Partial Reversibility of Hypothalamic Dysfunction and Changes in Brain Activity After Body Mass Reduction in Obese Subjects

  1. Licio A. Velloso1
  1. 1Laboratory of Cell Signaling, University of Campinas, Campinas, Brazil
  2. 2Department of Neurology, University of Campinas, Campinas, Brazil
  3. 3Faculty of Applied Sciences, University of Campinas, Campinas, Brazil
  4. 4Department of Anesthesiology, University of Campinas, Campinas, Brazil
  5. 5Department of Clinical Pathology, University of Campinas, Campinas, Brazil
  6. 6Department of Surgery, University of Campinas, Campinas, Brazil
  7. 7Laboratory of Investigation in Metabolism and Diabetes, University of Campinas, Campinas, Brazil
  1. Corresponding author: Licio A. Velloso, lavelloso.unicamp{at}


OBJECTIVE Inflammation and dysfunction of the hypothalamus are common features of experimental obesity. However, it is unknown whether obesity and massive loss of body mass can modify the immunologic status or the functional activity of the human brain. Therefore, the aim of this study was to determine the effect of body mass reduction on brain functionality.

RESEARCH DESIGN AND METHODS In humans, changes in hypothalamic activity after a meal or glucose intake can be detected by functional magnetic resonance imaging (fMRI). Distinct fMRI analytic methods have been developed to explore changes in the brain’s activity in several physiologic and pathologic conditions. We used two analytic methods of fMRI to explore the changes in the brain activity after body mass reduction.

RESULTS Obese patients present distinct functional activity patterns in selected brain regions compared with lean subjects. On massive loss of body mass, after bariatric surgery, increases in the cerebrospinal fluid (CSF) concentrations of interleukin (IL)-10 and IL-6 are accompanied by changes in fMRI patterns, particularly in the hypothalamus.

CONCLUSIONS Massive reduction of body mass promotes a partial reversal of hypothalamic dysfunction and increases anti-inflammatory activity in the CSF.

  • Received November 23, 2010.
  • Accepted March 13, 2011.

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