Long-term pharmacotherapy for overweight and obesity: a systematic review and meta-analysis of randomized controlled trials

Abstract

CONTEXT: Safe and effective strategies to curb rising obesity prevalence rates are urgently needed and medications may play a more prominent role in future therapeutic regimens. OBJECTIVE: To review systematically the long-term efficacy and safety of approved antiobesity medications. DATA SOURCES: MEDLINE, EMBASE, the Cochrane Controlled Trials Register, Current Science Meta-register of Controlled Trials, and reference lists of original studies and reviews were searched. Drug manufacturers and two obesity experts were contacted. No language restrictions were imposed. STUDY SELECTION: Double-blind, randomized controlled studies of approved antiobesity medications with follow-up periods of 1 y or greater were eligible for inclusion. DATA EXTRACTION: Two reviewers independently assessed all potentially relevant studies for inclusion and methodological quality using standardized abstraction forms. RESULTS: A total of 11orlistat (n ¼ 6021) and three sibutramine (n ¼ 929) studies met inclusion criteria. Attrition rates averaged 33% in orlistat studies and 48% in sibutramine studies. A random effects model was used for meta-analysis. Compared to placebo, orlistat-treated patients displayed a 2.7 kg (95% CI: 2.3-3.1 kg) or 2.9% (95% CI: 2.3-3.4%) greater reduction in weight and patients on sibutramine displayed a 4.3 kg (95% CI: 3.6-4.9 kg) or 4.6% (95% CI: 3.8-5.4%) greater weight reduction after 1 y of follow-up. The number of patients achieving 10% or greater weight loss was 12% (95% CI: 8-16%) higher with orlistat and 15% (95% CI: 4-27%) higher with sibutramine compared to placebo. Orlistat caused gastrointestinal side effects and sibutramine increased blood pressure and pulse rate. CONCLUSION: There is a relative paucity of long-term studies of antiobesity agents. In weight loss trials of 1-y duration, orlistat and sibutramine appear modestly effective in promoting weight loss. Longer, more methodologically rigourous studies that are powered to examine end points such as mortality and cardiovascular morbidity are required.

Efficacy and tolerability of rimonabant in overweight or obese patients with type 2 diabetes: a randomised controlled study

“…First, although consistent with that of previous 1-year studies in overweight or obese patients, 49 including those done in patients with type 2 diabetes, 48 the retention rate of about 66% in all treatment groups might be considered as rather low. One should note that the dropout rate in this study was lower than in previously reported studies with rimonabant in non-diabetic patients.…”

Systematic review of long-term weight loss studies in obese adults: clinical significance and applicability to clinical practice

“…117,118 We also did not assess the mechanisms, benefits, and risks of specific weight loss methods, which have been addressed elsewhere. 7,103,[114][115][116] Our findings have potential clinical implications. First, in obese people with cardiovascular risk factors, weight loss can provide some health benefits.…”

“…Our review can be differentiated from other reviews of weight loss, which included studies with a short follow-up duration, did not specify the study selection process, or did not assess applicability to clinical practice. 7,[103][104][105][106][107][108][109][110][111][112][113][114][115][116] Our review has some limitations. We did not assess supplementary weight loss methods, such as behavioral or exercise programs, when used as stand-alone interventions.…”

Long-term health and psychosocial outcomes from surgically induced weight loss: results obtained in patients not attending protocolled follow-up visits

“…[3][4][5] In controlled clinical trials many efforts are undertaken to keep patients stick to the study. Intensification of contacts with care-givers has been shown to improve the outcome, at least in the short-term.…”