Examination of Cognitive Function in Obesity and Following Weight Loss

Withdrawn

• Conditions: Bariatric Surgery Candidate; Obesity; Weight Loss
• Interventions: Other: Medical Weight Loss Program; Procedure: Bariatric Surgery

• Registration Number: NCT02994186
• Lead Sponsor: Vanderbilt University Medical Center

Brief Summary

Bariatric surgery is the most effective, long-term treatment for morbid obesity, and consistent with previous findings, individuals who lose significant weight after surgery also have improved cognition or "brain function". The mechanisms behind these cognitive improvements are currently unknown, but are the focus of much research effort. The goal of this pilot study is to thoroughly describe these changes in surgical versus medical weight loss patients over time in a repeated measures fashion.

Detailed Description

Recent studies have demonstrated that obesity is associated with decreased cognitive function and, interestingly, weight loss is associated with improved cognitive function. Bariatric surgery is the most effective, long-term treatment for morbid obesity, and consistent with these previous findings, individuals who lose significant weight after surgery appear to have improved cognition. Previous results have only reported the appearance of cognitive improvements starting at three months postoperatively, thus, the main focus of this study is to discover whether cognitive function improvements are seen as early as one month after bariatric surgery. An acceleration in the onset of cognitive function changes could provide insight towards the ambiguous underlying neural mechanisms. The benefits of bariatric surgery extend beyond reversible cognitive deficits. Many of the medical comorbid conditions that these patients have before surgery (e.g. high blood pressure, high cholesterol, diabetes) typically resolve prior to any significant weight loss. The mechanisms for these weight-independent improvements are also undetermined. A secondary focus of this study is to determine whether or not cognitive function following bariatric surgery also improves prior to significant weight loss. To test whether cognitive function changes following bariatric surgery, two cohorts of surgical patients will be recruited as well as another group of patients undergoing medical weight loss treatment. The goal of this pilot study is to reproduce and expand upon previous findings that demonstrate cognitive improvements following bariatric surgery.

Study Timeline

• Study First Submitted: 2016-12-12
• Study First Submitted QC: 2016-12-14
• Study First Posted: 2016-12-15
• Study Start: 2018-07-01
• Status Verified: 2018-09
• Last Update Submitted: 2018-09-25
• Last Update Posted: 2018-09-27
• Primary Completion: 2019-12
• Study Completion: 2020-07

Recruitment & Eligibility

• Status: WITHDRAWN
• Sex: All
• Target Recruitment: Not specified

Inclusion Criteria

• English speaking
• Within the age rage of 18-70 years
• Able to give informed consent

Exclusion Criteria

• Neurological disorder or previous injury (e.g. stoke, dementia, seizures, traumatic brain injury)
• History of any moderate to severe head injury (i.e. >5 minutes of loss of consciousness)
• History of severe psychiatric illness requiring current pharmacologic therapy(e.g. schizophrenia, bipolar disorder, personality disorders)
• History of illicit drug or alcohol abuse
• Known diagnosis of learning or developmental disability
• Impaired sensory function
• Any prior suicide attempt
• Revisional bariatric surgery
• Current or former tobacco user / smoker
• Currently pregnant

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Medical Weight Loss	Medical Weight Loss Program	Patients in this group are those who are being enrolled in a supervised medical weight loss program.
Surgical Weight Loss	Bariatric Surgery	Patients in this group are those that will be undergoing bariatric surgery (either Roux-en-Y gastric bypass or vertical sleeve gastrectomy).

Primary Outcome Measures

Name	Time	Method
Cognitive Function Score - Surgical Group Comparison	Repeated Measures Up to 6 Months	Within group and between group longitudinal measurements will be made using longitudinal regression methods. Baseline as well as 1, 3 and 6 month measurements will be captured either from the time of bariatric surgery or initiation of a supervised medical weight loss program. The bariatric operation will be included (Roux-en-Y gastric bypass vs. Vertical Sleeve Gastrectomy) as a variable in the regression model for between and within subjects comparisons in the bariatric surgery group.
Cognitive Function Score	Repeated Measures Up to 6 Months	Within group and between group longitudinal measurements will be made using longitudinal regression methods. Baseline as well as 1, 3 and 6 month measurements will be captured either from the time of bariatric surgery or initiation of a supervised medical weight loss program.

Secondary Outcome Measures

Name	Time	Method
Cognitive Function Score - Crossover Patients	Repeated Measures Up to 6 Months	There will be a group of patients that will crossover at 6 months from the medical weight loss group to the surgical weight loss group. The cognitive function score in these patients will be compared between treatment groups, as they will effectively be represented in each group.