Clinical trial NCT03246022: Characteristics of Obstructive Sleep Apnea Syndrome Related Hypertension and the Effect of Continuous Positive Airway Pressure Treatment on Blood Pressure
Official title: Huai'an First People's Hospital
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Hypertension Secondary
Keywords: blood pressure fluctuation
hypertension
continuous positive airway pressure
intermittent hypixa
oxygen desaturation
Lead sponsor: Huai'an No.1 People's Hospital
Sponsor class: OTHER
Collaborators: name: The First Affiliated Hospital with Nanjing Medical University
First posted: 2017-08-11
Enrollment: 78
Sex: ALL
Minimum age (years): 18
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: 1. age between 18 to 70 yrs;
2. newly diagnosed OSAS without treatment;

Brief summary: Obstructive sleep apnea syndrome (OSAS) causes nocturnal chronic intermittent hypoxia (CIH) that contributes to the development of hypertension. CIH profiles, including the its length, speed and intensity were widely different in individuals. Until recently, the influence of OSAS-related IH profiles on hypertension development has not been fully explored. The present study aimed to investigate the effects of different CIH properties on blood pressure (BP) and short-term blood pressure variability (BPV) in severe OSAS patients.

Continuous positive airway pressure (CPAP) prevents the airway collapse, avoids the occurrence of intermittent hypoxemia and arousal, is the preferred treatment for OSAS and has been widely used in clinical. In theory, CPAP maintains upper airway patency and preserves ventilation, thereby inhibits the chain reaction over activation of the sympathetic nervous system and blood pressure regulating mechanism, thus CPAP treatment have adequate scientific basis to cause a substantial reduction arterial blood pressure, but controlled studies showed either no effect or only a minor decrease in arterial blood pressure by 1.4 and 2.5 mmHg respectively.The current, which type of combination of hypertension OSA patients can obtain the best antihypertensive benefit from CPAP therapy is still under debate.

Detailed description: Nocturnal BP was continuously monitored via measurement of pulse transmit time (PTT). The value of apnea-related systolic BP elevation (△BP) was used to reflect short-term BPV. Beat-to-beat RR interval data were incorporated in polysomnography for heart rate variability analysis. LF/HF band ratio was compared between two groups which used to reflect sympatho-vagal balance. The length of the desaturation event was measured to the nearest 0.5 second (△t). The fall in SpO2 during apnea was calculated as the gap from start of the desaturation to the nadir of the desaturation. The rate of fall in SpO2 was counted as the change in the percentage of SpO2 per second (△SpO2 /△t) and expressed as oxygen desaturation rate (ODR), which reflected the speed and efficacy of oxygen desaturation during an apnea event. One hundred and two severe OSAS subjects were divided into two groups according to the their median ODR: faster ODR and slower ODR.

In addtion,patient were categorized into three groups: Group l: systolic blood pressure index was less than 30% of AHI; Group 2: systolic blood pressure index was less than 60% but more than 30%; Group 3: systolic blood pressure index is more than 60% of AHI. The investigator would compare the effect of CPAP treatment on awake and sleep BP level at the first night and 2 weeks therapy among three groups. Moreover, whether or not the sympathetic-parasympathetic nerve balance and the renin-angiotensin-aldosterone system are different in three groups would also be evaluated. The main purpose of study is to confirm the OSA with hypertension and OSA secondary hypertension are two different concepts. Basis for the clinical treatment, the former, CPAP might have no effect or only a minor decrease in arterial blood pressure, while the latter CPAP treatment might achieve significant antihypertensive effect.

Eligibility criteria: Inclusion Criteria:

1. BP≤180/110mmHg,but≥140/90mmHg
2. without taking oral antihypertensive drugs. Exclusion criteria.

(1) patients who had been hospitalized for cardiac or respiratory exacerbation\<6wk prior to recruiting; (2) with autonomic nervous system diseases or endocrine disorders which might influence BP; (3) unwilling to participate in the study.

Primary outcomes:
measure: awake systolic blood pressure(SBP)changes
timeFrame: change from Baseline Systolic Blood Pressure at 2 weeks
measure: sleep systolic blood pressure(SBP)changes
timeFrame: change from Baseline Systolic Blood Pressure at 2 weeks
measure: sympathetic-parasympathetic nerve balance changes
timeFrame: change from Baseline Systolic Blood Pressure at 2 weeks
measure: renin-angiotensin-aldosterone systemchanges
timeFrame: change from Baseline Systolic Blood Pressure at 2 weeks
measure: AHI changes
timeFrame: change from Baseline Systolic Blood Pressure at 2 weeks
measure: TST90 changes
timeFrame: change from Baseline Systolic Blood Pressure at 2 weeks
measure: oxygen desaturation index（ODI） changes
timeFrame: change from Baseline Systolic Blood Pressure at 2 weeks
measure: event-related systolic blood pressure elevation (△SBP) changes
timeFrame: change from Baseline Systolic Blood Pressure at 2 weeks
measure: systolic blood pressure(SBP)index
timeFrame: change from Baseline Systolic Blood Pressure at 2 weeks
measure: Desaturation rate
timeFrame: one night
Secondary outcomes:
Other outcomes:
Locations:
city: Huai'an
country: China
facility: Department Of Respiratory Medicine,Huai'an First People's Hospital,Nanjing Medical University
state: Jiangsu
Study officials:
affiliation: Department Of Respiratory Medicine,Huai'an First People's Hospital,Nanjing Medical University
name: Zili Meng, Master
role: STUDY_DIRECTOR
References:
citation: Wang N, Meng Z, Ding N, Chen W, Zhang X, Huang M, Xu J. Oxygen desaturation rate as a novel intermittent hypoxemia parameter in severe obstructive sleep apnea is strongly associated with hypertension. J Clin Sleep Med. 2020 Jul 15;16(7):1055-1062. doi: 10.5664/jcsm.8396.