PUSH Plus Protein Pilot for Hip Fracture Patients

Hip fracture is a common problem among older individuals. The goal of current standard of care after hip fracture is to achieve independent, household ambulation 2-3 months after surgery, yet decreased functional ability typically persists well beyond three months and many patients never resume independent ambulation outside the home. Previous research has established that one must be able to walk at least 300 meters (\~330 yards) within 6 minutes to re-establish routine interactions in the community, such as going to the store or to church. In part, this is based on the average distance from handicapped parking spaces into most facilities. Activity and exercise are believed to be of benefit for reducing disability in older adults, yet the majority of older adults does not participate in regular exercise and is not active. This is especially true for older adults following hip fracture after they complete the usual rehabilitation program.

This research study is being done to test a 16-week, multi-part exercise intervention for hip fracture patients that will be supervised by specially trained physical therapists (PTs). The exercise intervention uses a novel machine to provide strength and endurance training in the home. This has been shown in smaller studies to be safe and effective at increasing strength. The purpose of this small pilot study is to test whether adding a protein supplement to the exercise intervention leads to more improvements in a person's ability to walk in their own home and in the local community. With this knowledge, investigators hope to help a greater number of hip fracture patients enjoy a more complete recovery and improved overall health.

In addition to providing important information on adherence, feasibility, and safety, this pilot study of hip fracture patients has the unique advantage of being able to compare data to two recently completed studies where participants received the PUSH intervention without protein supplementation.

A pilot study including 20 older adults who have experienced a hip fracture will be carried out with participants receiving a specific multi-component intervention with protein supplementation (PUSH Plus Protein). Study activities for participants meeting eligibility criteria will take place after post-acute rehabilitation ends, up to 26 weeks after admission to the hospital for hip fracture. Patients age 60 and older who have had surgical repair for hip fracture will be identified in study hospitals or by self-referral and evaluated for eligibility. Following consent to participate, eligible participants will undergo a comprehensive baseline assessment. Participants completing the entire baseline assessment will be eligible to receive the intervention. All participants will receive the PUSH Plus Protein intervention. The follow-up assessment will occur after the intervention is completed, approximately 16 weeks after baseline testing. The primary endpoint will be measured using the Six-Minute Walk Test (SMWT).

Participants in this pilot will receive the same specific multi-component 16-week intervention, PUSH, as participants in the multi-site randomized controlled trial, "Improving Community Ambulation after Hip Fracture (CAP)" (NCT01783704). The purpose of this study is to test whether adding a protein supplement to the PUSH intervention (PUSH Plus Protein) leads to greater improvement in a person's ability to walk in their own home and in the local community compared to the PUSH intervention alone; therefore, data in this pilot study will be compared to data from participants in the CAP study across the three sites who received the PUSH intervention alone (n=105). The working hypothesis is that PUSH Plus Protein will lead to greater improvements in ability to walk in the community compared to PUSH.

Investigators will also compare the effect of PUSH Plus Protein intervention to PUSH intervention alone on secondary outcomes in the CAP study believed to be precursors to community ambulation as shown in Aim 2 below.

Investigators can also compare participants in the pilot study to participants who received PUSH alone in the ancillary study to CAP, "Mechanistic Pathways to Community Ambulation (CAP-MP)" (n=19) to examine whether PUSH Plus Protein has an impact on the mechanistic factors on the pathway to recovery of ambulatory ability after hip fracture (Aim 3).

Aim 1. To test whether PUSH Plus Protein intervention improves community ambulation (as measured by distance walked in six minutes) compared to PUSH intervention alone (from CAP parent study) at the end of 16 weeks.

Aim 2. To assess the effects of PUSH Plus Protein on precursors to community ambulation compared to the PUSH intervention alone (CAP study). To determine the effects of PUSH Plus Protein intervention, compared to PUSH, on several other outcomes in CAP including activities of daily living (ADLs), quality of life, lower-extremity physical performance, increase of ≥ 50 meters in distance walked in six minutes, cognitive status, and nutritional status.

Aim 3. To determine the effects of PUSH Plus Protein intervention on the mechanistic factors compared to PUSH intervention alone (CAP-MP ancillary study). To determine if, at the end of the 16 week intervention, participants in the PUSH Plus Protein intervention, compared to PUSH alone, have: a) greater muscle volume and attenuation (i.e., reduced intra-muscular fat) of the thigh; b) greater lower extremity strength; c) better gait parameters; d) greater bone mineral density and bone strength; e) more bone formation and less bone resorption; and f) lower levels of circulating inflammatory cytokines.

Aim 4. To determine safety and tolerability of delivering the PUSH Plus Protein intervention to hip fracture patients. This pilot study will be used to estimate the sample size requirements for a more definitive study.

Eligibility Criteria:
Inclusion Criteria:

* Closed fracture of proximal femur
* Age 60 or older at time of baseline testing
* Minimal trauma fracture
* Non-pathologic fracture
* Surgical fixation of fracture
* Living in the community at time of fracture
* Ambulating without human assistance 2 months prior to fracture
* Unable to walk 300 m or more in 6 minutes without human assistance at time of baseline testing

Exclusion Criteria:

* Not English speaking
* Does not live within reasonable distance of the clinical center
* End stage renal disease on dialysis
* Recent myocardial infarction
* Uncompensated congestive heart failure
* Lower extremity amputation
* Symptoms of angina pectoris
* Chest pain or shortness of breath (including from severe COPD)
* Participant plans to move out of area or otherwise be unavailable during the 16-week intervention period
* Participation in another clinical trial
* Not community-residing (e.g., resident of a skilled nursing facility) at time of baseline testing
* Not fully weight-bearing on fractured leg or non-fractured leg at time of baseline testing
* Calculated creatinine clearance \< 15 ml/min
* Serum albumin \< 2.5 g/dl
* Hemoglobin \< 9 g/dl
* Receiving physical therapy for the hip fracture in the hospital or inpatient rehabilitation facility at time of baseline testing
* Severely diminished lower extremity sensation or ulceration
* Uncontrolled hypertension
* Chronic kidney disease
* Severe liver disease (e.g., hepatitis, fatty liver disease, cirrhosis)
* Poorly controlled and/or insulin-dependent diabetes
* Known dairy allergy
* Denied medical clearance by appropriate medical provider
* Clinical site clinician thinks participant is not a good candidate for study (e.g., not likely to survive study period)
* Cognitive impairment (3MS score \<73)
* Development of chest pain or substantial shortness of breath or ambulating with severe pain during baseline SMWT
* Participant walks less than 4 meters in 40 seconds (\<0.1 m/sec) during baseline SMWT
* Baseline testing not done by 26 weeks post admission for hip fracture
* Final sign-off from study clinician and/or principal investigator is incomplete
* Incomplete baseline data
* Unable to contact participant
* Participant is unable to provide her/his own informed consent
* Participant refuses the study