he Effect of Altitude and Simulated Flight in a Hypobaric Chamber on Glucose Metabolism and the in Vivo Performance of Insulin Delivery Systems

University of Surrey2 个研究点分布在 1 个国家目标入组 12 人开始时间: 2023年1月28日最近更新: 2024年12月17日

适应症

试验速览

阶段: 不适用
状态: 已完成
发起方: University of Surrey
入组人数: 12
试验地点: 2
主要终点: Postprandial endogenous glucose production

研究概览研究设计入排标准结局指标研究者研究点记录与标识符相似试验

研究概览

简要总结

Atmospheric pressure can influence how the body handles blood glucose. At high elevations, atmospheric pressure decreases. Research shows that both the elevation and the length of stay at that elevation can influence the body's glucose response.

The investigators would like to find out if the change in pressure in the cabin environment during a flight affects the body's handling of glucose. Commercial planes usually fly at 40000 feet (12192 m) but the cabin pressure is re-pressurized to 8000 feet (2438 m) with cabin pressure fixed at 560 mmHg. The normal atmospheric pressure at sea level is 760 mmHg.

Since the investigators cannot perform the studies in an aeroplane, a hypobaric chamber will be used to set to this low pressure which will reproduce the cabin environment during a commercial flight. The chamber is located at the research and development company, QinetiQ, MOD Boscombe.

The objective of this study is to compare the effect of atmospheric pressure on glucose metabolism during simulated flight conditions during fasting and in response to a mixed liquid meal.

This will involve attending three visits; visit 1 (screening), visit 2 and visit 4 and two phone visits. The duration of the study is 15 days or 1 month depending on the participant's availability. Visit 1, informed consent and screening, will take place at CEDAR, Royal Surrey County Hospital, Guildford, followed by two visits of the meal test in random order at CEDAR or QintetiQ, Visit 2, will be a meal test performed at 760 mmHg OR at 560mmHg. Visit 4, will be a further meal test at 560 mmHg OR 760 mmHg. The order of the meal test visits at different ambient pressures will be randomised. The two phone visits will take place the day after the meal test days to enquire about the patient's health after the test.

详细描述

The study is a randomised crossover study at two different ambient pressures one at normal ambient pressure (760 mmHg) and the other at 560 mmHg mimicking the repressurised cabin environment at 8000 feet. Participants will have three visits and two phone visits. Visit 1 is the screening visit, Visit 2, will be a meal test (MT) performed at 760 mmHg OR at 560mmHg. Visit 4, will be a further MT at 560 mmHg OR 760 mmHg. The order of MT test visits at different ambient pressures will be randomised. The two phone visits will take place the day after the MT assessment days (visit 3 and 5) with prior arrangement to enquire about the patient's health after the test. The expected duration of participant participation is approximately 15 days.

Screening visit 1 can also be performed before the first test meal on the visit 2 before any visit 2 activities can take place.

Randomisation procedure: The participant will be assigned a study identification number and randomised for the study procedures in random order at different ambient pressures at 760 mmHg and 560 mmHg. Randomisation for the order of the two meal studies, ie at 760 mmHg and at 560mmHg will take place at recruitment phase to accommodate the availability of the volunteers and the dates available at QinetiQ facility for the meal studies.

The recruitment phase will commence as soon as there is ethical, HRA, research governance and regulatory approval and only after the Sponsor 'green light' has been issued.

Recruitment:

研究设计

研究类型: Interventional
分配方式: Randomized
干预模型: Crossover
主要目的: Basic Science
盲法: None

入排标准

年龄范围: 18 Years 至 65 Years（Adult, Older Adult）
性别: All
接受健康志愿者: 否

入选标准

•Able in the opinion of the investigator, and willing to give informed consent obtained before any study-related activities.
•Type 1 diabetes
•Duration of type 1 diabetes greater than 12 months.
•Current treatment insulin pump therapy.
•Male or female aged 18 - 65 years.
•BMI of less than 30 kg/m
•HbA1c of less than 9%.
•Able and willing to complete the study.
•No cardiovascular complications
•No significant past respiratory disease
•No chronic (long-term) ENT disease such as vertigo, sinusitis or perforated ear drum
•Fitness to undertake long haul airliner flight as a passenger, without assistance or any form of medical support (e.g. supplementary oxygen)
•Patients who are or who have previously been involved in research are eligible provided they have not received an investigational drug within one month of entry into the study

排除标准

•Outside of stated age range.
•Female who is pregnant, breast feeding or intends to become pregnant or is of child-bearing potential and not using an adequate contraceptive method (adequate contraceptive measures as required by local regulation or practice).
•Participation in any clinical trial of an investigational medicinal product within 30 days before screening.
•Inability to understand verbal and / or written explanations given in English.
•Proliferative retinopathy that has required acute treatment within last three months.
•History of severe renal impairment.
•History of unstable or rapidly progressing renal disease.
•History of hepatic insufficiency / and or significant abnormal liver function.
•Positive serologic evidence of current infectious liver disease including Hepatitis B viral antibody IGM, Hepatitis B surface antigen and Hepatitis C virus antibody.
•Congestive heart failure defined as New York Heart Association (NYHA) class III and IV, unstable or acute congestive heart failure. Note: eligible patients with congestive heart failure, especially.
•Myocardial infarction, stroke, hospitalization for unstable angina pectoris or transient ischaemic attack within 180 days prior to the day of screening.
•Uncontrolled cardiac arrhythmias.
•Uncontrolled hypertension. (BP greater than 160/90).
•Exclude any ENT disease that might interfere with ventilation of the middle ear cavity ('ear clearing') or sinuses
•Any ENT surgery in last 6 months
•Any recent open surgery (last month)
•Claustrophobia
•Inability to communicate over a headset/microphone system
•Intolerance to milk products and those who follow a vegan diet