GROWTH HORMONE ESTIMATION;

Insulin-like growth factor-1 a possible alternative

Abstract

Introduction: Despite the use of growth hormone replacement therapy for decades, our ability to make a definitive diagnosis
of growth hormone deficiency in children is limited. Growth hormone stimulation tests have been used to discriminate between Growth
hormone deficiency and idiopathic short stature. However all these tests lack reproducibility, accuracy, cost affectivity and safety. Insulinlike
growth factor-1 is an effector hormone and its serum level may be used as simple, easy to perform diagnostic test for growth
hormone deficiency. Objective: To determine the efficacy of IGF-1 as a diagnostic tool in children with growth hormone deficiency. Study
Design: Prospective cross sectional survey. Place of Study: Departments of Pediatrics and Pathology, Shalamar Medical & Dental
College, Lahore. Duration of study: 1st July to 31st December, 2011. Material & Methods: We included 40 children of 3.5 – 17 year age
and detailed clinical data was collected. All these children were subjected to stimulation by standardized exercise on treadmill, after taking
basal blood samples for GH and IGF-1. Post stimulation growth hormone was recorded to identify growth hormone deficient children.
Results: 17 (42.5%) children had post stimulation growth hormone level <10ng/ml while 23 (57.5%) had values >10ng/ml. Post
exercise stimulation GH level showed weak correlation with IGF-1 in either of the two study groups. P value was found >0.05 in deficient
as well as sufficient groups, depicting non significance of IGF-1 in relation to post stimulation GH level. Conclusions: IGF-1 is not a
suitable surrogate diagnostic marker for growth hormone deficiency. Diagnosis should always be based on combination of auxological
biochemical, radiological and genetic considerations, Abbreviations: GHD – Growth Hormone Deficiency, GH – Growth Hormone,
GHSTs – Growth Hormone Stimulation Tests, IGF-1 – Insulin-like Growth Factor-1, MPH – Mid Parental Height, BA – Bone Age.