Factors Associated With Cognitive Improvement After Bariatric Surgery Among Patients With Severe Obesity in the Netherlands

Abstract

ImportanceBariatric surgery–induced weight loss is often associated with improved cognitive function. However, improvement in cognitive function is not always exhibited by all patients, and the mechanisms behind cognitive improvement remain unknown.ObjectiveTo investigate the association of changes in adipokines, inflammatory factors, mood, and physical activity with alterations in cognitive function after bariatric surgery among patients with severe obesity.Design, Setting, and ParticipantsThis cohort study included 156 patients with severe obesity (body mass index [calculated as weight in kilograms divided by height in meters squared], >35) eligible for Roux-en-Y gastric bypass, aged between 35 and 55 years, who were enrolled in the BARICO (Bariatric Surgery Rijnstate and Radboudumc Neuroimaging and Cognition in Obesity) study between September 1, 2018, and December 31, 2020. Follow-up was completed July 31, 2021; 146 participants completed the 6-month follow-up and were included in the analysis.InterventionRoux-en-Y gastric bypass.Main Outcomes and MeasuresOverall cognitive performance (based on a 20% change index of the compound z score), inflammatory factors (eg, C-reactive protein and interleukin 6 levels), adipokines (eg, leptin and adiponectin levels), mood (assessed via the Beck Depression Inventory), and physical activity (assessed with the Baecke questionnaire).ResultsA total of 146 patients (mean [SD] age, 46.1 [5.7] years; 124 women [84.9%]) completed the 6-month follow-up and were included. After bariatric surgery, all plasma levels of inflammatory markers, including C-reactive protein (median change, −0.32 mg/dL [IQR, –0.57 to –0.16 mg/dL]; P < .001) and leptin (median change, −51.5 pg/mL [IQR, –68.0 to –38.4 pg/mL]; P < .001), were lower, whereas adiponectin levels were higher (median change, 0.15 μg/mL [IQR, –0.20 to 0.62 µg/mL]; P < .001), depressive symptoms were (partly) resolved (median change in Beck Depression Inventory score, −3 [IQR, –6 to 0]; P < .001), and physical activity level was higher (mean [SD] change in Baecke score, 0.7 [1.1]; P < .001). Cognitive improvement was observed in 43.8% (57 of 130) of the participants overall. This group had lower C-reactive protein (0.11 vs 0.24 mg/dL; P = .04) and leptin levels (11.8 vs 14.5 pg/mL; P = .04) and fewer depressive symptoms at 6 months (4 vs 5; P = .045) compared with the group of participants who did not show cognitive improvement.Conclusions and RelevanceThis study suggests that lower C-reactive protein and leptin levels, as well as fewer depressive symptoms, might partly explain the mechanisms behind cognitive improvement after bariatric surgery.

Long-Term Brain Structure and Cognition Following Bariatric Surgery

“…These findings suggest that cognitive improvements begin shorty after BS and are long lasting. Various factors may be involved, including remission of comorbidities, higher physical activity, lower depressive symptoms, and lower inflammatory factors after BS . Additionally, stabilization of volume, CBF, and sCOV in brain regions, together with larger cortical thickness and higher vascular efficiency in the temporal cortex, might be involved.…”

“…Bariatric surgery (BS) leads to rapid and sustainable weight loss and improves comorbidities . Moreover, BS-induced weight loss has been reported to be associated with improved brain function and structure . However, results are contradictory, underlying mechanisms remain largely unknown, and it is uncertain whether outcomes are long-lasting.…”

“… 18 Moreover, BS-induced weight loss has been reported to be associated with improved brain function and structure. 19 , 20 , 21 , 22 However, results are contradictory, underlying mechanisms remain largely unknown, and it is uncertain whether outcomes are long-lasting. Imbalance of adipokines and proinflammatory cytokines may be involved, as they impair CBF and therewith cause neurodegeneration, 23 which may be reversible after BS.…”

Development of a novel non-invasive biomarker panel for hepatic fibrosis in MASLD

“…Of the 128 patients, 68 were enrolled in the Amsterdam MASLD-MASH cohort (ANCHOR) study 46 . Twenty-two participants were randomly selected from the group of patients with fibrosis stage F0 or F1 in the BARICO (Bariatric Surgery Rijnstate and Radboudumc Neuroimaging and Cognition in Obesity) study 47 to enrich the testing cohort with patients without fibrosis. The remaining 38 patients underwent liver biopsies as part of their clinical evaluation and staging process at the Leiden University Medical Center.…”

Bariatric Surgery and Gut-Brain-Axis Driven Alterations in Cognition and Inflammation

“…However, adipose dysfunction, increased inflammation and mood disorders are suggested to play a role. [8][9][10] Increasing evidence shows that obesity driven cognitive impairment may be reversible by weight loss, 11 with the largest improvements in working memory 12 and executive function. 13,14 However, substantial long-term weight loss is often hard to achieve with dietary interventions.…”