Diet and Exercise Plus Metformin to Treat Frailty in Obese Seniors (DEMFOS)

December 31, 2025 updated by: VA Office of Research and Development

Lifestyle Intervention Plus Metformin to Treat Frailty in Older Veterans With Obesity

The continuing increase in prevalence of obesity in older adults including many older Veterans has become a major health concern. The clinical trial will test the central hypothesis that a multicomponent intervention consisting of lifestyle therapy (diet-induced weight loss and exercise training) plus metformin will be the most effective strategy for reversing sarcopenic obesity and frailty in older Veterans with obesity.

Study Overview

Detailed Description

The growing prevalence of obesity in older adults including many older Veterans, has become a major concern in the US already strained health care system in general and in the VA in particular. In older adults, obesity exacerbates the age-related decline in physical function resulting in frailty, decrease in quality of life, loss of independence, and increase in nursing home admissions. The investigators' group demonstrated that weight loss from lifestyle therapy improves physical function and ameliorates frailty but the improvement was modest at best and most obese older adults remained frail. More importantly, there are concerns that the weight-loss induced loss of muscle and bone mass could worsen underlying age-related sarcopenia and osteopenia in the subset of frail obese elderly. Metformin, a biguanide, is a widely available drug used as first line treatment of type 2 diabetes. Animal studies suggest that metformin improves health span and increases lifespan, hence may represent a novel intervention for frailty. Because metformin reduces cellular senescence and senescence-associated phenotype (SASP), it is believed to retard accelerated aging most especially in older adults with obesity. The objective is to conduct a head-head comparative efficacy, placebo controlled, randomized controlled trial to test the hypothesis that lifestyle therapy + metformin for six months will be more effective than lifestyle therapy alone or metformin alone in improving physical function and preventing the weight loss-induced reduction in muscle and bone mass in obese (BMI > 30 kg/m2) older (age 65 - 85 years) Veterans with physical frailty.

Study Type

Interventional

Enrollment (Actual)

114

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Texas
      • Houston, Texas, United States, 77030-4211
        • Michael E. DeBakey VA Medical Center, Houston, TX

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

65 years to 85 years (Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Age 65 - 85 years
  • BMI = or > 30 kg/m2
  • Mild to moderate frailty (score of 18 to 31 in the modified Physical Performance Test)
  • Stable body weight (plus/minus 2 kg) during the past 6 months
  • Sedentary (regular exercise <1 h/wk or <2 x/wk for the last 6 months)
  • Willing to provide informed consent

Exclusion Criteria:

  • Any major chronic diseases, or any condition that would interfere with exercise or dietary restriction, or use of metformin, in which exercise, dietary restrictions, or metformin are contraindicated, or that would interfere with interpretation of results
  • Cardiopulmonary disease (e.g. recent MI, unstable angina, stroke) or unstable disease (e.g., NYHA Class III or IV congestive heart failure, severe pulmonary disease requiring steroid pills or the use of supplemental oxygen) that would contraindicate exercise or dietary restriction
  • Severe orthopedic (e.g. awaiting joint replacement) and/or neuromuscular (e.g. multiple sclerosis, active rheumatoid arthritis) disease or impairments that would contraindicate participation in exercise
  • Renal impairment as defined by an estimated glomerular filtration rate (eGFR of less than 30 mL/min/1.73 m2) in which metformin is contraindicated
  • Other significant co-morbid disease that would impair ability to participate in the exercise intervention (e.g. severe psychiatric disorder [e.g. bipolar, schizophrenia], excess alcohol use [>14 drinks per week])
  • Severe visual or hearing impairments that would interfere with following directions
  • Significant cognitive impairment, defined as a known diagnosis of dementia or positive screening test for dementia using the Mini-Mental State Exam (i.e. MMSE score <24)69
  • Uncontrolled hypertension (BP>160/90 mm Hg)
  • History of malignancy during the past 5 years (except non-melanoma skin cancers)
  • Current use of bone acting drugs (e.g. use of estrogen, or androgen containing compound,raloxifene, calcitonin, parathyroid hormone during the past year or bisphosphonates during the last two years)
  • Osteoporosis (T-score -2.5 and below on hip or spine scan) or history of fragility fractures
  • Known history of diabetes mellitus or any of the following:
  • Fasting blood glucose of 126 mg/dl, or HbA1c of 6.5% or >
  • Terminal illness with life expectancy less than 12 months, as determined by a physician
  • Use of any drugs or natural products designed to induce weight loss within past three months
  • History of excessive alcohol consumption (e.g. 8 or more drinks a week for women and 15 or more drinks a week for men)
  • Positive exercise stress test for ischemia or any indication for early termination of exercise stress testing
  • Taking metformin or any other glucose lowering drug
  • Lives outside of the study site or is planning to move out of the area in the next 2 years

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Lifestyle Therapy plus Placebo
Diet-induced weight loss and Exercise Training plus Placebo
Weight management program, in which participants are prescribed a balanced diet that provides and energy deficit of 500 to 750 kcal per day to induced ~10% weight loss plus Supervised combined aerobic and resistance exercise training three times weekly
Other Names:
  • Diet-induced weight loss and exercise training
Given orally starting at 500 mg (one tablet) taken orally once a day with meals. After a week, the dose of placebo will be increased to 1000 mg (two tablets) daily. After another week, the dose of placebo will be increased to 1500 mg (three tablets) daily.
Experimental: Lifestyle Therapy plus Metformin
Diet-induced weight loss and Exercise Training plus Metformin 1500 mg daily
Weight management program, in which participants are prescribed a balanced diet that provides and energy deficit of 500 to 750 kcal per day to induced ~10% weight loss plus Supervised combined aerobic and resistance exercise training three times weekly
Other Names:
  • Diet-induced weight loss and exercise training
Given orally starting at 500 mg (one tablet) taken orally once a day with meals. After a week, the dose of metformin will be increased to 1000 mg (two tablets) daily. After another week, the dose of metformin will be increased to 1500 mg (three tablets) daily.
Active Comparator: Healthy lifestyle plus Metformin
Healthy lifestyle and Metformin 1500 mg daily
Given orally starting at 500 mg (one tablet) taken orally once a day with meals. After a week, the dose of metformin will be increased to 1000 mg (two tablets) daily. After another week, the dose of metformin will be increased to 1500 mg (three tablets) daily.
Group educational sessions that focus on healthy diet, exercise, and social support once a month

