Bariatric Surgery Associated With Improved Cognition and General Brain Health

Bariatric surgery-induced weight loss is associated with sustained health benefits after 2 years, including improved global cognition, blood vessel efficiency, brain structure, and general health, according to study results published in JAMA Network Open.

Researchers conducted a cohort study to determine the long-term impacts of weight loss via bariatric surgery on cognition, as well as brain structure and perfusion. Patients aged 35 to 55 who had severe obesity (body mass index [BMI] >40, or BMI >35 with comorbidities) and were eligible for Roux-en-Y gastric bypass were included in this study. The researchers collected data from the Bariatric Surgery Rijnstate and Radboudumc Neuroimaging and Cognition in Obesity study between September 2018 and December 2020, with a follow-up period extending through March 2023.

Primary outcomes of interest included body weight, BMI, waist circumference, blood pressure, medication use, cognitive performance, brain volumes, and cortical thickness. Secondary outcomes of interest included depressive symptoms and physical activity. Cognition was assessed using a series of neuropsychological tests at baseline and at 6 and 24 months post-bariatric surgery. MRI scans were also conducted at baseline and 24 months post-bariatric surgery, while blood samples and anthropometric data were collected at all timepoints. Changes in outcomes over time were evaluated using analyses of variance and continuous and categorial data were assessed using the Cochran, Friedman, and Wilcoxon signed rank tests.

Overall, 133 patients (mean age, 46.8; women, 84.2%) were included in the study. Between baseline and 24 months post-bariatric surgery, mean body weight (122.46 kg vs 80.45 kg), mean BMI (41.87 vs 27.44), mean waist circumference (125.14 cm vs 93.67 cm), and blood pressure all lowered.

Improvements in several cognitive domains at 6 and 24 months after bariatric surgery were observed:

15 (11.3%) patients had improved working memory,

42 (31.6%) had improved episodic memory, 32 (24.1%) had improved verbal fluency, 51 (40.2%) had improved attention, and

52 (42.9%) had improved global cognition by at least 20%.

Compared with baseline, at 24 months, the use of antihypertensives had also improved (48 [36.1%] patients vs 22 [16.7%] patients, respectively).

Following bariatric surgery, gray matter volume, cortical thickness, and cerebral blood flow were significantly lower at 2 years. No volumetric changes, however, were observed in the hippocampus, nucleus accumbens, frontal cortex, or white matter.

At 6 months after bariatric surgery, high-sensitivity C-reactive protein (CRP), leptin, serum amyloid A, tumor necrosis factor-α, interleukin (IL) 1ß, IL-6, and plasminogen activator inhibitor-1 levels were all significantly lower. At 24 months post-surgery, CRP levels declined even further (baseline, 4.77 μg/mL vs 24 months, 0.80 μg/mL; P <.001).

Compared with baseline, at 24 months post-bariatric surgery, median cumulative Beck Depression Inventory score also improved (9.0 vs 3.0, respectively).

Baecke Questionnaire scores, an indication of physical activity levels, were greater at 6 months after bariatric surgery vs baseline (mean, 8.19 vs 7.64, respectively; P <.001), and remained stable at 24 months following surgery.

Study limitations included the lack of a control group, imbalanced sex distribution in sample, and the exclusion of certain parameters, such as cortical surface and curvature.

“These findings suggest that bariatric surgery was associated with long-term health benefits, including improvements in comorbidities, inflammation, and cognition; moreover, higher cortical thickness and lower spatial coefficient of variation were found in the temporal lobe 2 years after surgery,” the researchers concluded.

Disclosure: This study was supported by the Rijnstate-Radboudumc Promotion Fund. Multiple study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of the authors’ disclosures.