleepiness and other symptoms of OSAS. One of the possible reasons for the low antihypertensive efficacy might be the low adherence to CPAP therapy. Nonetheless, few studies systematically investigated CPAP adherence with regard to its prediction and clinical relevance for cardiovascular protection and prevention.

Objective: 1) To evaluate short- and long-term CPAP adherence in patients with hypertension and obstructive sleep apnea syndrome; 2) To investigate the predictors of short- and long-term CPAP adherence; 3) To explore the correlation between the CPAP adherence and blood pressure, target organ damage and the incidence of cardiovascular and cerebrovascular events.

Study design: Prospective, multi-center, observational study.

Study population: Patients with hypertension who are suspected to have obstructive sleep apnea syndrome due to snoring, daytime sleepiness and other related symptoms are considered eligible and should meet the following criterias: 1) Agree to participate in the study and sign the informed consent; 2) At least 18 years old; 3) STOP-Bang questionnaire, score ≥3 points; 4) Complete polysomnography in hospital; 5) Currently on CPAP therapy.

Follow up: 3, 6 and 12 months after registry.

Sample size estimation: At least 633 patients.

Timeline: Start of subjects' enrollment: Jan 2023; End of subjects' enrollment: December 2026; End of study: December 2026.

Organization: The Centre for Epidemiological Studies and Clinical Trials, Ruijin Hospital, Shanghai, China.

Inclusion Criteria:

1. Agree to participate in the study and sign the informed consent;
2. At least 18 years old;
3. STOP-Bang questionnaire, score ≥3 points;
4. Complete polysomnography in hospital;
5. Currently on CPAP therapy.

Exclusion Criteria:

1. Clinic systolic/diastolic blood pressure ≥180/110 mmHg;
2. Previous or current treatment for OSAS without CPAP;
3. Severe respiratory diseases such as chronic obstructive pulmonary disease, or contraindications to CPAP therapy, such as pneumothorax, pulmonary bulla and new-onset stroke；
4. Sleep disorders or insomnia;
5. Intolerance of CPAP therapy;
6. Patient with cognitive dysfunction who are unable to provide informed consent;
7. Other circumstances that patients are not appropriate for the study upon the investigator's judgment.

Patients with hypertension who are suspected to have obstructive sleep apnea syndrome due to snoring, daytime sleepiness and other related symptoms are considered eligible and should meet all the inclusion criterias but not any of the exclusion criterias.