Pathophysiology of Hypoventilation in Obesity and Effects of Bariatric Intervention: PHOEBI Study
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 30
- 试验地点
- 1
- 主要终点
- Degree of change in expiratory flow limitation
研究概览
简要总结
Breathing is impacted by obesity. Early changes are characterised by significant breathing abnormalities during sleep (a condition called sleep disordered breathing, the most common of which is obstructive sleep apnoea). As the breathing changes worsen in severity, it may result in a rise in carbon dioxide levels during daytime causing a condition called obesity hypoventilation syndrome (OHS). The current treatment for obesity related breathing changes include supportive breathing therapy at night, optimisation of associated medical conditions and weight loss.
Weight management is an important part of obesity treatment. Weight loss strategies such as life-style modification do not always work. Weight loss surgery (bariatric surgery) has been shown to be an effective weight management intervention with long-term results. This study aims to understand breathing changes that occurs due to obesity and their resolution after weight loss surgery. The investigators are aiming to recruit participants with sleep disordered breathing who are currently awaiting bariatric surgery. In particular, the investigators are interested in comparing breathing changes in participants with OHS, who have abnormal regulation of their carbon dioxide levels, and participants with sleep disordered breathing with normal CO2 regulation.
Participants will be recruited through outpatient clinics for sleep disordered breathing. The participants will undergo comprehensive breathing assessments on enrolment including an overnight sleep study. Participants will undergo further daytime breathing assessments before and after their bariatric surgery. End of study will be 6 months after surgery - participants will have a final comprehensive breathing assessment including an overnight sleep study to review resolution of their breathing changes. Depending on the wait list time for the bariatric surgery, it is anticipated that participants will be enrolled in the study for 2 years.
研究设计
- 研究类型
- Observational
- 观察模型
- Case Control
- 时间视角
- Prospective
入排标准
- 年龄范围
- 18 Years 至 80 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Patients 18 years or older
- •Patients with significant sleep disordered breathing requiring treatment
- •Patient is being assessed for bariatric surgery for either gastric sleeve or gastric bypass surgery
排除标准
- •Patients with decompensated hypercapnic respiratory failure (pH< 7.3)
- •Chronic hypercapnic respiratory failure due to a cause other than obesity such as neuromuscular, chest wall or airway disease
- •Unstable cardiac disease including coronary artery disease and heart failure
- •Significant co-morbid psychiatric disease requiring anti-psychotic medications
- •Chronic pain syndrome on high dose opioid medications
- •Treatment for drug or alcohol addiction
- •Cognitive impairment that would prevent informed consent
- •Need for long-term renal replacement therapy
- •Patients who undergo bariatric intervention with gastric balloon or gastric band.
结局指标
主要结局
Degree of change in expiratory flow limitation
时间窗: Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery
Explore whether the degree of positional change in expiratory flow limitation can differentiate between eucapnic and hypercapnic patients
Expiratory flow limitation as measured by forced oscillation testing
时间窗: Measurements on enrolment into study; measurements prior to bariatric surgery (once patients has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery
Measurement of expiratory flow limitation at different position including upright, 45 degrees and supine. We will explore whether expiratory flow limitation can differentiate hypercapnic and eucapnic patients
次要结局
- Intra-abdominal pressure(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Daytime neural respiratory drive (para-sternal electromyography measurements)(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Daytime neural respiratory drive (diaphragm electromyography measurements)(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Upper airway collapsibility(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Lung compliance(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Improvement in apnoea-hyponoea index(Before bariatric surgery on enrolment and 6 months after bariatric surgery)
- Closing capacity(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Correlation between closing capacity and expiratory flow limitation(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Correlation between intra-abdominal pressure, closing capacity and expriatory flow limitation(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Quality of life post bariatric surgery with EQ-5D(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Improvement in mean time spent below 90% oxygen saturation during sleep(Before bariatric surgery on enrolment and 6 months after bariatric surgery)
- Nocturnal neural respiratory drive (diaphragm electromyography measurements)(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Symptom change after commencement of medical therapy compared to bariatric surgery measured with Severe Respiratory Insufficiency Questionnaire(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Changes in sleep architecture measured by %slow wave sleep and %REM sleep(Before bariatric surgery on enrolment and 6 months after bariatric surgery)
- Degree of change in closing capacity(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Nocturnal neural respiratory drive (para-sternal electromyography measurements)(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Quality of life post bariatric surgery with SF-36(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Symptom change after commencement of medical therapy compared to bariatric surgery measured with Multi-dimensional dyspnoea profile(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Respiratory muscle strength (maximal inspiratory pressure/maximal expiratory)(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Respiratory muscle strength (SNIP test)(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Symptom change after commencement of medical therapy compared to bariatric surgery measured with Epworth Sleepiness Scale(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Symptom change after commencement of medical therapy compared to bariatric surgery measured with mMRC (modified medical research council) dypnoea score(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Changes in healthcare resource usage in OHS patients post bariatric surgery(6 months pre bariatric surgery and 6 months post bariatric surgery)
- Improvement in mean nocturnal oxygen saturation during sleep(Before bariatric surgery on enrolment and 6 months after bariatric surgery)
- Improvement in daytime CO2 levels(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Improvement in diaphragm function(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)
- Improvement in glycaemic control(Measurements on enrolment into study; measurements prior to bariatric surgery (once patient has a surgery date); measurements 2-4 weeks after bariatric surgery; and end of study measurements 6 months after bariatric surgery)