Feasibility of a Home Exercise Program to Manage Post-transplant Metabolic Syndrome

Post-transplant metabolic syndrome (PTMS) affects about 50% liver transplant (OLT) and 25% lung transplant (LTx) recipients at 12-18 months post-transplant. PTMS (comprised of glucose intolerance, obesity, hypercholesterolemia and hypertension) has been associated with increased risk for cardiovascular morbidity and long-term survival. Exercise studies in the early post-transplant period have shown some benefits on PTMS risk factors with facility-based training, but it remains unclear if exercise can be sustained in the home environment with sufficient adherence or training intensity to impact PTMS beyond the early post-transplant period. Objectives: 1) To evaluate the feasibility of a three-month individualized, virtual home-based exercise training program in OLT and LTx recipients starting at 1 year post-transplant. 2) To assess estimates of intervention efficacy on elements of PTMS, insulin resistance, exercise self-efficacy, and health related quality of life (HRQL). Methods: 20 OLT and 20 LTx recipients with 2 or more PTMS risk factors at 12-18 months post-transplant will be randomized to a home-based exercise program versus usual care. The exercise group will undergo aerobic training 3 to 5 times per week with resistance training at least twice weekly over a 12-week period. Exercises will be demonstrated by a qualified exercise professional during the first visit with weekly phone and video calls to guide exercise progression, ease communication and promote exercise self-efficacy and adherence based on guiding behavioral principles. As secondary measures, PTMS, insulin resistance, body composition (optional), HRQL, and assessment of self-efficacy will be assessed at baseline and 12-weeks.

Both LTx and OLT recipients have several common risk factors for PTMS including significant weight gain, immunosuppression, and physical inactivity. These risk factors have been shown to be partly reversible with an active lifestyle. A home-based exercise program may prove to be an effective post-transplant intervention for improving the metabolic profile of transplant recipients.

Primary objective: To evaluate the feasibility (recruitment rate, program adherence, attrition, safety, and participant satisfaction) of a 12 week individualized, virtual home-based aerobic and resistance training program in OLT and LTx recipients that are 12-18 months post-transplant. Secondary objective: To assess estimates of intervention efficacy on elements of PTMS, insulin resistance, exercise self-efficacy, and HRQL.

Hypotheses: We hypothesize that it will be feasible to recruit both OLT and LTx recipients into a home-based exercise program with ≥ 70% adherence to the prescribed exercise dose. Secondary Objective: PTMS risk factors, self-efficacy and HRQL will be improved with a home-based exercise program.

The home-based exercise group will be asked to exercise 3 to 5 times per week (≥ 150 minutes of aerobic exercises at moderate intensity) and to also complete resistance training (resistance bands or free weights) over a 12-week period with the guidance of a qualified exercise professional. The control group will be counselled by a qualified exercise professional on the importance of accumulating at least 150 minutes of moderate physical activity during the first assessment at the beginning of the study. Both groups will also receive physical activity trackers (Fitbit), exercise training or physical activity logs, and a counselling session by the dietitian at the start of the study.

A home-based exercise program may prove to be an effective post-transplant intervention for improving the metabolic profile of transplant recipients. Characterizing the feasibility, adherence, and effect estimates of home-based exercise training constitutes the first key step in promoting a healthy lifestyle in transplant recipients, and supporting the development of future trials aimed at reducing the morbidity associated with PTMS.

Eligibility Criteria:
Inclusion Criteria:

* Adult lung and liver transplant recipients 12 to 18 months post-transplant
* Presence of 2 or more metabolic risk factors (hypertension, hyperlipidemia, diabetes, obesity)

Exclusion Criteria:

* Active cardiovascular disease (recent heart attack, significant coronary artery disease on cardiac catheterization, heart failure, uncontrolled arrhythmias, chest pain, dizziness, or fainting in the last 3 months)
* Neuro-muscular disease or orthopedic limitations
* Physically active with ≥ 150 minutes/week of moderate-intensity aerobic physical activity
* Residing outside the province of Ontario