GROWTH HORMONE DEFICIENCY IN SHORT STATURE CHILDREN DIAGNOSED BY INSULIN TOLERANCE TEST IN TERTIARY CARE HOSPITAL, KARACHI, PAKISTAN

Objective: To determine the frequency of Growth Hormone Deficiency by Insulin Tolerance Test in children evaluated for short stature, in PNS Shifa hospital Karachi Pakistan. Materials and Methods: A cross sectional study was conducted in department of pathology, PNS Shifa Hospital Karachi from Oct 2015 to Sept 2016. Children referred by Pediatricians or physicians for workup of short stature to the Chemical pathology and Endocrinology department of PNS Shifa Hospital were evaluated by history, examination and preliminary workup including laboratory investigations. Children with systemic or endocrinal disorders were excluded from the study. Screening for growth hormone deficiency was carried out by exercise stimulation test. The children with growth hormone level of <20 mIU/l on exercise stimulation test were provisionally considered to have GH deficiency, and these were selected for evaluation with Insulin Tolerance Test as per protocol and written consent in this regard was taken. Results and outcome of insulin tolerance test were recorded on predesigned Performa. Results: During the study duration, ninety children were assessed for growth hormone status by exercise stimulation test, in whom systemic and endocrinal causes of short stature were ruled out in preliminary workup. Out of them 72, had GH levels <20 mIU/l on exercise stimulation test and these individuals were subjected to insulin tolerance test as per protocol. The results of insulin tolerance test showed 42 (58.3%) cases as growth hormone deficiency and 30 (41.6%) cases as normal variant of short stature. Conclusion: Growth Hormone deficiency detected by insulin tolerance test was predominant cause of short stature   followed by normal variant Short stature. Key words: Growth hormone deficiency, Insulin tolerance test, Normal variant short stature