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Study rationale and protocol of the BARICO study: a longitudinal, prospective, observational study to evaluate the effects of weight loss on brain function and structure after bariatric surgery
  1. Debby Vreeken1,2,
  2. Maximilian Wiesmann2,
  3. Laura N Deden1,
  4. Ilse A C Arnoldussen2,
  5. Esther Aarts3,
  6. Roy P C Kessels3,4,5,
  7. Robert Kleemann6,
  8. Eric J Hazebroek1,
  9. Edo O Aarts1,
  10. Amanda J Kiliaan2
  1. 1 Department of Surgery, Rijnstate Hospital, Vitalys Clinic, Arnhem, The Netherlands
  2. 2 Department of Anatomy, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
  3. 3 Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
  4. 4 Department of Medical Psychology, Radboud University Medical Center, Nijmegen, The Netherlands
  5. 5 Vincent van Gogh Institute for Psychiatry, Venray, The Netherlands
  6. 6 Department of Metabolic Health Research, Netherlands Organization for Applied Scientific Research (TNO), Leiden, The Netherlands
  1. Correspondence to Dr Amanda J Kiliaan; amanda.kiliaan{at}


Introduction Weight loss after bariatric surgery (BS) is often associated with improved cognition and structural brain recovery. However, improved cognition after BS is not always exhibited by patients, in fact, in some cases there is even a decline in cognition. Long-term consequences of BS weight loss, in terms of obesity and related diseases, can be hard to determine due to studies having short follow-up periods and small sample sizes.

The aim of the BARICO study (BAriatric surgery Rijnstate and Radboudumc neuroImaging and Cognition in Obesity) is to determine the long-term effect of weight loss after BS on brain function and structure, using sensitive neuropsychological tests and (functional) MRI ((f)MRI). Secondary study endpoints are associated with changes in metabolic and inflammation status of adipose tissue, liver and gut, in relation to brain structure and function. Also, the possible correlation between weight loss, gut microbiota composition change and neuropsychological outcomes will be investigated.

Methods and analysis Data from 150 Dutch BS patients (ages between 35 and 55, men and women) will be collected at various time points between 2 months before and up to 10 years after surgery. Neuropsychological tests, questionnaires, blood, faeces and tissue samples will be collected before, during and after surgery to measure changes in cognition, microbiota, metabolic activity and inflammation over time. A subgroup of 75 participants will undergo (f)MRI in relation to executive functioning (determined by the Stroop task), grey and white matter volumes and cerebral blood flow. Regression analyses will be used to explore associations between weight loss and outcome measures.

Ethics and dissemination This study has been approved by the medical review ethics committee CMO Region Arnhem and Nijmegen (NL63493.091.17). Research findings will be published in peer-reviewed journals and at conferences.

Trial registration number NTR7288.

  • obesity
  • weight loss
  • bariatric surgery
  • neuroimaging
  • cognition

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  • EOA and AJK contributed equally.

  • Contributors EOA and AJK conceived and designed the study. DV wrote the article and developed the protocol together with EOA, AJK, EJH and RK. EJH, EOA and AJK are the principal investigators and DV is the main investigator. MW, LND, IACA, EA, RK and RPCK are coinvestigators in the participating centres. All authors critically reviewed the content and approved the final manuscript.

  • Funding This work is supported by a grant of the Rijnstate-Radboudumc promotion fund. The histopathological and biochemical analyses will be performed in collaboration with the Netherlands Organisation for Applied Scientific Research (TNO) Metabolic Health Research (Leiden, the Netherlands) with support from TNO’s Research programme Biomedical Health and the Shared Research Program GLoBAL, an initiative of Radboudumc, Rijnstate and TNO.

  • Competing interests Not required.

  • Patient consent Not required.

  • Ethics approval Medical review ethics committee CMO Region Arnhem and Nijmegen (NL63493.091.17).

  • Provenance and peer review Not commissioned; externally peer reviewed.

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