AGA Abstracts Table 1.Baseline characteristics of GERD patients with extra-esophageal symptoms receiving the GERDOFF medical device combined with PPIs or PPI treatment alone. GERDOFF + PPI PPI P values Female, N (%) 62.9% 89.2% 0.0086 Age (years), mean+ 49.2± 15.22 47±14.33 0.5350 s.d Range 20-46 20-46 BMI (kg/m2) 24.1 23.9 0.6162 RSI, total score at 25±6.10 26.1±5.09 0.1097 screening Mean+s.d Likert symptom score at screening 19±4.30 21.1±4.54 0.2632 Mean+s.d. Sa1208 SERUM CONCENTRATION AND PHARMACOKINETICS OF SINGLE AND REPEATED ORAL DOSES OF ESOMEPRAZOLE AND GASTRIN ELEVATION IN HEALTHY MALES AND FEMALES Hólmfrídur Helgadóttir, Sigrun H. Lund, Einar Björnsson, Sveinbjörn S. Gizurarson, Helge Waldum Background: Gastrin elevation is a known but very variable long-term effect of proton pump inhibitor (PPI) therapy. In a recent study females on PPI-therapy had significantly higher fasting and postprandial gastrin levels than males (Helgadottir et al. Dig Liver Dis 2014; 46: 125-130). The reason for this is unclear but differences in serum concentrations of the drug might be different between the genders. Metabolism of PPIs occurs primarily via CYP34A and CYP2C19 and there is a known gender difference in both expression and activity of these two isoenzymes. The aim of the study was to analyze the serum concentrations and the pharmacokinetics of esomeprazole and short-term effect on serum gastrin levels and evaluate potential gender difference. Methods: Healthy volunteers participated in the study. They received a daily single oral dose of 40 mg of esomeprazole for five days. After an overnight fasting, pharmacokinetic blood samples and serum for gastrin measurements were collected at scheduled time-points for 8 hours, initially every 30 min and after 4 hours with 60 min interval after dosing on investigation day one and five. Participants received a standard meal 2 hours post-dose. Esomeprazole was analysed by liquid chromatography method and the pharmacokinetic parameters were estimated using a non-compartmental analysis on the concentration-time data. Gastrin concentrations were measured using radioim- munoassay. Results: A total of 30 volunteers were enrolled, 15 females, median age 24 years (IQR 23-26). Female patients had higher baseline gastrin levels (pM) than males 12 (IQR 10-15) vs. 7 (IQR 4-11) (p=0.03). Median gastrin levels (pM) rose from 10 (IQR 6– 14) to 15 (IQR 13–20) (p=0.0002), which was not influenced by gender (p=0.13). The serum levels for esomeprazole increased by an average of 299.8 ng/mL (p<0.001) from day 1 to day 5. The mean increase was 59.6 ng/mL lower in men than females (p=0.5) (Figure). The mean area under the esomeprazole concentration-time curve was higher among females than males, increased (from 3153 to 5223 vs. 2222 to 4970) with 41% difference on day 1(p=0.3) and 5% on day 5 (p=0.7). Comparison of the esomeprazole pharmacokinetic parameters between males and females revealed no significant gender difference on day 1 or day 5. No significant correlation was found between the area under the esomeprazole concentration-time curve and the gastrin level after repeated oral dosing of 40 mg esomepra- zole for four days (p=0.19). Conclusions: In healthy volunteers, serum gastrin increased significantly after ultra-short-term PPI-therapy. There was also a significant increase in serum esomeprazole levels. There was no significant gender difference in the pharmacokinetics after single or repeated oral doses of esomeprazole 40 mg. The increase in gastrin was not related to gender or esomeprazole concentration. Mean serum concentrations of esomeprazole in healthy female and male volunteers following 40 mg as a single dose (red line) and after 5 days of oral dosing (blue line). S-308 AGA Abstracts Sa1293 TRANSPYLORIC FEED IN GASTROESOPHAGEAL REFLUX ASSOCCIATED APNEA IN PREMATURE INFANTS : A PROSPECTIVE STUDY Tamoghna Biswas, Tapas K. Sabui, somosri Roy, Rakesh Mondal, Subhabrata Majumdar, Sudipta Misra OBJECTIVES: Retrospective studies have reported efficacy and safety of transpyloric feeding in apnea of preterm neonates. This study was designed to prospcetively study this intervention in apnea of prematurity clinically suspected to be due to gastroesophageal reflux. STUDY DESIGN: A single arm prospective interventional study at a tertiary care center of Kolkata, India. Intramural preterm neonates (below 37 weeks of gestation) with apnea and clinical features of