The Role of Physical Activity and Diet Within Pulmonary Sarcoidosis

This is a prospective cross-sectional observational project, with no intervention. All data will be self-reported and self-referred for voluntary participation. The participant information sheet and consent form will be provided in advance following interest of participation from the volunteers via email. In addition, on voluntary consent and approval of participation, the participant's general practitioner (GP) or consultant will be informed of their involvement in the study. Participants will be recruited via online forums, social media sources and via the newsletters /communication from Sarcoidosis organisations and Charities (e.g. The Sarcoidosis Charity; Sarcoidosis UK, Breathing Matters). Travel cost reimbursement will be offered to all participants who attend lab visits.

During visit one, participants will sign informed consent forms and have any questions answered before continuing. Baseline characteristics such as anthropometric data (stature, mass, heart rate (HR), blood pressure, age, BMI, fat% (Bodpod, Cosmed/ Bioelectric Impedance Analysis (BIA), Tanita) will be collected. Following this, participants will conduct a lung function test via computer spirometry (Oxycon Pro, VIASYS GmbH, Eric Jaeger, Hoechberg, Germany) and their predicted results will be corrected for ethnicity, allowing an accurate percentage of lung function to be recorded (Caucasian results remain the same, whilst Black-Caribbean are decreased by 13%). Participants will then conduct muscle strength testing of key muscle groups using an isokinetic dynamometer (Biodex System 4,Biodex Corporation, NY, USA); tests include: elbow flexor muscle strength (EFMS), quadriceps peak torque (QPT) and hamstring peak torque (HPT), in addition to this handgrip strength will also be assessed via handgrip digital dynamometer (Accord Medical Products; appendix XII). A minimum rest period of 20 minutes will follow based on exercise-based pulmonary rehabilitation research. Heart rate (bpm) will be checked at the end of this period and in two minute intervals until HR returns to baseline as per American College of Sport Medicine (ACSM) guidelines. Physical testing will not take place until this return to baseline. Following this rest period, participants will conduct a six-minute walk test (6MWT; appendix VIII). During the test participants will be measured for Borg rate of perceived exertion (appendix IX) and Borg Dyspnoea (appendix X) at 2 minute intervals and at completion of the test. Oxygen saturation (SO2) levels of participants will be recorded during the 6MWT via a portable pulse oximeter. Once the 6MWT has been completed participants will complete three questionnaires, the fatigue assessment scale (FAS; appendix IV), international physical activity questionnaire (IPAQ; appendix V) and Sarcoidosis Health Questionnaire (SHQ; Cox et al., 2003; appendix III). Before leaving, participants will be given a tri-axial accelerometer to wear on their hip (GT3X+ accelerometer, Actigraph) via a belt clip, which will be used to measure the participant's physical activity (PA) for seven days, to establish habitual physical activity levels and compare against the results of the IPAQ.

During the second lab visit, participants will return their accelerometers and following the same pattern of testing as the first visit, excluding the questionnaires (SHQ, FAS & IPAQ) and anthropometric information. The order of testing will follow ACSM guidelines therefore strength and aerobic/anaerobic capacity will be first. Alongside this, age-matched healthy participants with no known interstitial lung disease (ILD) or other condition linked to reduced physical activity will used as a comparison between sarcoidosis and healthy normative values.

Procedural details:

• Six Minute Walk Test: Performed along a straight flat 30 metre course indoors, participants walk at their own pace for 6 minutes. No warm-up is required however participants rest in the seated 10 minutes before the test in accordance with American Thoracic Society guidelines.
• International Physical Activity Questionnaire (IPAQ): IPAQ comprises of 27 items across five activity domains asked independently.
• Fatigue Assessment Scale (FAS): - FAS is a 10-item questionnaire with a 5-point Likert scale, it is split into 5 physical fatigue and 5 mental fatigue questions.
• Sarcoidosis Health Questionnaire (SHQ): SHQ is a 29-item questionnaire with a 7-point Likert scale.
• Borg rate of perceived exertion and Borg Dyspnoea: The Borg rate of perceived exertion scale (Borg RPE) allows participants to express how exerted they feel via a numbered scale, modified Borg Dyspnoea scale (Borg DS) allows participants to express their shortness of breath.
• Distance Saturation Product (DSP): DSP is calculated by multiplying the distance a participant walks against their lowest oxygen saturation (Sp02) recorded during the 6MWT.
• Oxygen saturation levels (SpO2): Oxygen saturation levels of participants will be recorded during the 6MWT via a portable pulse oximeter, the device will be fitted to the participant's finger and checked every 30 seconds throughout.
• Isokinetic Dynamometer: A Biodex system will be utilized to look at dominant upper and lower limb strength via elbow flexor muscle strength (EFMS), quadriceps peak torque (QPT) and hamstring peak torque (HPT) tests, with rest periods of 60 seconds between repeated tests as per previous research findings.
• Hand Dynamometer: Utilised to measure hand grip strength following ACSM guidelines.
• Tri-axial Accelerometer: Participants will keep this on their persons throughout the time between their lab visits to measure real world physical activity for seven days.