title: Effect of bromocriptine withdrawal in acromegaly on body composition as assessed by bioelectrical impedance analysis.
abstract: To evaluate the effect of bromocriptine withdrawal after dopaminergic long-term treatment (15.0 +/- 6.8 mg/day, mean +/- SD) in 12 acromegalic patients on body composition, bioelectrical impedance was measured before and at the end of two weeks of drug withdrawal. During withdrawal basal hGH and IGF-I increased from 2.5 +/- 1.9 micrograms/l and 2.1 +/- 0.8 kU/l to 9.1 +/- 11.7 micrograms/l and 4.9 +/- 2.2 kU/l, respectively, and the hGH secretion deteriorated significantly both after oral glucose load and in the TRH test, indicating recurrence of active acromegaly. Reactance and resistance decreased by 5 +/- 4 and 23 +/- 19 omega, respectively (p less than 0.01), whereas body weight remained constant (+0.4 +/- 2.1 kg). Bioelectrical impedance analysis indicated evident shifts in body composition, i.e. a significant reduction of body fat (-2.0 +/- 1.7 kg) and a simultaneous increase in both lean body mass (+2.4 +/- 2.2 kg) and total body water (+1.8 +/- 1.6 l). The changes in body composition were related to a combined effect of unsuppressed hypersomatotropism and the lack of bromocriptine actions other than inhibition of hGH secretion (for example stimulation of the renin-angiotensin-aldosterone system by both the recurred hypersomatotropism and the absence of dopaminergic bromocriptine effects). We conclude that bioelectrical impedance analysis is a good additional tool to assess the pathophysiological effects of bromocriptine withdrawal in long-term treated acromegalic patients.
authors.affiliation: Abteilung für Endokrinologie, Johann Wolfgang Goethe-Universität, Frankfurt, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Rau
authors.forename: H
authors.initials: H
authors.lastname: Fischer
authors.forename: K
authors.initials: K
authors.lastname: Schmidt
authors.forename: B
authors.initials: B
authors.lastname: Lembcke
authors.forename: P H
authors.initials: PH
authors.lastname: Althoff
mesh_terms: D000172:Acromegaly / Q000188:drug therapy*; D000293:Adolescent; D001786:Blood Glucose / Q000032:analysis; D001823:Body Composition; D015992:Body Mass Index; D001834:Body Water; D001835:Body Weight / Q000187:drug effects; D001971:Bromocriptine / Q000494:pharmacology*; D002675:Child, Preschool; D004594:Electrophysiology; D005260:Female; D013006:Growth Hormone / Q000096:biosynthesis; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis; D008297:Male; D010992:Plethysmography, Impedance; D013375:Substance Withdrawal Syndrome
chemical_list: D001786:Blood Glucose; D001971:Bromocriptine; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone