Bariatric Surgery Improves Cognitive Function in Obese Women

Weight loss from bariatric surgery appears to reverse the increased cerebral metabolism and poor executive function associated with obesity, according to a study reported in the August 26 Journal of Clinical Endocrinology and Metabolism.

“Our findings reinforce the evidence that obesity has an influence on brain functioning,” said lead author Emerson Leonildo Marques, MD, PhD, Division of Endocrinology and Metabolism, University of São Paulo School of Medicine, São Paulo, Brazil. “We found a pattern of brain metabolism in obese patients that has been found in individuals with a genetic predisposition to Alzheimer's disease (carriers of the apolipoprotein E type 4 allele),” Dr. Marques said. “But obesity is a modifiable risk factor for dementia,” he said, adding that reducing obesity rates may reduce the incidence of Alzheimer’s disease.

The study involved 17 obese women (mean age, 40.5±10.1 years) who underwent Roux-en-Y gastric bypass surgery. Outcomes were compared with a group of 16 normal-weight women who were paired for age and education level.

Increased Cerebral Metabolic Activity Found After Bariatric Surgery
Women who underwent bariatric surgery showed a significant weight loss, but still had markedly higher BMI than the normal weight group (mean, 37.2 vs 22.3). At baseline, obese women had increased cerebral metabolic activity in select brain regions—namely the right posterior cingulate gyrus and the right posterior lobe of the cerebellum—compared with the control group. At 6-months after surgery, this increased cerebral metabolism was reversed with no between-group difference observed.

Further analysis showed that weight loss was significantly associated with improved cerebral metabolism and inflammatory parameters. While no between-group differences were found in performance on neuropsychological tests either before or after surgery, the obese group showed improved performance on the Trail Making Test—a measure of executive function—following surgery, compared with preoperative scores.  

Findings Suggest a Broader Application of Bariatric Surgery
“The brain is often neglected as an organ that is sensitive the devastating influence of adverse metabolic states such as severe obesity or diabetes,” commented Bernd Schultes, MD, Specialist in Internal Medicine and Endocrinology, eSwiss Medical and Surgical Center, St. Gallen, Switzerland. “Until now, [research has focused on the effects of obesity] on cardiovascular disease, kidneys, etc. However, most people will be even more afraid of getting dementia than of getting a myocardial infarction,” Dr. Schultes said.

“The ‘normalization’ of brain metabolism after gastric bypass surgery found in the present study suggests that 1) obesity is really causative for the found alterations and 2) that these alterations can be counteracted by weight loss and/or gastric bypass surgery,” Dr. Schultes said. “If [these findings are] confirmed in larger prospective clinical study, this would speak to a broader application of bariatric surgery in the obese population,” he added.

Dr. Schultes noted that many health care providers still believe that obesity can be overcome by increased willpower to live a healthier lifestyle and are unaware that bariatric surgery exerts strong effects on the brain, despite strong scientific evidence supporting this finding. “Hopefully, the results of present study will help to establish a boarded view on the relationship between metabolic diseases such as obesity and diabetes and behavioral aspects,” he said.

“Obesity is a severe disease that, apart from many organs, affects the brain,” Dr. Schultes said. “Obese people seem to be in a vicious circle were accumulation of fat mass and associated metabolic responses lead to changes in the central nervous system taking place at the homeostatic, emotional, and cognitive level that prevents weight loss and may even promote further weight gain. This said, we should take any measure, being it surgical or non-surgical, to help our obese patients to overcome this problem,” he said.

October 7, 2014


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