Dexfenfluramine in obese Chinese NIDDM patients. A placebo-controlled investigation of the effects on body weight, glycemic control, and cardiovascular risk factors

OBJECTIVE To investigate the safety, efficacy, and metabolic effects of dexfenfluramine in obese Chinese NIDDM patients. RESEARCH DESIGN AND METHODS Thirty-two patients, mean (± SD) body weight 76.2 ± 8.5 kg with corresponding BMI 31.1 ± 2.1 kg/m2, were randomized into a two-phase study, after a 2-week single-blind run-in period on placebo. Phase 1 was a randomized 3-month double-blind placebo-controlled trial during which either dexfenfluramine or placebo was added to the existing treatment regimens of diet plus or minus sulfonylureas without metformin. Phase 2 was a further 3-month single-blind trial during which the placebo group was given dexfenfluramine without patients' knowledge of changing to active medication, while the active group continued with dexfenfluramine. Body weight, glycemic control, blood pressure, lipids, and quality of life were assessed before and at 3 and 6 months after randomization. A total of 27 patients were also followed for an additional period of 6–12 months (215 ± 53 days) after dexfenfluramine treatment was withdrawn. RESULTS During the run-in period, both groups were comparable for all parameters measured. At 3 months, mean changes in BMI were −1.2 ± 1.0 kg/m2 (dexfenfluramine) vs. −0.1 ± 0.5 kg/m2 (placebo) (P < 0.001). The mean changes in fasting plasma glucose were −1.14 ± 0.99 vs. 0.51 ± 1.34 mmol/l (dexfenfluramine vs. placebo, P = 0.004). HbA1c also significantly improved in the dexfenfluramine group (−0.80 ± 0.53 vs. 0.25 ± 0.64%, P < 0.001). During the 3-month single-blind dexfenfluramine treatment in the ex-placebo group, there were similar improvements in body weight and glycemic indexes. After cessation of dexfenfluramine therapy at 6 months, significant increases in body weight and glycemic indexes, almost back to the baseline, were observed for both groups. CONCLUSIONS Dexfenfluramine aids weight loss and improves glycemic control in obese Chinese NIDDM patients over a 3- to 6-month period. These effects are emphasized after withdrawal of treatment and further support the longer-term use of dexfenfluramine for chronic complicated obesity.