A Way to Predict the Success of Bariatric Surgery?

A presentation at the recent American College of Gastroenterology meeting aroused interest; it suggested that a blood test might be used to determine the likely success of one type of weight-loss surgery – gastric bypass – in causing the patient to lose weight postoperatively.  A study on 35 obese patients (average BMI 47.5) was done by Falls Church, Virginia, physicians.

Serum samples taken immediately before surgery (Roux-en-Y bypass) were tested for a variety of hormones: gastrointestinal peptides (obestatin, peptide YY, and glucagon-like peptide-1), markers of inflammation (IL6, IL7, IL8, G-CSF, CCL2, and MIP-1b), and ghrelin.  The patients were followed for a year after their surgery.    

Weight loss, which was faster during the first 3 months, led to a reduction in average BMI from 47.5 to 33.4.  The only hormone found to correlate with the rate of weight loss was obestatin – a peptide produced in the small intestine that’s supposed to play a role in satiety.  The strongest correlation between obestatin and the rate of weight loss was during the first 3 months, but it remained strong throughout the first year.

Experts peaking after the presentation said these results were fascinating, but need to be confirmed by further studies. One suggested it would be interesting to see what effect baseline obestatin had on the results of lap-band surgery. 

It would certainly be useful for bariatric surgeons to have a test that predicts the likely success of their efforts before the expensive surgery is undertaken.  Confirmation or refutation of these results is therefore an urgent matter.