Study of the Hormones Controlling Food Intake (Leptin and Agouti Related Protein “AgRP”) in Cannabis Smokers

Abstract

Background: Leptin is an adipocyte derived hormone which is thought to be a key regulator of food intake and body weight. Agouti-related protein also called Agouti-related peptide (AgRP) is a neuropeptide produced in the brain by the AgRP/NPY neuron. It is one of the most potent and long-lasting of appetite stimulators. The appetite stimulating effects of AgRP are inhibited by the hormone leptin. There is a public perception that exposure to cannabis produces an increase of appetite (a phenomenon referred to as the 'munchies'). This phenomenon needs an exploration of the role of the endocannabinoid system in the regulation of obesity and associated metabolic syndrome Aim: This study aimed to find out the food intake style, of subjects smoking cannabis by studing the relationship between the most two popular hormones controlling food intake (leptin hormone, and agouti related protein hormone) compared with healthy subjects. Methods: The study compared two groups of personells; the test group (Group II) included ten males aged 37.40±2.67 years (mean age ±SD) with positive 9-carboxy-Tetrahydrocanabinol (THC) detected in their urine by qualitative analysis using Gas Chromatography-Mass spectrometry. And control group (GroupI) included ten healthy males aged 38.67±2.35 years (mean age ± SD) as volunteers with negative 9-carboxy-Tetrahydrocanabinol (THC). In both groups, age and body mass index (BMI) were matched, diabetic subjects were excluded. Plasma leptin concentration was measured by quantitative radio immunoassay (RIA). Human plasma AgRP hormone was quantitatively measured by using a kit supplied from Quantikine R&D systems INC. Results: In group I (GI), there was an increase in mean plasma leptin concentrations ±SD (6.39±1.93) ng/ml, than that found, in group II (GII) (4.49±1.40) ng/ml, but it's statistically insignificant (P>0.05). There was an elevation, in mean plasma AgRP concentrations (27.77±2.17) pg/ml in GII, comparing with mean plasma AgRP concentrations (25.84±1.93) pg/ml, in GI but it's statistically insignificant (P>0.05). There was a statistically significant inversely correlation between plasma leptin concentrations and plasma AgRP concentrations in GI (P<0.05). There was a proportionally correlation found between plasma leptin concentrations and plasma AgRP concentrations in (GII), but it's statistically insignificant (P>0.05). Conclusion: The relationship between plasma leptin concentrations and plasma AgRP concentrations affected by smoking cannabis, and that may change the mechanism of food intake in cannabis smokers.