Diabetes is a major health concern in obese older Veterans, especially in those who are African American. The negative impact of diabetes on muscle and physical function contributes to metabolic as well as physical decline and is under-studied. This randomized controlled trial compares a higher-protein, weight loss regimen previously shown to improve physical function to an Recommended Dietary Allowance (RDA) protein intervention in obese older male Veterans with pre-diabetes and functional limitations. Equal numbers of white and black male Veterans will be studied, filling gaps in the investigators' knowledge of differential responses by race as well as obesity interventions for men in general. The primary outcome is functional performance by Short Physical Performance Battery and secondary measures include muscle quantity and composition, glucose handling, lean body mass, recent falls and fear of falling, and quality of life measured at 0, 3 and 6 months. The goal of this research is to accelerate functional recovery and enhance independence in obese male Veterans, which is strongly aligned with the VA mission to "maximize the physical and social autonomy of Veterans".
This study examines an evidence-based obesity intervention as a means of reducing the impact of prediabetes on muscle function in obese older men of white and black race. A total of 64 obese (BMI 30 kg/m2) male Veterans aged 55 + yrs, with mild to moderate functional impairments (Short Physical Performance Battery score of 4 to 11 units) and prediabetes, will be randomized to a higher-protein weight loss treatment (HP-WL) or an RDA-level protein control weight loss treatment (C-WL). All participants receive individualized calorie prescriptions calculated to achieve a weight loss of \~1-2 pounds per week and attend weekly group support sessions designed to enhance diet compliance with goal setting, self-monitoring, stress management, and daily diet journaling. They will also attend a weekly low impact, chair exercise class. HP-WL participants are provided a supply of chilled/frozen high-quality protein foods (lean meats, low fat dairy products) sufficient to give 30 g high quality protein for two of three meals daily to help assure diet compliance. C-WL participants are provided 1 serving per day of high quality protein to avoid unintentional bias. Treatment responses will be compared for the primary outcome of functional performance by Short Physical Performance Battery and important secondary measures, including muscle quantity and composition, glucose handling, lean body mass, recent falls and fear of falling, and quality of life at 0, 3 and 6 months. An exploratory aim examines potential mediators of racial differences in treatment responses and documents the most successful intervention strategies. This randomized controlled trial of a balanced, higher-protein diet during a metabolic challenge (caloric restriction) in those with prediabetes also considers racial differences in responses of obese older men to this regimen. Study findings will fulfill the RR\&D mission by advancing interventions to improve physical function in older Veterans, yield novel information about the impact of balanced, higher protein on muscle and glucose handling, and explore racial differences in responses to obesity interventions.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
SINGLE
Enrollment
105
Along with a weight reduction diet (by instruction), participants will receive high quality protein foods provided to them to include in their daily diet (see study arm description).
Durham VA Medical Center, Durham, NC
Durham, North Carolina, United States
Total Short Physical Performance Battery (SPPB) Score at Baseline
SPPB total score is the sum of scores from 3 measures, namely balance, gait speed, and chair stands. Score scale 0-12. Higher numbers indicate higher functioning.
Time frame: 0 months
Change in Total Short Physical Performance Battery (SPPB) Score at 3 Months
SPPB total score is the sum of scores from 3 measures, namely balance, gait speed, and chair stands. Score scale 0-12. Higher numbers indicate higher functioning. The change score is determined by the value at 3 months minus the value at baseline.
Time frame: Baseline and 3 months
Change in Total Short Physical Performance Battery (SPPB) Score at 6 Months
SPPB total score is the sum of scores from 3 measures, namely balance, gait speed, and chair stands. Score scale 0-12. Higher numbers indicate higher functioning. The change score is determined by the value at 6 months minus the value at baseline.
Time frame: Baseline and 6 months
Percent Change in Body Weight at 3 Months
Body weight was measured on the same scale, with light clothing and no shoes, measured to nearest 0.1 lbs. Percent change in body weight was calculated by subtracting weight at 3 months from weight at baseline, dividing by weight at baseline, and multiplying by 100.
Time frame: Baseline and 3 months
Percent Change in Body Weight at 6 Months
Body weight was measured on the same scale, with light clothing and no shoes, measured to nearest 0.1 lbs. Percent change in body weight was calculated by subtracting weight at 6 months from weight at baseline, dividing by weight at baseline, and multiplying by 100.
Time frame: Baseline and 6 months
Change in 6 Minute Walk Test (Aerobic Endurance) at 3 Months
Meters walked in six minutes on a designated course. Change in meters walked was calculated by subtracting meters walked at 3 months from meters walked at baseline.
Time frame: Baseline and 3 months
Change in 6 Minute Walk Test (Aerobic Endurance) at 6 Months
Meters walked in six minutes on a designated course. Change in meters walked was calculated by subtracting meters walked at 6 months from meters walked at baseline.
Time frame: 6 months
Change in Timed 8-ft Up and Go (Agility/Dynamic Balance) at 3 Months
Begins seated. On word 'go' stands, walks around a cone 8 feet away, returns to seated. Timing starts on 'go' and ends when seated. Change in time walked was calculated by subtracting time walked at 3 months from time walked at baseline.
Time frame: Baseline and 3 months
Change in Timed 8-ft Up and Go (Agility/Dynamic Balance) at 6 Months
Begins seated. On word 'go' stands, walks around a cone 8 feet away, returns to seated. Timing starts on 'go' and ends when seated. Change in time walked was calculated by subtracting time walked at 6 months from time walked at baseline.
Time frame: Baseline and 6 months
Change in Number of Chair Stands in 30 Seconds (Lower Body Strength) at 3 Months
With arms across chest, stand up completely and return to seated as many times as possible in 30 seconds. Change in number of chair stands was calculated by subtracting number of chair stands at 3 months from number of chair stands at baseline.
Time frame: Baseline and 3 months
Change in Number of Chair Stands in 30 Seconds (Lower Body Strength) at 6 Months
With arms across chest, stand up completely and return to seated as many times as possible in 30 seconds. Change in number of chair stands was calculated by subtracting number of chair stands at 6 months from number of chair stands at baseline.
Time frame: Baseline and 6 months
Change in Isokinetic Knee Extension Peak Torque (Muscle Strength) at 3 Months
Knee extensor at 60 degrees with a dynamometer. Average peak torque for three trials will be recorded. Change in peak torque was calculated by subtracting peak torque at 3 months from peak torque at baseline.
Time frame: Baseline and 3 months
Change in Isokinetic Knee Extension Peak Torque (Muscle Strength) at 6 Months
Knee extensor at 60 degrees with a dynamometer. Average peak torque for three trials will be recorded. Change in peak torque was calculated by subtracting peak torque at 6 months from peak torque at baseline.
Time frame: Baseline and 6 months
Change in Isometric Hand Grip (Upper Body Strength) at 3 Months
Using the Jamar Hand Dynamometer, the amount of pressure placed when squeezing the instrument as hard as possible was measured. Two trials per hand were measured. Change in hand grip was calculated by subtracting the highest value at 3 months from the highest value at baseline.
Time frame: Baseline and 3 months
Change in Isometric Hand Grip (Upper Body Strength) at 6 Months
Using the Jamar Hand Dynamometer, the amount of pressure placed when squeezing the instrument as hard as possible was measured. Two trials per hand were measured. Change in hand grip was calculated by subtracting the highest value at 6 months from the highest value at baseline.
Time frame: Baseline and 6 months
Change in Minimal Waist Circumference at 3 Months
Minimal waist circumference was measured at smallest horizontal circumference above umbilicus and below xiphoid process. Change in minimal waist circumference was calculated by subtracting the measurement at 3 months from the measurement at baseline.
Time frame: Baseline and 3 months
Change in Minimal Waist Circumference at 6 Months
Minimal waist circumference was measured at smallest horizontal circumference above umbilicus and below xiphoid process. Change in minimal waist circumference was calculated by subtracting the measurement at 6 months from the measurement at baseline.
Time frame: Baseline and 6 months
Change in Body Composition: Percent Lean Mass at 3 Months
Air displacement plethysmography method (Life Measurement, Inc., Concord, CA). The Cardio Pulmonary, Metabolic and Body Composition (COSMED) BodPod has excellent sensitivity and test-to-test reliability, ease of use, and non-invasive nature, which is important for full participation from this population. Percent lean mass was calculated by the BodPod machine and entered into a REDCap database. Then, change in percent lean mass was calculated by subtracting the percent lean mass at 3 months from the percent lean mass at baseline.
Time frame: Baseline and 3 months
Change in Body Composition: Percent Lean Mass at 6 Months
Air displacement plethysmography method (Life Measurement, Inc., Concord, CA). The Cardio Pulmonary, Metabolic and Body Composition (COSMED) BodPod has excellent sensitivity and test-to-test reliability, ease of use, and non-invasive nature, which is important for full participation from this population. Percent lean mass was calculated by the BodPod machine and entered into a REDCap database. Then, change in percent lean mass was calculated by subtracting the percent lean mass at 6 months from the percent lean mass at baseline.
Time frame: Baseline and 6 months
Change in Body Composition: Percent Fat Mass at 3 Months
Air displacement plethysmography method (Life Measurement, Inc., Concord, CA). The Cardio Pulmonary, Metabolic and Body Composition (COSMED) BodPod has excellent sensitivity and test-to-test reliability, ease of use, and non-invasive nature, which is important for full participation from this population. Percent fat mass was calculated by the BodPod machine and entered into a REDCap database. Then, change in percent fat mass was calculated by subtracting the percent fat mass at 3 months from the percent fat mass at baseline.
Time frame: Baseline and 3 months
Change in Body Composition: Percent Fat Mass at 6 Months
Air displacement plethysmography method (Life Measurement, Inc., Concord, CA). The Cardio Pulmonary, Metabolic and Body Composition (COSMED) BodPod has excellent sensitivity and test-to-test reliability, ease of use, and non-invasive nature, which is important for full participation from this population. Percent fat mass was calculated by the BodPod machine and entered into a REDCap database. Then, change in percent fat mass was calculated by subtracting the percent fat mass at 6 months from the percent fat mass at baseline.
Time frame: Baseline and 6 months
Mini-Cog at Baseline Only
To assess for cognitive impairment, the mini cog was used to screen for eligibility at baseline only. The mini cog includes two components - a 3-item recall and a clock drawing. You can score 0-3 points for the 3-item recall, and 0-2 points for the clock drawing. These subscale scores are summed for a total possible score of 5. Subscale scores were not reported, only the total score. The total score is a range of 0-5. The max total score is 5 with 5 being the best score. To be eligible for the study, the total item recall and clock score needed to be 3 or higher.
Time frame: Baseline only
Change in Computerized Axial Tomography (CAT) Scan at 3 Months
Cross sectional area of the thigh to determine thigh muscle mass. Change in area calculated by subtracting area at 3 months from area at baseline.
Time frame: Baseline and 3 months
Change in Computerized Axial Tomography (CAT) Scan at 6 Months
Cross sectional area of the thigh to determine thigh muscle mass. Change in area calculated by subtracting area at 6 Months from area at baseline.
Time frame: Baseline and 6 months
Change in Short Form-36 (SF-36) Health Survey at 3 Months
Quality of Life Questionnaires The SF-36 measures 8 QOL domains which are dichotomized into physical (functioning, role limitations-physical, pain, general health) and mental health (vitality, social functioning, role limitations-emotional, and emotional/mental health). Item scores were converted to a 0-100 point scale; domain scores were derived by averaging individual items within the subscale; and physical composite and mental health composite scores were derived by averaging the four component domains of each. Higher values are indicative of better QOL. Change in score calculated by subtracting score at 3 months from score at baseline.
Time frame: Baseline and 3 months
Change in Short Form-36 (SF-36) Health Survey at 6 Months
Quality of Life Questionnaires The SF-36 measures 8 QOL domains which are dichotomized into physical (functioning, role limitations-physical, pain, general health) and mental health (vitality, social functioning, role limitations-emotional, and emotional/mental health). Item scores were converted to a 0-100 point scale; domain scores were derived by averaging individual items within the subscale; and physical composite and mental health composite scores were derived by averaging the four component domains of each. Higher values are indicative of better QOL. Change in score calculated by subtracting score at 6 months from score at baseline.
Time frame: Baseline and 6 months
Change in Profile of Mood States (POMS) at 3 Months
Mood Questionnaires The 30-item POMS measures mood and mood changes, has low respondent burden, and includes 6 subscales: tension, depression, anger, fatigue, confusion and vigor (all with range 0-20). Total mood disturbance (TMD) is derived from POMS using the following formula, TMD = (Sum of all subscales except vigor) - vigor (range -20 - 100). Change in score calculated by subtracting score at 3 months from score at baseline.
