Acute effects of intravenous cocaine administration on serum concentrations of ghrelin, amylin, glucagon-like peptide-1, insulin, leptin and peptide YY and relationships with cardiorespiratory and subjective responses

Abstract

Background: Food intake and use of drugs of abuse like cocaine share common central and peripheral physiological pathways. Appetitive hormones play a major role in regulating food intake; however, little is known about the effects of acute cocaine administration on the blood concentrations of these hormones in cocaine users.

Methods: We evaluated serum concentrations of six appetitive hormones: ghrelin (total and acyl-ghrelin), amylin, glucagon-like peptide-1 (GLP-1), insulin, leptin and peptide YY (PYY), as well as acute cardiorespiratory and subjective responses of 8 experienced cocaine users who received 25mg intravenous (IV) cocaine.

Results: Serum concentrations of GLP-1 (p=0.014) and PYY (p=0.036) were significantly decreased one hour following IV cocaine administration; there was a trend towards a decrease for insulin (p=0.055) and amylin (p=0.063) concentrations, while no significant IV cocaine effect was observed for ghrelin (total or acyl-ghrelin) or leptin concentrations (p's≫>0.5). We also observed associations between hormone concentrations acutely affected by IV cocaine (GLP-1, PYY, insulin, amylin) and some cocaine-related cardiorespiratory and subjective responses (e.g., increased heart and respiratory rates; feeling high and anxious).

Discussion: These findings show a significant effect of acute IV cocaine administration on some appetitive hormones and suggest potential associations between these hormones and cocaine-related cardiorespiratory and subjective responses. Additional research is needed to further investigate the potential mechanisms underlining these associations.

Trial registration: ClinicalTrials.gov NCT01851473.

Keywords: Appetitive hormones; Cardiorespiratory responses; IV cocaine administration; Subjective responses.

Conflict of interest statement

Conflict of interest

The authors report no conflicting biomedical financial interests.

Published by Elsevier B.V.

Figures

Fig. 1. Schematic of study assessments, blood collections for hormone measurements, subjective responses to cocaine (SRC) and cardiorespiratory responses to cocaine (CRC)

*CRC: Cardiorespiratory responses to cocaine include systolic and diastolic blood pressure, heart rate, and respiratory rate. **SRC: Subjective Responses to Cocaine include “Crave Cocaine”, “Want Cocaine”, “Like Cocaine”, “Strong Drug Effect”, “Good Drug Effect”, “Bad Drug Effect”, “High”, “Rush”, “Elated”, “Stimulated”, “Suspicious”, “Anxious” and “Tired” assessed with 100 mm visual-analogue scales.

Fig. 2. Differences in appetitive hormone concentrations pre- and post-intravenous (IV) cocaine administration

IV cocaine administration significantly decreased (A) GLP-1 (p = 0.014) and (B) PYY (p = 0.036) concentrations, induced a tendency for decrease for (C) Insulin (p = 0.055) and (D) Amylin (p = 0.063), but had no effect on (E) Acyl-Ghrelin (p = 0.48), (F) Total Ghrelin (p = 0.73), or (G) Leptin concentrations (p = 0.62). Data are presented as mean and standard error of the mean (SEM).