Efficacy of Orlistat in type 2 diabetes – a systematic review and meta analysis

Background Obesity is a common comorbidity of Type 2 Diabetes mellitus (T2DM), a chronic metabolic condition affecting millions worldwide. Orlistat may be used to reduce weight as an adjunct to diet/lifestyle changes.

Aim To assess the evidence of orlistat on weight loss in adults with T2DM/high risk of T2DM and obesity.

Design & Setting Systematic review and meta-analysis of randomised controlled trials (RCTs) in clinical settings.

Method Articles were searched in ten databases including Medline, Embase and PsycInfo. RCTs of orlistat in adults with T2DM/at high risk and a body mass index (BMI)≥25 kg/m², with≥12 weeks of follow-up and reported change in weight/BMI were included. A random effects meta-analysis model was used to pool mean differences, I² statistics to assess heterogeneity, and a funnel plot to assess publication bias.

Results Thirty RCTs compared orlistat with a comparator, in conjunction with a weight loss diet. All trials showed statistically significant greater weight loss for the orlistat group. A meta-analysis of 22 studies (n=5,921) showed that the overall weight loss for orlistat was a mean 2.40 kg (95% CI: 2.08, 2.72) greater than in controls. Weight difference was statistically significant between subgroups at 3 months (2.74 kg, 95% CI: 1.20, 4.27), 6 months (2.13 kg, 95% CI: 1.61, 2.66) and 12 months (2.49 kg, 95% CI: 1.89, 3.09).

Conclusions Orlistat resulted in statistically significant greater weight loss in overweight adults with T2DM/high risk compared with controls. Orlistat can be considered an adjunct in T2DM/high risk of T2DM for weight loss along with diet/lifestyle modifications.