Orlistat is an effective adjunctive treatment to lifestyle modifications in the treatment of
obesity. While the majority of current evidence is on the effect of
orlistat in obese patients without diabetes, some studies suggest that patients who are obese and have
diabetes mellitus lose more weight and have greater improvements in diabetic outcomes when treated with
orlistat plus a lifestyle intervention than when treated by lifestyle interventions alone. The aim of this study was to review the evidence of the effects of
orlistat on glycaemic control in
overweight and obese patients with
type 2 diabetes. A systematic review of randomized controlled trials of
orlistat in people with
type 2 diabetes reporting diabetes outcomes in studies published between January 1990 and September 2013 was conducted. We searched for articles published in English in MEDLINE and EMBASE. Inclusion criteria included all randomized controlled trials of
orlistat carried out on adult participants with a body mass index of 25 kg m(-2) or over diagnosed with
type 2 diabetes, which reported weight change and at least one diabetic outcome. A total of 765 articles were identified out of which 12 fulfilled the inclusion criteria. The overall mean
weight reduction (3, 6 and 12 months) in the
orlistat group was -4.25 kg (95% CI: -4.5 to -3.9 kg). The mean weight difference between treatment and control groups was -2.10 kg (95% CI: -2.3 to -1.8 kg, P < 0.001), the mean HbA1c difference was -6.12 mmol mol(-1) (95% CI: -10.3 to -1.9 mmol mol(-1) , P < 0.004) and the mean fasting
blood glucose difference was -1.16 mmol L(-1) (95% CI: -1.4 to -0.8 mmol L(-1) , P < 0.001). Treatment with
orlistat plus lifestyle intervention resulted in significantly greater
weight loss and improved glycaemic control in
overweight and obese patients with
type 2 diabetes compared with lifestyle intervention alone.