Age and Weight Loss After Bariatric Surgery: Cause or Consequence?

Abstract

In spite of its indisputable role in the treatment of obesity,bariatric surgery is not absent of cutbacks and complica-tions. Cumulative experience is allowing the discovery offactors associated with weight loss after bariatric surgery[1], which may allow the development of more selectiveand effective interventions. In this regard, both Contreraset al. [2] and Scozzari et al. [3] reports bring an importantcontribution, by clearly showing that patients’ age nega-tively associates with success in weight loss. In the dis-cussion of their results, the authors consider a range offacts possibly interfering with weight loss in people ofmore advanced age: from differences in energy require-ments to social and psychological aspects and, probably ofgreat importance, an impaired metabolic capacity and alower lipolytic activity.Results obtained by our group [4], in a sample of 163obese patients, showed that, in good agreement with theresults of Scozzari et al., younger patients (<50 years)achieved a greater weight loss after 12 months of follow-up (80 % excess weight loss (EWL) vs 70 % EWL; p=0.01). More interestingly, in the preoperative period and incomparison with older patients, younger (and most respon-sive) patients had significantly lower fasting glucose levels(93 vs 111 mg/dL; p<0.001) [4] and were less contaminat-ed with persistent organic pollutants (POPs) in visceraladipose tissue (168.9±13.7 ng/g of fat vs 311.0±32.7 ng/goffat,p<0.0001) [POPs data to be published]. Specifi-cally in our analysis, the effect of age disappeared afteradjustment for fasting blood glucose levels.As both higher fasting glucose [ 5] levels and higher levels ofPOPs [6] in adipose tissue will decr ease lipolysis, this seems tobe a most important mechanism behind the difficulty of olderpeople to respond to weight-los ing interventions. It would beinteresting to study the influence of age on weight loss by otherinterventions and to further evaluate the capacity of fastingglucose and POPs levels to predict weight loss independentlyof age.