Mechanisms, Pathophysiology, and Management of Obesity

The effectiveness of intentional weight loss in reducing cardiovascular disease (CVD) events in type 2 diabetes is unknown. This report describes 1-year changes in CVD risk factors in a trial designed to examine the long-term effects of an intensive lifestyle intervention on the incidence of major CVD events. This study consisted of a multicentered, randomized, controlled trial of 5,145 individuals with type 2 diabetes, aged 45-74 years, with BMI >25 kg/m2 (>27 kg/m2 if taking insulin). An intensive lifestyle intervention (ILI) involving group and individual meetings to achieve and maintain weight loss through decreased caloric intake and increased physical activity was compared with a diabetes support and education (DSE) condition. Participants assigned to ILI lost an average 8.6% of their initial weight vs. 0.7% in DSE group (P < 0.001). Mean fitness increased in ILI by 20.9 vs. 5.8% in DSE (P < 0.001). A greater proportion of ILI participants had reductions in diabetes, hypertension, and lipid-lowering medicines. Mean A1C dropped from 7.3 to 6.6% in ILI (P < 0.001) vs. from 7.3 to 7.2% in DSE. Systolic and diastolic pressure, triglycerides, HDL cholesterol, and urine albumin-to-creatinine ratio improved significantly more in ILI than DSE participants (all P < 0.01). At 1 year, ILI resulted in clinically significant weight loss in people with type 2 diabetes. This was associated with improved diabetes control and CVD risk factors and reduced medicine use in ILI versus DSE. Continued intervention and follow-up will determine whether these changes are maintained and will reduce CVD risk.

To formulate clinical practice guidelines for the pharmacological management of obesity.

Thirty-six percent of US adults are obese, and many cannot lose sufficient weight to improve health with lifestyle interventions alone. To conduct a systematic review of medications currently approved in the United States for obesity treatment in adults. We also discuss off-label use of medications studied for obesity and provide considerations for obesity medication use in clinical practice. A PubMed search from inception through September 2013 was performed to find meta-analyses, systematic reviews, and randomized, placebo-controlled trials for currently approved obesity medications lasting at least 1 year that had a primary or secondary outcome of body weight change, included at least 50 participants per group, reported at least 50% retention, and reported results on an intention-to-treat basis. Studies of medications approved for other purposes but tested for obesity treatment were also reviewed. Obesity medications approved for long-term use, when prescribed with lifestyle interventions, produce additional weight loss relative to placebo ranging from approximately 3% of initial weight for orlistat and lorcaserin to 9% for top-dose (15/92 mg) phentermine plus topiramate-extended release at 1 year. The proportion of patients achieving clinically meaningful (at least 5%) weight loss ranges from 37% to 47% for lorcaserin, 35% to 73% for orlistat, and 67% to 70% for top-dose phentermine plus topiramate-extended release. All 3 medications produce greater improvements in many cardiometabolic risk factors than placebo, but no obesity medication has been shown to reduce cardiovascular morbidity or mortality. Most prescriptions are for noradrenergic medications, despite their approval only for short-term use and limited data for their long-term safety and efficacy. Medications approved for long-term obesity treatment, when used as an adjunct to lifestyle intervention, lead to greater mean weight loss and an increased likelihood of achieving clinically meaningful 1-year weight loss relative to placebo. By discontinuing medication in patients who do not respond with weight loss of at least 5%, clinicians can decrease their patients' exposure to the risks and costs of drug treatment when there is little prospect of long-term benefit.