Obesity, MorbidNCT05215886
Cognitive Impairment, Obesity, and the Effects of Bariatric Surgery
An observational study of Obesity, Morbid and Bariatric Surgery Candidate, run by University of California, Davis at 1 site in United States.
Trial summary
Study is designed to screen psychological cognitive baseline and retention/improvement after weight loss surgery. Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Obesity, Morbid, Bariatric Surgery Candidate
- What is being tested?
- Surgery
- Type of treatment
- Lifestyle or therapy programme
- How many people
- 9,500 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Jan 2022to 31 Dec 2028
- Phase
- Observational
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Subjects seeking weight loss surgery or with a history of weight loss surgery at University of California Davis Medical Center 18 years of age or older
Who may be able to join
- Cognitive impairment/decline, memory impairment/loss, or Alzheimer's disease or dementia and bariatric surgery • Cognitive impairment/decline, memory impairment/loss, or Alzheimer's disease or dementia and obesity, and no bariatric surgery history
Who cannot join
- Patients without a history of memory impairment/loss, bariatric surgery, or obesity
- Patients outside of University of California Davis Health System
- Patients unable to provide consent
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site
University of California Davis Medical Center
Sacramento, California, 95817
About this study
Study is designed to screen psychological cognitive baseline and retention/improvement after weight loss surgery.
Read the detailed description
Patients with morbid obesity have shown to be at increased risk for memory loss and cognitive decline. Obesity and high-fat diets have been associated with deficits in learning, memory, and executive functioning. Bariatric surgery results in significant weight loss for patients and helps resolve obesity-related comorbidities such as diabetes and high blood pressure. Interestingly, bariatric surgery has shown promise in improving some aspects of cognitive function and improved memory. (3-1) Obesity affects brain structure, more specifically the grey and white matter, likely in part by reducing oxygen flow to the various regions in the brain. Studies have shown a correlation between BMI and cerebral blood flow velocity (CBFV), where higher BMI is associated with lower CBFV. Although it is not clear how exactly obesity plays a role in the brain's structural and functional changes, observations revealed compromised grey and white matter integrity, its fiber connectivity or cortical atrophy and metabolic alterations. (2)
Few studies exist on the impact of bariatric surgery on cognition. Some studies have shown that patients with obesity who underwent bariatric surgery had memory and cognitive improvement compared to those who had not undergone surgery. (4) Thus, the investigators hope to add to our understanding of how bariatric surgery can improve cognitive decline and to potentially offer surgery to more patients with baseline cognitive impairment and to improve cognitive function overall for patients with obesity. More longitudinal studies need to be done to connect bariatric surgery effects with cognitive decline, specifically memory.
- Conditions
- Obesity, Morbid, Bariatric Surgery Candidate
- Being tested
- Surgery
- Keywords
- Obesity, Bariatric Surgery, Cognitive Screening
- Medical subject headings
- Obesity, Morbid, Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
SurgeryBehavioural
Study subjects scheduled for or have already completed weight loss surgery and have already completed psychological screening as part of their pre-surgery work up
| Study group | Role | What they receive |
|---|---|---|
| Surgery | Patients scheduled for or have already completed Weight Loss Surgery at UC Davis Medical Center Receives: Behavioral: Surgery |
What is being measured
The primary outcome is the main question the study is designed to answer.
California Verbal Learning Test-3rd Edition (CVLT-3)
Measures episodic verbal learning including Verbal Learning, immediate memory, and delayed memory
Measured: Pre-operatively
California Verbal Learning Test-3rd Edition (CVLT-3)
Measures episodic verbal learning including Verbal Learning, immediate memory, and delayed memory
Measured: 12 Months after index screening/date of surgery
Secondary outcomes (9)
Brief Visuospatial Memory Test
Measures visuospatial learning and memory, including visual learning, immediate memory, and delayed memory.
Measured: Pre-operatively and 12 months after index screening/date of surgery
Brief Visuospatial Memory Test
Measures visuospatial learning and memory, including visual learning, immediate memory, and delayed memory.
Measured: Pre-operatively
Trial Making Test, A & B
Measures visual spatial attention, motor speed and cognitive flexibility
Measured: 12 months after index screening/date of surgery
WAIS-IV Digit Span Forward & Backward
Measures auditory Attention (Forward), and Auditory attention and working memory (Backward)
Measured: Pre-Operatively
WAIS-IV Digit Span Forward & Backward
Measures auditory Attention (Forward), and Auditory attention and working memory (Backward)
Measured: 12 months after Index screening/date of surgery
Verbal Fluency, Phonemic & Semantic
Measures verbal fluency by a word generation task based on letter \& category (executive functioning)
Measured: Pre-operatively
Verbal Fluency, Phonemic & Semantic
Measures verbal fluency by a word generation task based on letter \& category (executive functioning)
Measured: 12 months after index screening/date of surgery
Stroop Color and Word Test; Word, Color & Word-Color
Measures reading speed (word), naming speed (processing) and selective attention and inhibition (attention/executive functioning)
Measured: Pre-Operatively
Stroop Color and Word Test; Word, Color & Word-Color
Measures reading speed (word), naming speed (processing) and selective attention and inhibition (attention/executive functioning)
Measured: 12 months after index screening/date of surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 Jan 2022
- Study start1 Jan 2022
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Dec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for Obesity, MorbidStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case only
- Time perspective
- Cross-sectional
- Enrolment
- 9,500 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of California, Davis
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Victoria Lyo, MD, Principal investigator, University of California, Davis
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05215886
- Sponsor's protocol ID
- 1812245
- Status last verified
- Dec 2025
- First submitted
- 18 Jan 2022
- Last updated
- 5 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: No plan in place (yet) for data sharing
Publications
Alosco ML, Spitznagel MB, Strain G, Devlin M, Cohen R, Paul R, Crosby RD, Mitchell JE, Gunstad J. Improved memory function two years after bariatric surgery. Obesity (Silver Spring). 2014 Jan;22(1):32-8. doi: 10.1002/oby.20494. Epub 2013 Oct 15.
PubMed 23625587Nota MHC, Vreeken D, Wiesmann M, Aarts EO, Hazebroek EJ, Kiliaan AJ. Obesity affects brain structure and function- rescue by bariatric surgery? Neurosci Biobehav Rev. 2020 Jan;108:646-657. doi: 10.1016/j.neubiorev.2019.11.025. Epub 2019 Nov 30.
PubMed 31794778Miller AA, Spencer SJ. Obesity and neuroinflammation: a pathway to cognitive impairment. Brain Behav Immun. 2014 Nov;42:10-21. doi: 10.1016/j.bbi.2014.04.001. Epub 2014 Apr 12.
PubMed 24727365Stanek KM, Gunstad J. Can bariatric surgery reduce risk of Alzheimer's disease? Prog Neuropsychopharmacol Biol Psychiatry. 2013 Dec 2;47:135-9. doi: 10.1016/j.pnpbp.2012.06.021. Epub 2012 Jul 4.
PubMed 22771689