Long-term effects of fluoxetine on glycemic control in obese patients with non-insulin-dependent diabetes mellitus or glucose intolerance: influence on muscle glycogen synthase and insulin receptor kinase activity.
Fluoxetine (F) is a specific serotonin-reuptake inhibitor that has been shown to promote weight loss and improve glycemic control in obese diabetic patients. To study its long-term metabolic effect, 40 obese patients with non-insulin -dependent diabetes mellitus (NIDDM) or impaired glucose tolerance (IGT) were included in a 12-month, randomized, placebo controlled study. Patients were assigned to receive either 60 mg F or placebo (P) daily in conjunction with a 5.0-MJ/d diet (> 50% carbohydrate). Both groups showed a significant weight loss, with a nadir after 6 months without group differences (mean +/- SD: F, 10.1 +/- 10.0 kg; P, 9.4 +/- 11.5 kg). Fifteen patients from the F group and 14 from the P group completed the 12-month study without weight loss differences. Glycemic regulation improved along with the weight loss, but with a larger decline in plasma C-peptide and fasting glucose levels on the F group (P < .05). Total skeletal muscle glycogen synthase (GS) activity increased by 31% in the F group (P < .01) and by 17% in the P group (nonsignificant) after 6 months of treatment, but was still less than the activity in normal-weight controls (aged 28.0 +/- 6.3 years; body mass index, 23.5 +/- 2.2). After adjustment for fasting glucose, insulin, weight loss, and diabetic state, a positive effect of F remained on the total GS activity, which accounted for 27% of the variation (P < .05). The waist to hip ratio was reduced in P subjects as compared with F subjects (P < .05). Fat-free mass (FFM) tended to be more reduced in the F group as compared with P subjects (4.9 v 1.9 kg), although the difference did not reach statistical significance. In conclusion, F seems to improve insulin sensitivity beyond the effect mediated through weight loss by a possible effect on GS activity in skeletal muscle tissue.
Breum
L
L
Department of Internal Medicine, Hvidovre Hospital, Denmark.
Bjerre
U
U
Bak
J F
JF
Jacobsen
S
S
Astrup
A
A
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D001823:Body Composition; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D005260:Female; D005473:Fluoxetine / Q000627:therapeutic use*; D018149:Glucose Intolerance; D006006:Glycogen Synthase / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000201:enzymology; D009765:Obesity / Q000097:blood* / Q000150:complications / Q000188:drug therapy*; D011972:Receptor, Insulin / Q000378:metabolism; D017367:Selective Serotonin Reuptake Inhibitors / Q000627:therapeutic use; D013997:Time Factors
D001786:Blood Glucose; D005473:Fluoxetine; D006006:Glycogen Synthase; D011972:Receptor, Insulin; D017367:Selective Serotonin Reuptake Inhibitors