Time frame: Baseline and 3 months
Change in Profile of Mood States (POMS) at 6 Months
Mood Questionnaires The 30-item POMS measures mood and mood changes, has low respondent burden, and includes 6 subscales: tension, depression, anger, fatigue, confusion and vigor (all with range 0-20). Total mood disturbance (TMD) is derived from POMS using the following formula, TMD = (Sum of all subscales except vigor) - vigor (range -20 - 100). Change in score calculated by subtracting score at 6 months from score at baseline.
Time frame: Baseline and 6 months
Change in Center for Epidemiologic Studies Depression Scale (CES-D) at 3 Months
Depression Questionnaires Individuals were coded as positive for depression if they had a CES-D score of 16 and/or had self-report of depression diagnosis at baseline. In addition to the total score, the CES-D includes 4 subscales: depressed affect (range 0-21), positive affect (range 0-12), somatic (range 0-21), and interpersonal (range 0-6). Change in score calculated by subtracting score at 3 months from score at baseline.
Time frame: Baseline and 3 months
Change in Center for Epidemiologic Studies Depression Scale (CES-D) at 6 Months
Depression Questionnaires Individuals were coded as positive for depression if they had a CES-D score of 16 and/or had self-report of depression diagnosis at baseline. In addition to the total score, the CES-D includes 4 subscales: depressed affect (range 0-21), positive affect (range 0-12), somatic (range 0-21), and interpersonal (range 0-6). Change in score calculated by subtracting score at 6 months from score at baseline.
Time frame: Baseline and 6 months
Change in Perceived Stress Scale (PSS) at 3 Months
Stress Questionnaires The PSS assesses the degree to which situations in one's life are considered stressful (range 0-40). Scores ranging from 0-13 would be considered low stress. Scores ranging from 14-26 would be considered moderate stress. Scores ranging from 27-40 would be considered high perceived stress. Change in score calculated by subtracting score at 3 months from score at baseline.
Time frame: Baseline and 3 months
Change in Perceived Stress Scale (PSS) at 6 Months
Stress Questionnaires The PSS assesses the degree to which situations in one's life are considered stressful (range 0-40). Scores ranging from 0-13 would be considered low stress. Scores ranging from 14-26 would be considered moderate stress. Scores ranging from 27-40 would be considered high perceived stress. Change in score calculated by subtracting score at 6 months from score at baseline.
Time frame: Baseline and 6 months
Change in Pittsburgh Sleep Quality Index (PSQI) and 3 Months
Quality of sleep Questionnaires Reported PSQI values include only these six component scores: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, and use of sleeping medication (all with a range 0-3). The PSQI includes a scoring key for calculating a patient's seven subscores, each of which can range from 0 to 3. The subscores are tallied, yielding a "global" score that can range from 0 to 21. A global score of 5 or more indicates poor sleep quality; the higher the score, the worse the quality. Change in score calculated by subtracting score at 3 months from score at baseline.
Time frame: Baseline and 3 months
Change in Pittsburgh Sleep Quality Index (PSQI) and 6 Months
Quality of sleep Questionnaires Reported PSQI values include only these six component scores: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, and use of sleeping medication (all with a range 0-3). The PSQI includes a scoring key for calculating a patient's seven subscores, each of which can range from 0 to 3. The subscores are tallied, yielding a "global" score that can range from 0 to 21. A global score of 5 or more indicates poor sleep quality; the higher the score, the worse the quality. Change in score calculated by subtracting score at 6 months from score at baseline.
Time frame: Baseline and 6 months
Change in Satisfaction With Life Scale (SWLS) at 3 Months
Life Satisfaction Questionnaires The SWLS evaluates global life satisfaction, an important component of subjective well-being (range 5-35). The SWLS is a 7-point Likert scale style response scale. The possible range of scores is 5-35, with a score of 20 representing a neutral point on the scale. Scores between 5-9 indicate the respondent is extremely dissatisfied with life, whereas scores between 31-35 indicate the respondent is extremely satisfied. Change in score calculated by subtracting score at 3 months from score at baseline.
Time frame: Baseline and 3 months
Change in Satisfaction With Life Scale (SWLS) at 6 Months
Life Satisfaction Questionnaires The SWLS evaluates global life satisfaction, an important component of subjective well-being (range 5-35). The SWLS is a 7-point Likert scale style response scale. The possible range of scores is 5-35, with a score of 20 representing a neutral point on the scale. Scores between 5-9 indicate the respondent is extremely dissatisfied with life, whereas scores between 31-35 indicate the respondent is extremely satisfied. Change in score calculated by subtracting score at 6 months from score at baseline.
Time frame: Baseline and 6 months
Change in Hemoglobin A1c at 3 Months
Blood assay (LabCorp). Change in value calculated by subtracting value at 3 months from value at baseline.
Time frame: Baseline and 3 months
Change in Hemoglobin A1c at 6 Months
Blood assay (LabCorp). Change in value calculated by subtracting value at 6 months from value at baseline.
Time frame: Baseline and 6 months
Change in Fear of Falling at 3 Months
"Yes" responses to the question, "Do you have a fear of falling?" Change in number of "yes" answers from baseline to 3 months. Change was calculated by subtracting the number of "yes" answers at 3 months from the number of "yes" answers at baseline.
Time frame: Baseline and 3 months
Change in Fear of Falling at 6 Months
"Yes" responses to the question, "Do you have a fear of falling?" Change in number of "yes" answers from baseline to 6 months. Change was calculated by subtracting the number of "yes" answers at 6 months from the number of "yes" answers at baseline.
Time frame: Baseline and 6 months
Change in Number of Falls at 3 Months
This is an open-ended questionnaire to see the change in number of times a person falls between time points. Change in value calculated by subtracting value at 3 months from value at baseline.
Time frame: Baseline and 3 months
Change in Number of Falls at 6 Months
This is an open-ended questionnaire to see the change in number of times a person falls between time points. Change in value calculated by subtracting value at 6 months from value at baseline.
Time frame: Baseline and 6 months
Change in 3-day Diet Record, Calories, at 3 Months
3-day diet record by multiple pass; analyzed Food Processor (Version 10.13, 2013; ESHA Research). Change in calories calculated by subtracting average daily calories at 3 months from average daily calories at baseline.
Time frame: Baseline and 3 months
Change in 3-day Diet Record, Calories, at 6 Months
3-day diet record by multiple pass; analyzed Food Processor (Version 10.13, 2013; ESHA Research). Change in calories calculated by subtracting average daily calories at 6 months from average daily calories at baseline.
Time frame: Baseline and 6 months
Change in 3-day Diet Record, Protein, at 3 Months
3-day diet record by multiple pass; analyzed Food Processor (Version 10.13, 2013; ESHA Research). Change in protein in grams calculated by subtracting average daily protein in grams at 3 months from average daily protein in grams at baseline.
Time frame: Baseline and 3 months
Change in 3-day Diet Record, Protein, at 6 Months
3-day diet record by multiple pass; analyzed Food Processor (Version 10.13, 2013; ESHA Research). Change in protein in grams calculated by subtracting average daily protein in grams at 6 months from average daily protein in grams at baseline.
Time frame: Baseline and 6 months
Number of Participants Measured Using an Axis Accelerometer (Actigraph)
Actigraph WGT3X-BT is a wearable accelerometer that measures activity counts, step counts, and physical activity intensity. This outcome is the number of participants who participated in this measurement at baseline.
Time frame: Baseline
Number of Participants Measured Using an Axis Accelerometer (Actigraph)
Actigraph WGT3X-BT is a wearable accelerometer that measures activity counts, step counts, and physical activity intensity. This outcome is the number of participants who participated in this measurement at 3 months.
Time frame: 3 months
Number of Participants Measured Using an Axis Accelerometer (Actigraph)
Actigraph WGT3X-BT is a wearable accelerometer that measures activity counts, step counts, and physical activity intensity. This outcome is the number of participants who participated in this measurement at 6 months.
Time frame: 6 months
Change in Glucose Tolerance Test (OGTT) (78-80), Blood
Ingestion of a 75 g glucose load
Time frame: 3 months
Change in Glucose Tolerance Test (OGTT) (78-80), Blood
Ingestion of a 75 g glucose load
Time frame: 6 months
Percent Attendance at Weekly Diet Class Between Baseline and 3 Months
Attendance counted if in person or virtual. Percentage calculated by dividing number of classes attended by number of classes held and multiplying by 100.
Time frame: Baseline and 3 months
Percent Attendance at Weekly Diet Class Between Baseline and 6 Months
Attendance counted if in person or virtual. Percentage calculated by dividing number of classes attended by number of classes held and multiplying by 100.
Time frame: Baseline and 6 months
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