gastroesophageal reflux such as back-arching, choking, post-prandial vomiting etc. were included in the study. Newborns with other possible causes of apnea such as sepsis, intracranial hemorrhage, hypoglycemia etc. were excluded. The enrolled neonates underwent continuous transpyloric tube feeding for 72 hours. The primary outcome measure was the difference in number of apneic episodes in 48 hours pre and post initiation of naso-duodenal feeding. Secondary outcome measures included incidence of necrotizing enterocolitis, other gastrointestinal disturbances and mortality. The study was approved by Institutional Review Board, registered with Indian clinical trials registry. Informed consent was obtained from parents of each participant. RESULTS: Sixteen preterm (Age range 4- 23 days, 10 males) neonates were included in the present study. The mean gestational age of the study population was 31.875 ±1.962 (range 28-35 weeks). Eight (50%) were very preterm (gestational age 28-31 weeks). The mean, median and range of the birth weights were 1.354 (±0.342) kg, 1.225 (interquartile range 1.11-1.525) kg and 1-2.3 kgs respectively. Ten (62.5%) were very low birth weight (less than 1500g). The mean maternal age was 23.5 (±3.286) years with a range of 19-32 years.Approximately 1/3 (31.59 %) of the infants were born by Caesarean section, while the rest were born vaginally. Eleven of the sixteen (11/16, 68.75%) neonates showed a documented reduction in the number of apneic episodes within 48 hours of initiation of transpyloric feeding (Figure 1). The mean number of apneic episodes decreased from 1.75 (±0.837) to 0.969 (±0.957) (mean difference 0.781, 95% CI for mean difference 0.249-1.314, p-value=0.007). There were no serious adverse events attributable to transpyloric feeding. CONCLUSION: This study supports previous retrospec- tive studies that in a selected group of preterm neonates with reflux-associated apnea, transpyloric feeding can be a safe, useful and cost effective therapeutic modality. However, this need to be confirmed by controlled trials. Sa1294 PHARYNGEAL AND UPPER ESOPHAGEAL SPHINCTER MOTOR DYNAMICS DURING NORMAL SWALLOW Alisara Damrongmanee, Khalil El-Chammas, Huaiyu Zang, Lin Fei, Neha Santucci, Ajay Kaul Background: Pharyngeal muscle contraction and upper esophageal sphincter (UES) relaxa- tion play a major role during the pharyngeal phase of swallowing. Motor abnormalities of either could lead to feeding or swallowing problems and aspiration. Pharyngeal and UES motor function have been evaluated by high-resolution esophageal manometry in healthy adults and infants with varied results among studied subjects. There is currently no published data on this subject in the pediatric age group. Objective: To determine normative values for pharyngeal contraction and UES relaxation pressures with swallowing in children. Method: We reviewed electronic medical records and high resolution manometry results of children aged ≤ 18 years who had a normal videofluoroscopic swallow study (VFSS). Demographic data, indications, comorbidities, UES metrics (relaxation, integrated relaxation pressure [IRP], resting pressure [URP], and nadir pressure [UNP]) as well as peak pharyngeal pressure (velopharyngeal and meso-hypopharyngeal) were collected. Results: We reviewed the UES metrics in 121 patients; age ranged from 11 months to 18 years (mean 11.4 years) and 47.1% were male. The indications included: dysphagia (59.5%), vomiting/rumination/regurgitation (25.6%), nausea (4.1%) and others (10.8%). The median (followed by interquartile range shown in the bracket) of IRP 0.2 s, 0.4 s, 0.6 s, 0.8 s, URP and UNP were 1.00 [-2.00, 8.00], 4.00 [0.00, 10.50], 10.50 [5.00, 16.50], 17.50 [11.50, 26.50], 54.00 [42.00, 75.00] and -1.00 [-4.50, 5.00] mmHg, respectively. Manometry tracings from 42 patients (of the total 121) included the entire pharyngeal region. Within this group, age ranged from 11 months to 18 years (mean 8.9 years) and 57.1% were male. Indications included: dysphagia (54.7%), vomiting/regurgitation/rumination (28.6%), nausea (2.4%) and others (11.9%) The median and interquartile range of peak velopharyngeal pressure and meso-hypopharyngeal pressure were 252.25 [174.88, 319.00] and 196.25 [143.63, 222.50] mmHg, respectively. Conclusion: This is the largest study reporting UES metrics and pharyngeal pressure changes with swallow in children with normal VFSS. Comparing our results with those reported in