Obesity, Osteoarthritis
Conditions
Keywords
older adults, body composition, weight loss, muscle mass
Brief summary
The purpose of this research study is to see whether wearing a weighted vest during a period of active weight loss can decrease the loss of muscle and bone that occurs during weight loss. We will also determine if study participants who wear the weighted vest will have greater improvements in physical function and self-reported disability, pain, stiffness, fatigue and quality of life. This knowledge could impact weight loss programs designed for older adults. Hypothesis: Participants randomized to VEST will experience similar weight loss, but less loss of lean mass and bone density, than participants randomized to Control.
Detailed description
The loss of muscle mass and bone density during weight loss is partially attributed to the decrease in mechanical stress on these tissues as weight is reduced. As a result, performing exercises that enhance muscle and gravitational loading during the period of caloric restriction usually diminishes the relative amount of muscle and bone loss for a given weight loss, but these interventions do not fully prevent all muscle and bone loss.In addition, conventional exercise training interventions often require expensive equipment, on-site participation, and, ideally for older, obese adults, safety supervision by trained exercise leaders. Moreover, the exercises performed may not fully translate into improvement in daily tasks due to training specificity, and are not always tolerated or sustained, especially in obese persons with OA. On the other hand, it is conceivable that treating the decrease in mechanical load from weight loss by externally replacing lost weight via use of a weighted vest may also be effective for reducing muscle and bone loss during caloric restriction. In animal models, mechanisms regulating skeletal tissue structure and function respond in a similar fashion to increases in actual or externally-added body mass. Also, research shows that exercising while wearing weighted vests can improve bone density, muscle mass, and lower extremity strength in older adults. However, no prior studies have examined the effects of weighted vest use on muscle mass and bone density during a period of intentional weight loss. The main objective of this pilot study is to assess feasibility (accrual, retention, compliance) of daily use of a weighted vest during a diet intervention, to estimate the variability of outcome measures, and to obtain preliminary estimates of treatment efficacy. A controlled, randomized design will be used so we can obtain a realistic estimate of accrual and an unbiased estimate of treatment efficacy. A total of 36 older (age=65-79 yrs), obese (BMI=30-40 kg/m2), sedentary men and women with x-ray evidence of knee OA will undergo a 22 week weight loss intervention (targeting 10% weight loss) with randomization to one of two groups (n=18/grp): 1) No vest use (Control); or 2) Progressive weighted vest use during normal daily activities (VEST).
Interventions
BEHAVIORALVest
light weight, adjustable, vest to be worn underneath clothes that weight can be added to
BEHAVIORALDiet
Participants will undergo a 22 week dietary weight loss intervention which will incorporate dietary practices for achieving weight loss while minimizing muscle and bone loss. Participants will be instructed by the Registered Dietitian to follow a low calorie diet. Individual calorie goals will be adjusted during the study if necessary to achieve a targeted weight loss goal of at least 8%, but no more than 12%, within the intervention time frame.
Sponsors
Medifast, Inc.
Wake Forest University Health Sciences
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
65 Years to 79 Years
Healthy volunteers
Yes
Inclusion criteria
* BMI=30-40 kg/m2; Wt\<135 kg, * self- reported MD diagnosis of osteoarthritis * No evidence of clinical depression or other contraindications for participation in voluntary weight loss, * Sedentary lifestyle (\<30 min, 3 d/wk of exercise), * Able to provide own transportation to study visits and intervention, * Not dependent on a cane or walker, * Willing and able to consume meal replacement products, * Not involved in other research study, * Approved for participation by Medical Director, * Willing to provide informed consent.
Exclusion criteria
* Weight loss or gain (±5%) in past 6 mos, * Excessive alcohol use (\> 14 drinks/wk), * Smoker (\>1 cigarette/d or 4/wk within yr), * Evidence of cognitive impairment (MoCA score \<22) or difficulty with hearing or vision that would interfere with study participation, Insulin-dependent or uncontrolled diabetes (FBG \>125 mg/dl) or Hypertriglyceridemia (TG\>400 mg/dl), * Osteoporosis (T-score\< -2.5 on hip or spine); Hip fracture, joint replacement, or spinal surgery in past 6 mos, or hyperkyphosis, * Uncontrolled hypertension (BP\>160/90 mmHg) or abnormal kidney or liver tests per Medical Director discretion, * Self- reported hepatitis B or C, * Severe anemia (Hb\<10 g/100 ml), * Past or current uncontrolled endocrine/metabolic disease, neurological or hematological disease, fibromyalgia, chronic pulmonary disease, hyperparathyroidism, rheumatoid arthritis, unstable angina, MI, cardiac surgery within 3 months, * Cancer requiring treatment in past year except non-melanoma skin cancers, * Regular use of medications that may influence body weight, hormones, weight loss medications, bone remodeling medication, prior use of medications that affect bone, insulin-dependent, * Unable to tolerate vest run-in.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Lean Mass Measured by DXA | Baseline and 22 weeks | Lean body mass (Whole body and lower-extremity lean mass are used in total calculation). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Hip Bone Density | Basleine and 22 weeks | Hip bone density as measured by DXA. |
| Changes in Self-report on Fatigue Using Pittsburgh Fatigability Scale (PFS) | baseline and 22 weeks | Pittsburgh Fatigability Scale (PFS) is a self-administered 10 item assessment. It asks participants to rate the level of physical and mental fatigue they experience or imagine after completing a set of hypothetical activities related to daily life at a fixed intensity and duration. The participant provides a score from 0-5 where 0' equals no fatigue at all, and 5 equals extreme fatigue. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Change in Body Weight | Baseline and 22 weeks | Body weight |
| Changes in Lower Extremity Physical Function | Baseline and 22 weeks | SPPB is a measure of lower-extremity function consisting of walking speed, balance, and repeated chair stands. These 3 performance measures are scored from 0 to 4, with 4 indicating the highest level of performance and 0 the inability to complete the task, with a summary score of 0-12.The SPPB has been shown to have predictive validity showing a gradient of risk for mortality, nursing home admission, and disability. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Vest + Diet All participants will undergo a 22 week dietary weight loss. In addition, participants will be asked to wear a weighted vest for \>10 hours a day. Weight in the vest is adjusted to match weight lost during the intervention.
