Usefulness of fluoxetine in obese non-insulin-dependent diabetics: a multicenter study

Weight reduction is essential in the management of most non-insulin-dependent diabetics, but this therapeutical goal is difficult to obtain. In this double-blind parallel study, 82 non-insulin-dependent diabetics, moderately obese (BMI = 30 - 39 kg/m2), were given for an 8-week period either placebo (P) or fluoxetine (F), a specific serotonin reuptake inhibitor, in addition to their usual antidiabetic treatment. Thirty-nine of them received 60 mg fluoxetine a day and 43 were given the placebo. At admission, both groups had similar weight excess, metabolic control and serum lipid values. In comparison with the P-treated subjects, those treated with fluoxetine (F) lost more weight after 3 weeks (-1.9 vs. -0.7 kg, p < -0.0009) and after 8 weeks (-3.1 vs. -0.9 kg, p < 0.0007). Fasting blood glucose decreased in group F after 3 weeks (-1.5 vs -0.4 mmol/L, p < 0.003) and after 8 weeks (-1.7 vs. -0.02 mmol/L, p < 0.0004). HbAlc decreased from 8.5% to 7.7% in group F and from 8.6% to 8.3% in group P (p = 0.057). Mean triglyceride level was also reduced in group F after 8 weeks (p = 0.042). Fasting C-peptide did not change in either group, but fasting insulin values decreased in group F after 3 weeks (p < 0.02) and after 8 weeks (p < 0.05). The insulin/C-peptide molar ratio decreased significantly in group F after 3 weeks (p < 0.04) and after 8 weeks (p < 0.05) in comparison with group P. The drug was generally well tolerated and no major side effects were reported. In conclusion, the addition of fluoxetine to the usual oral hypoglycemic agent therapy might be beneficial in obese non-insulin-dependent diabetics, at least on a short-term basis.