Spotlight on obesity treatments

Recent studies assessed the safety and efficacy of bariatric surgery and a medication to treat obesity, while the U.S. Preventive Services Task Force updated its 2012 recommendations on behavioral interventions for adults with obesity.

Surgical, pharmacological, and behavioral treatments for patients with obesity were the subject of two recent studies and a new U.S. Preventive Services Task Force (USPSTF) recommendation statement.

In one systematic review, researchers assessed 16 studies published after 2000 to compare the effectiveness and safety of bariatric surgery procedures in the Medicare-eligible population. The nonrandomized, comparative studies assessed the association between bariatric procedures and weight loss, postoperative complications, mortality, medication use, and metabolic, cardiovascular, respiratory, orthopedic, and renal outcomes.

Results were published online on Sept. 5 by JAMA Surgery.

Compared with no surgery or conventional weight-loss treatment, bariatric surgery was associated with greater weight loss. Roux-en-Y gastric bypass was associated with greater weight loss compared to sleeve gastrectomy and adjustable gastric banding (percent excess weight loss, 23.8% [95% CI, 16.2% to 31.4%] at the longest follow-up of four years), although the procedures had similar associations with most non-weight loss outcomes. Serious complications were more common after Roux-en-Y gastric bypass than after sleeve gastrectomy.

Mortality after 30 days was also lower in patients who had bariatric surgery than in those who did not (hazard ratio, 0.50 [95% CI, 0.31 to 0.79] in the study with the longest follow-up of 5.9 years). However, in one study, 30-day mortality was higher in patients who had surgery than in nonsurgically treated controls (1.55% vs. 0.53%; P<0.001).

In the largest study comparison, bariatric surgery was associated with lower risk of cardiovascular disease (hazard ratio, 0.59; 95% CI, 0.44 to 0.79) and with improvements in respiratory, musculoskeletal, metabolic, and renal outcomes. For both weight loss and non-weight loss outcomes, the strength of the evidence was low to moderate for causal effects of bariatric surgery in the Medicare-eligible population, the review authors noted.

Lorcaserin, a selective serotonin 2C receptor agonist that modulates appetite, may also facilitate weight loss without a higher rate of major cardiovascular events compared to placebo, according to an industry-funded study.

Researchers randomized 12,000 patients with overweight or obesity who had atherosclerotic cardiovascular disease or multiple cardiovascular risk factors to receive either lorcaserin (10 mg twice daily) or placebo. The primary safety outcome (a composite of cardiovascular death, myocardial infarction, or stroke) was assessed for noninferiority at an interim analysis. Once noninferiority was achieved, the primary cardiovascular efficacy outcome (a composite of major cardiovascular events plus heart failure, hospitalization for unstable angina, or coronary revascularization—the so-called extended major cardiovascular events) was assessed for superiority at the end of the trial.

Results were published online on Aug. 26 by the New England Journal of Medicine.

At one year, weight loss of at least 5% body weight had occurred in 1,986 of 5,135 (38.7%) patients in the lorcaserin group and in 883 of 5,083 (17.4%) of those in the placebo group (odds ratio, 3.01 [95% CI, 2.74 to 3.30]; P<0.001). During a median follow-up of 3.3 years, the rate of the primary safety outcome was 2.0% per year in the lorcaserin group and 2.1% per year in the placebo group (hazard ratio, 0.99; [95% CI, 0.85 to 1.14]; P<0.001 for noninferiority). In the lorcaserin group versus the placebo group, the rate of extended major cardiovascular events was 4.1% per year and 4.2% per year, respectively, and this comparison did not meet the threshold for superiority (hazard ratio, 0.97 [95% CI, 0.87 to 1.07]; P=0.55).

The ultimate role of lorcaserin, which the FDA approved in 2012 as an adjunct to nonpharmacological weight-loss strategies, is uncertain in real-world practice, an accompanying editorial said. Of note, side effects of the drug (e.g., headache, fatigue, dizziness, diarrhea, and nausea) led to twice the number of trial discontinuations in the lorcaserin group compared to the placebo group, although both groups had similar overall rates of discontinuation, the editorialists wrote.

“For now, the drug may be best used on a cautious basis according to the needs of individual patients,” they wrote.

Finally, the USPSTF reaffirmed its 2012 recommendation to offer intensive, multicomponent behavioral interventions to encourage weight loss in adults with obesity. The B-grade recommendation, published online on Sept. 18 by JAMA, advises that clinicians offer or refer adults with a body mass index of 30 kg/m2 or more to such interventions.

Behavior-based weight loss interventions (e.g., dietary changes, physical activity, and counseling) pose little risk of harm and can improve weight status and reduce the incidence of type 2 diabetes in adults with obesity and elevated plasma glucose levels, the task force wrote.

Comprehensive behavioral treatment for patients with obesity should be foundational in primary care, irrespective of any adjunctive medical or surgical treatments, an accompanying editorial noted. “Clinicians can do their patients a great service by showing respect for their patients' struggles with weight management, screening for obesity-related comorbidities, and providing treatment for identified conditions regardless of the patient's motivation for, or success with, weight-loss treatment,” the editorialist wrote.