I investigated the effects of continuous administration of fluoxetine, a serotonin reuptake inhibitor, on energy expenditure, body temperature, and thyroid and catecholamine metabolism during weight reduction using a very low calorie diet (VLCD, Optifast, 1757 kJ/day) followed by a balanced deficit diet (BDD, 5016 kJ/day). Fluoxetine (60 mg/day by mouth, n = 10) or placebo (n = 10) were administered during 3 weeks of inpatient VLCD followed by 8 weeks of outpatient BDD in a double-blind, randomized design. A similar amount of weight was lost in both groups during the VLCD, but by the end of the BDD total weight loss in the fluoxetine group was significantly greater (11.0 $ pm$ 1.1 kg vs. 7.0 $ pm$ 1.0 kg, mean $ pm$ SEM, p $<$ 0.015). Resting metabolic rate (RMR) increased by 4.4 $ pm$ 1.8% (p $<$ 0.01) in the fluoxetine group but did not change in the placebo group during the first week of the VLCD, but subsequently decreased significantly in both groups as dieting continued. However, RMR remained consistently higher in the fluoxetine group for the duration of the VLCD period. No further change in RMR occurred in either group during the BDD period. The thermic effect of food did not change after VLC dieting plus fluoxetine or placebo treatment. Body temperature increased within 2 days of fluoxetine treatment by a mean of 0.3$ sp circ$C, p $<$ 0.025 and remained elevated throughout the VLCD but was unchanged in the placebo group. VLCD therapy reduced serum levels of T$ sb3$, free T$ sb3$ Index and 24-hour urinary excretion of dopamine, norepinephrine, metanephrine and normetanephrine equivalently in both groups. A thermogenic effect of fluoxetine is demonstrated in humans for the first time. The anorectic effect of fluoxetine may be related to its temperature elevating effect.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.69699 |
| Date | January 1993 |
| Creators | Bross, Rachelle |
| Contributors | Hoffer, L. John (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (School of Dietetics and Human Nutrition.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001382955, proquestno: AAIMM91797, Theses scanned by UMI/ProQuest. |
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