Thirty-two patients recruited in the study. All the participants had a diagnosis of T2DM and had at least 1-year follow-up in Endocrinology outpatient clinic. All the study participants were chosen from regulated diabetic subjects whose diabetes treatment were not amended. The investigators excluded any cases needing revision in their treatment strategies due to ethical issues. Participants were recruited in intervention and control groups. Each group consisted of 16 diabetic subjects. Groups were matched for age, diabetes duration, body mass index, baseline HbA1c level and gastrin levels. In the intervention group, all participants had various degrees of symptoms for functional dyspepsia, gastro-oesophageal reflux, gastritis or duodenitis and all of them were prescribed 40 mg of esomeprazole treatment for three months. The control group consisted of without gastric complaints, thus who did not receive PPI drugs. This group was followed-up without any intervention for three months. All subjects were advised for dietary recommendations and lifestyle modifications. At the end of the study, all of them reported their adherence to these recommendations. Subjects, on pioglitazone and incretin-based therapies; subjects with a history of gastrointestinal surgery, liver or kidney disease, diabetic macro- or microvascular complications; who are lactating or pregnant, were excluded. Subjects on any PPI treatment or had a history of PPI use in a 3 months period before the study were not eligible.

The height was measured in the standing position with a tape measure fixed on the wall. Body weight, fat mass, and fat percentage were measured using a conventional bioelectrical impedance (BIA) device (TBF-300, Tanita corp., Tokyo, Japan). All measurements were completed after a mean period of 60 seconds. Subjects were asked not to consume alcohol during the 24-hour period before assessment and caffeine for the 4 hours before assessment. All accessories, such as heavy clothing, rings, and earrings, which could affect the measurements, were removed before the assessment. Body mass index was calculated as weight in kilograms divided by the square of the height in meters (kg/m2). All measurements were performed by one physician after the participants had fasted for at least 8 hours. Fasting blood glucose (FBG) (mg/dl.), triglyceride (mg/dL), high-density lipoprotein cholesterol (HDL-c, mg/dL), low-density lipoprotein cholesterol (LDL-c, mg/dL), thyroid-stimulating hormone (TSH) (IU/mL), HbA1c level (%) and gastrin levels (pmol/L) were measured by using a sample of venous blood. TSH assays were performed via immunochemiluminescent assay (Architect c8200, Abbott). FBG, LDL-c, HDL-c, and triglyceride levels were measured by using the hexokinase 7/G-6-PDH method, a measured liquid-selective detergent method, an accelerator-selective detergent method, and a glycerol phosphate oxidase method (Architect c8200, Abbott), respectively. HbA1c was via the enzymatic method using Architect c4000 (Abbott) system from human complete blood and hemolysate. Serum gastrin level was measured by a competitive radioimmunoassay using a rabbit antiserum raised against a gastrin 17 albumin conjugate (DiaSource ImmunoAssasys S.A., Louvain-la-Neuve, Belgium). According to the manufacturer, the range of gastrin level is 11-54 pmol/L and the lowest detectable concentration is 5 pmol/L. All measurements were performed both at baseline and the follow-up visit.