The Role of Ghrelin, Leptin, Adiponectin, Neuropeptide Y, Orexin A, Insulin Like Growth Factor-1(IGF-1), IGFBP-1, IGFBP-3, Corticotrophin-releasing Hormone in Feeding and Nutritional Consequences in Children With Feeding Difficulty.

The investigations plan to prospectively evaluate the plasma concentration of endocrine parameters in children with feeding difficulties. The studied children are arranged to do the dietary records, clinical survey and laboratory studies at the inpatient or outpatient department at clinical evaluation and follow-up. The duration of evaluation and follow-up is 3 months. The healthy children in the control group are also assigned to do the dietary records, clinical survey and laboratory studies after exclusion of feeding difficulty and malnutrition by feeding and nutritional assessment (same survey as the studied patients demonstrated in the following section "clinical survey"). The healthy children do not need the follow-up assessment at 12 weeks.

The diagnosis of feeding difficulty is based on "IMFeD" program. The categorizations of feeding difficulties in the IMFeD tool was originally developed by Dr. Chatoor and Dr. Kerzner (Clinical investigation of feeding difficulties in young children: a practical approach, Clinical Pediatrics, 2009). The 7-day dietary records and assessment of daily calories are evaluated by dietician and research assistant. Nutritional assessment includes 7-day dietary record, assessment of daily calories, body weight (BW), body height (BH), weight for age z-score, height for age z-score, BMI, BMI for age z-score, weight for height index, weight-for-height z-score, severity of malnutrition, and nutritional serum markers (hemoglobin, lymphocyte count, pre-albumin, albumin, ferritin, and zinc). Growth standards for height, weight, and BMI based on World Health Organization (WHO) population were used to obtain z-scores for each measurement, according to age and gender. The severity of malnutrition is determined by weight-for-height.

The laboratory studies will be performed at baseline and at 12 weeks. Venous blood is collected in Serum separation tubes and kept at 4 °C for 1 before being centrifuged, and the serum is stored at -80 °C. All measurements are performed in the same assay without extraction. Concentrations of serum ghrelin, leptin, adiponectin, NPY, orexin A, IGF-1, IGFBP-1, IGFBP-3 and CRH are all determined using enzyme-linked immunosorbent assay (ELISA) kits. All assays were performed according to the manufacturers' instructions.