Objective: To assess whether valvular lesions are associated with the use of dexfenfluramine in Chinese patients with type 2 diabetes.

Design: Case-control study.

Patients and methods: Thirty-six obese Chinese patients with type 2 diabetes and a history of dexfenfluramine use during the period January 1992 and September 1997 were recruited into the study, while another 43 age- and sex-matched Chinese patients with type 2 diabetes were recruited as controls. The mean age for the cases was 44.1 years (standard deviation, 11.2 years; median, 42.5 years; range, 20-64 years). The 43 control subjects were age- and sex-matched, and had a mean age of 48.5 years (standard deviation, 10.9 years; median, 51.0 years; range, 16-63 years; P>0.05). The male-to-female ratio was confirmed as similar between the two groups (10:26 versus 12:31; P>0.05). All patients were clinically free from cardiovascular disease. Patients with a history of underlying valvular disease from any cause were excluded from the study. All patients underwent echocardiographic assessment, and the presence of any valvular lesions was documented.

Results: The mean duration of dexfenfluramine use by the cases was 21.8 weeks (standard deviation, 29.0 weeks; median, 18.0 weeks; range, 1-160 weeks). Subjects with a history of dexfenfluramine use had higher rates of significant aortic regurgitation, tricuspid regurgitation of any severity, and of any valvular regurgitation, compared to controls (11.1% versus 0%, P<0.05; 30.6% versus 4.7%, P<0.01; and 61.1% versus 34.9%, P<0.05, respectively). Logistic stepwise regression analysis to predict the risk of valvular lesion was conducted, with age, sex, history of dexfenfluramine use, body mass index, waist-hip ratio, blood pressure, fasting plasma glucose, lipid profile, and duration of diabetes as independent variables. A history of dexfenfluramine use was the only significant parameter entered into the model (significant aortic regurgitation: beta=9.19, standard error=46.6, P<0.05; any tricuspid regurgitation: beta=2.76, standard error=10.8, P<0.05).

Conclusion: In Chinese patients with type 2 diabetes, a history of dexfenfluramine use is associated with heart-valve regurgitation, particularly aortic regurgitation.