The Preproghrelin 3056 TT Genotype is Associated with the Feeling of Hunger and Low Acylated Ghrelin Levels in Japanese Patients with <i>Helicobacter pylori</i>-negative Functional Dyspepsia

Abstract

An impairment of gastric motility is strongly associated with the pathophysiology of functional dyspepsia (FD). Plasma ghrelin is one of the key molecules linked to gastric motility. Therefore, this study aimed to evaluate whether ghrelin (GHRL) gene polymorphisms are associated with clinical symptoms, the plasma ghrelin levels and gastric emptying in patients with FD as defined by the Rome III classification. We enrolled 74 Helicobacter pylori-negative patients presenting with typical symptoms of FD (epigastric pain syndrome (EPS), n=23; postprandial distress syndrome (PDS), n=51) and 102 healthy volunteers. Gastric motility was evaluated according to the Tmax value and T1/2 using the (13)C-acetate breath test. We used the Rome III criteria to evaluate upper abdominal symptoms and SRQ-D scores to determine the depression status. The Arg51Gln(346G->A), preproghrelin3056T->C, Leu72Met(408C->A) and Gln90Leu(3412T->A) polymorphisms were analyzed in DNA in blood samples obtained from the enrolled subjects. Genotyping was performed using polymerase chain reaction. There was a significant relationship (p=0.048) between the preproghrelin 3056TT genotype and the serum levels of acylated ghrelin in the H. pylori-negative FD patients. The preproghrelin 3056TT genotype was significantly (p=0.047) associated with the feeling of hunger in the H. pylori-negative FD patients. The preproghrelin 3056TT genotype is significantly associated with the acylated ghrelin levels and the feeling of hunger in H. pylori-negative FD patients. Further studies are needed to clarify the association between the preproghrelin 3056TT genotype and lower plasma acylated ghrelin levels and the impact of this relationship on the feeling of hunger in H. pylori-negative FD patients.