Study of Hospitalised Patients With Acute Respiratory Conditions

The study will recruit adults who are either admitted to hospital with an acute respiratory condition or are under the care of hospital respiratory outpatient services for a chronic respiratory disease. Acute respiratory presentations may include exacerbations of chronic lung diseases such as chronic obstructive pulmonary disease (COPD), asthma, interstitial lung disease, bronchiectasis and pleural disease, as well as acute respiratory illnesses including pneumonia, respiratory infection and pulmonary embolism. A separate healthy control group without underlying respiratory disease will also be recruited for comparison of selected exploratory measures.

Participants may be recruited during hospital admission or through respiratory outpatient services. Baseline assessments will be completed during hospitalisation or within 90 days of a routine clinical follow-up appointment, depending on the route of recruitment.

Participants recruited during an acute hospital admission may be invited to complete an early post-discharge assessment at approximately 30 days and up to three additional optional follow-up visits during the 12 months after discharge to assess clinical recovery. Participants recruited through respiratory outpatient services will be invited to undergo annual follow-up assessments. Follow-up for the main cohort will continue for up to 36 months, with permitted visit windows of up to 90 days.

Follow-up assessments may be completed by telephone, during a face-to-face research visit at the Biomedical Research Centre, during a research visit for another ethically approved study, or alongside routine clinical follow-up. Participants may choose not to attend further study visits after recruitment without affecting their usual clinical care.

If a participant is admitted to hospital during study follow-up, they may be invited to complete an additional assessment during the acute admission, within 7 days of hospitalisation, followed by up to three further assessments during the subsequent 12 months. Healthcare utilisation and clinical outcome data, including subsequent hospital admissions and treatments, may also be collected remotely from primary and secondary healthcare records.

Study assessments may include clinical characteristics, symptoms, health-related quality of life, frailty, sarcopenia, physical function, muscle strength, lung function, physical activity, body composition, muscle structure and function, physiological measurements, imaging and biological samples. These data will be used to characterise recovery following acute respiratory illness, investigate hospital-associated disability, explore potential biomarkers and develop approaches to risk stratification.

Healthy controls will undergo a baseline assessment only and will provide comparator data for selected exploratory outcomes.

MPES SUB-STUDY:

The Muscle Phenotyping Exploratory Study (MPES) is a sub-study nested within CHESTY and will be conducted at Glenfield Hospital. It is designed to provide more detailed assessment of skeletal muscle structure, function and metabolism using methods that complement the broader clinical phenotyping undertaken in the main CHESTY cohort.

The sub-study has two main aims. First, it will assess the feasibility, safety and tolerability of the additional muscle phenotyping methods, including high-density surface electromyography (EMG), ingested stable isotope tracer methodology and muscle biopsy procedures, in participants with respiratory disease and healthy volunteers. Second, it will use these methods exploratorily to undertake detailed skeletal muscle phenotyping, including assessment of muscle activation and neuromuscular function, skeletal muscle mass, muscle protein synthesis and muscle protein breakdown.

Up to 20 participants will be recruited to each of three groups: patients hospitalised with an acute exacerbation of COPD, patients with stable COPD, and age-comparable control participants without chronic respiratory disease. Participants may be recruited from existing CHESTY participants who have provided appropriate consent or through the same screening and recruitment pathways used for the main CHESTY study.

The MPES sub-study will use the same study site, research team and core assessments as CHESTY, including measures of physical function and muscle strength, questionnaires and muscle biopsy procedures where applicable.