Elsevier

Surgery for Obesity and Related Diseases

Volume 9, Issue 5, September–October 2013, Pages 765-770
Surgery for Obesity and Related Diseases

Original article
Cognitive function predicts 24-month weight loss success after bariatric surgery

https://doi.org/10.1016/j.soard.2013.04.011Get rights and content

Abstract

Background

Clinically significant cognitive impairment, particularly in attention/executive and memory function, is found in many patients undergoing bariatric surgery. These difficulties have previously been linked to decreased weight loss 12 months after surgery, but more protracted examination of this relationship has not yet been conducted. The present study prospectively examined the independent contribution of cognitive function to weight loss 24 months after bariatric surgery. Given the rapid rate of cognitive improvement observed after surgery, postoperative cognitive function (i.e., cognition 12 weeks after surgery, controlling for baseline cognition) was expected to predict lower body mass index (BMI) and higher percent total weight loss (%WL) at 24-month follow-up.

Methods

Data were collected by 3 sites of the Longitudinal Assessment of Bariatric Surgery (LABS) parent project. Fifty-seven individuals enrolled in the LABS project who were undergoing bariatric surgery completed cognitive evaluation at baseline, 12 weeks, and 24 months. BMI and %WL were calculated for 24-month postoperative follow-up.

Results

Better cognitive function 12 weeks after surgery predicted higher %WL and lower BMI at 24 months, and specific domains of attention/executive and memory function were robustly related to decreased BMI and greater %WL at 24 months.

Conclusions

Results show that cognitive performance shortly after bariatric surgery predicts greater long-term %WL and lower BMI 24 months after bariatric surgery. Further work is needed to clarify the degree to which this relationship is mediated by adherence to postoperative guidelines.

Section snippets

Trial design and participants

A total of 57 bariatric surgery patients were recruited into this multisite prospective study examining the neurocognitive effects of bariatric surgery. All participants were part of the Longitudinal Assessment of Bariatric Surgery (LABS) parent project and were recruited from 3 LABS sites [17]. Individuals participating in the parent project who were eligible for the present study were approached at the time of enrollment regarding this ancillary cognitive study. More than 80% of participants

Interventions and clinical follow-up

This study is registered with clinicaltrials.gov, and all procedures were approved by the appropriate Institutional Review Boards. All participants provided written informed consent before study involvement. Participants completed self-report measures of demographic and medical characteristics and a computerized cognitive test battery at baseline (within 30 days before surgery), 12 weeks (±5 days), and 24 months (±30 days) after surgery. Weight and height were measured in the research office

Outcomes

The present study examined whether cognitive function 12 weeks after bariatric surgery predicted %WL and BMI at 24-month follow-up. The Integneuro cognitive test battery demonstrates strong psychometric properties [19] and was chosen based on previous work from our laboratory showing its sensitivity to the cognitive difficulties manifested in obese persons [7]. This cognitive test battery consists of estimated premorbid intellectual abilities as well as performance in cognitive domains most

Data analyses

To facilitate clinical interpretation and maintain directionality within scales, all raw scores of neuropsychological measures assessing cognitive function were transformed to T-scores (a distribution with a mean of 50 and a standard deviation of 10) using existing normative data correcting for age, gender, and estimated premorbid intelligence. A global cognitive function composite score for baseline and 12-week postoperative time points was then created that consisted of the mean of the

Baseline, 12-week, and 24-month BMI and %WL

The average baseline BMI within the sample was 46.49 (SD = 5.22) kg/m2. There was a significant decrease in BMI from baseline to 12 weeks after surgery (F-statistic [F] [1,56] = 573.29; P<.001; mean 12-week BMI = 38.43 [SD = 4.81] kg/m2) and from 12 weeks to 24 months after surgery (F[1,56] = 119.59; P value<.001; mean 24-month BMI = 31.17 [SD = 6.46] kg/m2). Consistent with this pattern, there was a significant increase in %WL (F[1,56 = 120.77]; P<.001) from 12 weeks (Mean [M] = 17.30 [SD =

Discussion

The present study prospectively examined cognitive function as a predictor of weight loss after bariatric surgery. Patients who had undergone bariatric surgery demonstrated baseline cognitive impairment that improved 12 weeks after bariatric surgery. In addition, cognitive function at 12 weeks postoperatively was associated with lower BMI and significantly higher postoperative %WL at 24 months.

Finding that cognitive performance shortly after surgery predicts weight loss outcomes 2 years later

Conclusions

Results of the present study indicate that better cognitive test performance shortly after surgery predicts higher %WL and lower BMI 24 months after bariatric surgery. Further work is necessary to clarify the degree to which adherence to postoperative guidelines for diet, eating behavior, and physical activity contributes to the relationship between weight loss and cognitive function, because this approach may ultimately help identify those individuals in greatest need for intervention to

Disclosures

The authors have no commercial associations that might be a conflict of interest in relation to this article.

References (29)

  • J. Gunstad et al.

    Obesity is associated with memory deficits in young and middle-aged adults

    Eat Weight Disord

    (2006)
  • D.G. Feil et al.

    The role of cognitive impairment and caregiver support in diabetes management of older outpatients

    Int J Psychiatry Med

    (2009)
  • E. Vinvoles et al.

    Cognitive function and blood pressure control in hypertensives over 60 years of age: COGNIPRES study

    Curr Med Res Opin

    (2008)
  • T.R. Barclay et al.

    Age-associated predictors of medication adherence in HIV-positive adults: health beliefs, self-efficacy, and neurocognitive status

    Health Psychol

    (2007)
  • Cited by (56)

    • Cognitive Impairment is Common in a Veterans Affairs Population with Peripheral Arterial Disease

      2023, Annals of Vascular Surgery
      Citation Excerpt :

      Additionally, using the Vascular Quality Initiative, Mehaffey et al., found cognitive impairment was associated with increased inflation-adjusted costs, complications, and increased length of stay at the preoperative, postoperative, and intensive care levels.25 Cognitive impairment may undermine successful management of PAD by not only impacting a patient’s ability to adhere to best medical and exercise therapy, but also posing challenges to informed consent.26-30 Pertaining to medication adherence, a systematic review of cognitive impairment’s impact on medication adherence found adherence to range from 17%-42% among those with dementia.27

    View all citing articles on Scopus

    Data collection supported by DK075119. Manuscript supported in part by HL089311. The authors acknowledge the use of LABS data as the sole contribution of the LABS consortium.

    View full text