Effectiveness of sibutramine in promoting weight loss in obese people with and without diabetes in a weight management clinic: a retrospective case-cohort study

The efficacy of sibutramine in promoting weight loss is well established in clinical trials but its effectiveness in routine clinical practice is less clear, particularly in people with type 2 diabetes (T2D). We determined weight change over time in 422 people (62% women), of whom 15% had T2D, commenced on sibutramine and hypocaloric diet (<800 kcal/day for ∼ 3 months) between 2007 – 2009 as part of standard treatment in our weight management clinic serving the Greater Manchester population. Patients' mean age was 47 years, and baseline weight 116 kg and body mass index 40 kg/m2. Weight measurements were available for 74%, 46%, 34% and 24% of patients at 0 – 6, 7 – 12, 13 – 18 and 19 – 24 month-intervals, respectively. We used multi-level models with random effects weighted for time difference between baseline and repeated weight measurements, and adjusted for baseline weight, height, history of T2D, gender and age. Patients significantly lost weight over time, with highest magnitude of weight loss achieved at 6 – 9 months.[figure1]Mean [95% confidence interval (CI)] weight losses (kg) achieved respectively at 6 – 12, 13 – 18 and 19 – 24 month-intervals were 10.3 (8.6 – 12.0), 9.7 (7.2 – 12.1) and 9.8 (6.5 to 13.1) for patients without T2D, and 7.8 (5.3 – 10.3), 5.2 (2.1 – 8.2) and 7.5 (3.7 – 11.3) for patients with T2D. Despite high starting weights, 50% of all patients achieved ≥ 5% weight loss from baseline (30% achieved ≥ 10%). In conclusion, sibutramine with a hypocaloric diet in our clinical practice produced significant, early weight loss that was sustained over two years of follow-up. The efficacy was similar in people with and without T2D. The magnitude of weight loss was superior to previous clinical trials, and far superior to results obtained in generalist clinical practice.