Vest: light weight, adjustable, vest to be worn underneath clothes that weight can be added to
Diet: Participants will undergo a 22 week dietary weight loss intervention which will incorporate dietary practices for achieving weight loss while minimizing muscle and bone loss. Participants will be instructed by the Registered Dietitian to follow a low calorie diet. Individual calorie goals will be adjusted during the study if necessary to achieve a targeted weight loss goal of at least 8%, but no more than 12%, within the intervention time frame. | 20 |
| No Vest + Diet All participants will undergo a 22 week dietary weight loss intervention. Participants in this group will be asked not to change their daily habits other than adherence to the diet protocol.
Diet: Participants will undergo a 22 week dietary weight loss intervention which will incorporate dietary practices for achieving weight loss while minimizing muscle and bone loss. Participants will be instructed by the Registered Dietitian to follow a low calorie diet. Individual calorie goals will be adjusted during the study if necessary to achieve a targeted weight loss goal of at least 8%, but no more than 12%, within the intervention time frame. | 17 |
| Total | 37 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Adverse Event | 1 | 0 |
| Overall Study | Lost to Follow-up | 0 | 1 |
| Overall Study | Withdrawal by Subject | 1 | 1 |
Baseline characteristics
| Characteristic | Vest + Diet | Total | No Vest + Diet |
|---|---|---|---|
| Age, Continuous | 70.3 years STANDARD_DEVIATION 3.4 | 70.1 years STANDARD_DEVIATION 3 | 69.9 years STANDARD_DEVIATION 2.6 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants | 0 Participants | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 20 Participants | 37 Participants | 17 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 4 Participants | 9 Participants | 5 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 16 Participants | 28 Participants | 12 Participants |
| Region of Enrollment United States | 20 participants | 37 participants | 17 participants |
| Sex: Female, Male Female | 15 Participants | 29 Participants | 14 Participants |
| Sex: Female, Male Male | 5 Participants | 8 Participants | 3 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 20 | 0 / 17 |
| other Total, other adverse events | 15 / 20 | 10 / 17 |
| serious Total, serious adverse events | 2 / 20 | 2 / 17 |
Outcome results
Primary
Change in Lean Mass Measured by DXA
Lean body mass (Whole body and lower-extremity lean mass are used in total calculation).
Time frame: Baseline and 22 weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Diet+Vest | Change in Lean Mass Measured by DXA | -2.9 Kg | Standard Deviation 1.6 |
| No Vest+Diet | Change in Lean Mass Measured by DXA | -2.3 Kg | Standard Deviation 1.9 |
Secondary
Change in Hip Bone Density
Hip bone density as measured by DXA.
Time frame: Basleine and 22 weeks
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Diet+Vest | Change in Hip Bone Density | -6.1 g/cm2 |
| No Vest+Diet | Change in Hip Bone Density | -18.7 g/cm2 |
Secondary
Changes in Self-report on Fatigue Using Pittsburgh Fatigability Scale (PFS)
Pittsburgh Fatigability Scale (PFS) is a self-administered 10 item assessment. It asks participants to rate the level of physical and mental fatigue they experience or imagine after completing a set of hypothetical activities related to daily life at a fixed intensity and duration. The participant provides a score from 0-5 where 0' equals no fatigue at all, and 5 equals extreme fatigue.
Time frame: baseline and 22 weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Diet+Vest | Changes in Self-report on Fatigue Using Pittsburgh Fatigability Scale (PFS) | 15.3 units on a scale | Standard Deviation 13.6 |
| No Vest+Diet | Changes in Self-report on Fatigue Using Pittsburgh Fatigability Scale (PFS) | 12.3 units on a scale | Standard Deviation 14.6 |
Other Pre-specified
Change in Body Weight
Body weight
Time frame: Baseline and 22 weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Diet+Vest | Change in Body Weight | -110.6 kg | Standard Deviation 5.7 |
| No Vest+Diet | Change in Body Weight | -10.9 kg | Standard Deviation 4.1 |
Other Pre-specified
Changes in Lower Extremity Physical Function
SPPB is a measure of lower-extremity function consisting of walking speed, balance, and repeated chair stands. These 3 performance measures are scored from 0 to 4, with 4 indicating the highest level of performance and 0 the inability to complete the task, with a summary score of 0-12.The SPPB has been shown to have predictive validity showing a gradient of risk for mortality, nursing home admission, and disability.
Time frame: Baseline and 22 weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Diet+Vest | Changes in Lower Extremity Physical Function | 0.1 units on a scale | Standard Deviation 0.34 |
| No Vest+Diet | Changes in Lower Extremity Physical Function | 0.15 units on a scale | Standard Deviation 0.16 |