Pharmacological and Surgical Treatment of Obesity

The summary of Medication Outcome Studies reported in this site revealed no direct comparisons of weight loss medications (sibutramine, orlistat, topiramate and fluoxetine). Comparison of the results for each drug compared to placebo found no support for a hypothesis that one drug is more effect than the others. The difference among drugs in placebo-corrected mean weight loss at one year is only about 1 to 2 kg. None of the medications supported large weight loss. The mean placebo-corrected weight loss for all drugs was less than 5 kg at one year. The authors note, however, that even a moderate weight loss (5% of body weight) can significantly influence obesity-associated risk factors for poor health outcome.

The summary of Surgery Outcome studies supported data that surgical treatment results in greater weight loss than does medical treatment in obese individuals (BMI=340), resulting in 20 to 30 kg of weight loss, maintained up to eight years, that is accompanied by significant improvements in several comorbidities. For patients with a BMI between 35 and 40, the data strongly support the superiority of surgical therapy but cannot be considered conclusive in the absence of a study with a concurrent comparison group.

Further supporting the superiority of surgical therapy in patients with a BMI of 40 or greater is the observation that the weight loss reported in surgical studies is an order of magnitude greater than weight loss reported in pharmaceutical or diet studies of obesity (weight losses of 20-40 kg at one or two years in surgical studies versus 2 to 5 kg in pharmaceutical studies), although direct comparisons cannot be made across studies because patient populations are different. That is, the surgical studies enrolled only patients who are severely obese, whereas the average BMI in the medical weight loss studies was about 33. Additionally, many surgical studies report sustained weight loss (i.e., at 24 months or longer), whereas studies of medical weight loss therapies that report data beyond 12 months are rare, and those that do tend to report regain of most initial weight loss.

For a complete detail of the above, please see http://www.ahrq.gov/downloads/pub/evidence/pdf/obespharm/obespharm.pdf

Shekelle PG, Morton SC, Maglione MA, Suttorp M, Tu W, Li Z, Maggard M, Mojica WA, Shugarman L, Solomon V, Jungvig L, Newberry SJ, Mead D, Rhodes S. (2004). Pharmacological and Surgical Treatment of Obesity. Evidence Report/Technology Assessment No. 103. (Prepared by the Southern California–RAND Evidence-Based Practice Center, Santa Monica, CA, under contract Number 290-02-0003.) AHRQ Publication No. 04-E028-2. Rockville, MD: Agency for Healthcare Research and Quality. July 2004.

 
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