Aging is associated with significant declines in muscle mass, strength, and physical performance, all of which lead to disability, loss of independence, and adverse clinical outcomes. Obesity exacerbates these age-related declines in function and is associated with poorer clinical outcomes and quality of life. Weight loss can also worsen age-related loss of muscle mass and decrease bone mineral density. The overall goals of this study are to determine if the short-term functional benefits of intentional weight loss are sustained long-term, and to examine the long-term benefits and risks of weight loss.
Obesity exacerbates age-related declines in function and is associated with poorer clinical outcomes and quality of life. Although clinical trials conducted study teams show that diet-induced weight loss interventions in obese older adults, when combined with exercise, improve body composition and physical and metabolic function in the short-term, the overall safety and long-term benefits of intentional weight loss in older adults remain controversial. Weight loss can also worsen age-related loss of muscle mass and decrease bone mineral density. Because of these concerns, health care providers are reluctant to recommend weight loss in obese older adults. The goal is to determine whether weight loss-induced improvements in body composition and physical and metabolic function observed in short-term clinical trials persist over time is critical to inform geriatric obesity treatment.
Study Type
OBSERVATIONAL
Enrollment
588
Wake Forest Baptist Medical Center
Winston-Salem, North Carolina, United States
400 meter walk time
Participants are instructed to complete the 400 m distance (on a flat indoor surface) as quickly as possible at a maintainable pace and the time to complete the walk is recorded in seconds.
Time frame: Baseline
Short Physical Performance Battery score
The Short Physical Performance Battery (SPPB) is a widely used assessment of lower extremity physical function that consists of 3 standing balance tasks held for 10 seconds each (side-by-side, tandem and semi-tandem), two 4-m walk tests to assess usual gait speed, and 5 repeated chair stands. Each of the three performance measures is assigned a score ranging from 0 (inability to do the test) to 4 (the highest level of performance) and summed to create an SPPB summary score ranging from 0 (worst) to 12 (best).
Time frame: Baseline
Knee extension strength
Maximal isokinetic knee extension strength. Maximal isokinetic knee extension strength will be measured using an isokinetic dynamometer (Biodex) at 60°/sec with the participant sitting and the hips and knee flexed at 90°. The maximum knee extensor strength of the 4 repetitions from trial 2 for the dominant leg will be will be used in analyses unless unable to test the dominant leg (i.e., knee replacement) in which case the non-dominant leg will be used.
Time frame: Baseline
Total body lean mass
Whole body lean mass will be measured by dual-energy X-ray absorptiometry (DXA).
Time frame: Baseline
Appendicular lean mass
Appendicular lean mass will be measured by DXA.
Time frame: Baseline
Total body fat mass
Whole body fat mass will be measured by DXA.
Time frame: Baseline
Total hip BMD
Bone mineral density (BMD) of the total hip will be measured by DXA.
Time frame: Baseline
Femoral neck BMD
Bone mineral density (BMD) of the femoral neck will be measured by DXA.
Time frame: Baseline
Lumbar spine BMD
Bone mineral density (BMD) of the lumbar spine (L1-L4) will be measured by DXA.
Time frame: Baseline
Subcutaneous abdominal fat
Subcutaneous abdominal fat will be measured by computed tomography (CT).
Time frame: Baseline
Visceral abdominal fat
Visceral abdominal fat will be measured by CT.
Time frame: Baseline
Thigh inter-muscular adipose tissue
Thigh inter-muscular adipose tissue will be measured by CT.
Time frame: Baseline
Glucose
Assessed via a standard clinical assay after fasting for at least 8 hours.
Time frame: Baseline
Insulin
Assessed via a standard clinical assay after fasting for at least 8 hours.
Time frame: Baseline
Total cholesterol
Assessed via a standard clinical lipid panel after fasting for at least 8 hours
Time frame: Baseline
HDL cholesterol
Assessed via a standard clinical lipid panel after fasting for at least 8 hours
Time frame: Baseline
LDL cholesterol
Assessed via a standard clinical lipid panel after fasting for at least 8 hours
Time frame: Baseline
Triglycerides
Assessed via a standard clinical lipid panel after fasting for at least 8 hours
Time frame: Baseline
Systolic blood pressure
Blood pressure will be measured in the right arm using an automated sphygmomanometer with the participant in a seated position after having rested quietly for 10-15 minutes. Participants will sit with feet flat on the floor and legs uncrossed and will be asked not to talk during the rest period or during the measurement. Systolic blood pressure will be defined as the average of three repeated measures.
Time frame: Baseline
Diastolic blood pressure
Blood pressure will be measured in the right arm using an automated sphygmomanometer with the participant in a seated position after having rested quietly for 10-15 minutes. Participants will sit with feet flat on the floor and legs uncrossed and will be asked not to talk during the rest period or during the measurement. Diastolic blood pressure will be defined as the average of three repeated measures.
Time frame: Baseline
C-reactive protein
C-reactive protein (CRP) will be determined using an automated immunoanalyzer.
Time frame: Baseline
Interleukin-6
Interleukin-6 (IL-6) will be assayed with high-sensitivity Quantikine®.
Time frame: Baseline
Soluble tumor necrosis factor receptor 1
Soluble tumor necrosis factor receptor 1 (sTNFR1) will be assayed with high-sensitivity Quantikine®.
Time frame: Baseline
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