The association of the rs1049353 polymorphism of the CNR1 gene with hypoadiponectinemia

The endocannabinoid system (ECS) is an important physiological system that modulates appetite, food intake, energy homeostasis, substance addiction. It is comprised of the cannabinoid receptors (CB1 and CB2), the endogenous lipid ligands of these receptors and the enzymes that mediate the endogenous ligands' biosynthesis and degradation. CB1 receptor is expressed in the brain, adipose tissue, liver, skeletal muscle, gastrointestinal tract and pancreas. The CB1 receptor is encoded by CNR1 gene located at 6q14-q15 level. The aim of our study was to investigate the possible correlation between rs1049353 polymorphism of the CNR1 gene with levels of adiponectin in a group of subjects from Romania. The study included 305 subjects divided in two groups according to their fasting adiponectin levels. Fasting adiponectin levels were determined using ELISA technique. The genotyping of the rs1049353 polymorphism of the CNR1 gene was made using the Real-Time PCR technique. The statistical analysis was performed using De Finetti's program. The differences between the allelic frequencies indicated that the presence of G-wild allele seems to confer risk for expressing low levels of adiponectin (OR=1.917; 95% C.I.=1.353-2.715; p=0.00023) and A-mutant allele seems to be protective (OR=0.522; 95% C.I.=0.368-0.739; p=0.00023). At the test of allelic positivity, the presence of the G-allele conferred risk of hypoadiponectinemia (OR=2.113; 95% C.I.=1.324-3.373). In conclusion, this study indicates that the rs1049353 polymorphism of the CNR1 gene is associated with decreased levels of adiponectin. Further research is needed in order to elucidate the link between the polymorphisms of the CNR1 gene and adiponectin levels.