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in the modified Physical Performance Test (PPT)
Time Frame: 6 months
The Physical Performance Test includes seven standardized tasks (walking 15.2 m [50 ft], putting on and removing a coat, picking up a penny, standing up from a chair, lifting a book, climbing one flight of stairs, and performing a progressive Romberg test) plus two additional tasks (going up and down four flights of stairs and making a 360-degree turn). The score for each task ranges from 0 to 4, with higher scores indicating better physical performance; a perfect score would be 36.
6 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in muscle strength
Time Frame: 6 months
Assessed by biodex dynamometer and1-repetition maximum
6 months
Change in peak aerobic power
Time Frame: 6 months
Assessed by indirect calorimetry during a graded exercise test
6 months
Change in lean body mass
Time Frame: 6 months
Assessed by dual-energy x-ray absorptiometry (DXA)
6 months
Chang in body fat
Time Frame: 6 months
Assessed by DXA
6 months
Change in thigh muscle
Time Frame: 6 months
Assessed by magnetic resonance imaging (MRI)
6 months
Change in bone microarchitecture
Time Frame: 6 months
Assessed by high-resolution peripheral quantitative computed tomograph (HR-pQCT)
6 months
Change in bone strength
Time Frame: 6 months
Assessed by finite-element analyses
6 months
Change in hip, lumbar spine, and wrist bone mineral density (BMD)
Time Frame: 6 months
Assessed by DXA
6 months
Change in serum C-telopeptide
Time Frame: 6 months
Assessed by immunoassay
6 months
Change in mood
Time Frame: 6 months
Assessed by geriatric depression scale (score range: 0 to 30, where lower scores indicating better mood)
6 months
Change in serum procollagen type 1 N propeptide
Time Frame: 6 months
Assessed by radioimmunoassay
6 months
Change in serum 25-OH vitamin D
Time Frame: 6 months
Assessed by immunoassay
6 months
Change in serum parathyroid hormone
Time Frame: 6 months
Assessed by immunoassay
6 months
Change in high-sensitivity c-reactive protein
Time Frame: 6 months
Assessed by immunoassay
6 months
Change in Medical Outcomes 36-Item short form Health survey (SF-36)
Time Frame: 6 months
Assessed by Physical component summary and mental component summary score (score range 0 to 100, with higher scores indicating better health status)
6 months
Change in Impact of Weight on Quality of Life_Lite (IWQOL-lite) score
Time Frame: 6 months
Assessed by IWQO-liteL questionnaire
6 months
Change in serum adiponectin
Time Frame: 6 months
Assessed by ELISA
6 months
Change in serum leptin
Time Frame: 6 months
Assessed by ELISA
6 months
Change in fasting serum insulin
Time Frame: 6 months
Assessed by immunoassay
6 months
Change in fasting serum glucose
Time Frame: 6 months
Assessed by glucose oxidase method
6 months
Change in serum lipids
Time Frame: 6 months
Assessed by automated enzymatic/colorimetric assays
6 months
Change in insulin growth factor 1
Time Frame: 6 months
Assessed by immunoassay
6 months
Change in Cognitive composite scores
Time Frame: 6 months

Using cognitive toolbox which yields the following summary scores: Cognitive Function

Composite Score, Fluid Cognition Composite Score, and Crystallized Cognition Composite Score (score range: -3 to +3 for each with higher scores indicating better cognitive status

6 months
Change in telomere length
Time Frame: 6 months
Assessed by Q-PCR
6 months
Change in p16 and other markers of cell arrest
Time Frame: 6 months
Assessed by immunohistochemistry
6 months
Change in protein expression of senescence associated secretory phenotype
Time Frame: 6 months
Assessed by elisa or western blotting
6 months
Change in gait speed
Time Frame: 6 months
Assessed by time need to walk a certain distance
6 months
Change in blood pressure
Time Frame: 6 months
Assessed by sphygmomanometry
6 months

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
change in Senescent Associated Secretory Phenotype (SASP)
Time Frame: 6 months
Measured by immunoassay-based platform; results will be expressed as composite factor score
6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Dennis T Villareal, MD, Michael E. DeBakey VA Medical Center, Houston, TX

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 14, 2021

Primary Completion (Actual)

July 31, 2025

Study Completion (Actual)

July 31, 2025

Study Registration Dates

First Submitted

January 2, 2020

First Submitted That Met QC Criteria

January 6, 2020

First Posted (Actual)

January 9, 2020

Study Record Updates

Last Update Posted (Actual)

January 5, 2026

Last Update Submitted That Met QC Criteria

December 31, 2025

Last Verified

December 1, 2025

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Publications from this research will be made available to the public through the National Library of Medicine PubMed Central website within one year after the date of publication (guidance is provided on the ORD website).

MEDVAMC will not provide unrestricted, open public access to large scale health related datasets because of re-identification concerns and the obligation to protect Veterans' private information. However, controlled public access will be provided to the greatest extent possible under specific DUAs or other written agreements, and open access will be provided to the final datasets underlying peer-reviewed publications (aggregated data that can be released with privacy and confidentiality risks).

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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