Study of Metabolism of Bone in Iraqi Children with GH Deficiency Before and After 6 months GH Replacement Therapy

Abstract

Growth hormone (GH), also known as human growth hormone or somatotropin, is a peptide hormone produced by the anterior lobe of the pituitary gland. Stimulates the growth of all body tissues, including bones. Aim of study: In the present study, we have examined the effect of growth hormone on serum bone turnover markers with respect to children with growth hormone deficiency. These markers can be used as predictors for the growth response to growth hormone treatment before and after 6 months of therapy. Patients and methods: The study included (200) samples divided into two groups. The patient group included 100 samples (52 males and 48 females) of children with growth hormone deficiency Informed consent was obtained from parents, For the purpose of comparison, 100 samples (50 females and 50 males) of healthy children corresponding to patients with sex, age, nutritional behavior, and geographical area, were selected as control group Informed consent was obtained from parents ,The study also included age groups for both sexes between (5-12) years and for both infected samples and control group, This study was conducted at the National Center for Diabetes Treatment and Research of the Mustansiriya University in Baghdad and for the period from, (October 2016 to July 2017) Results: Regarding serum (Ca+2) levels there was a highly significantly decreased in children GHD group when compared with healthy children (P<0.001) before treatment, Regarding serum (V.D3) levels there was a highly significantly decreased in children GHD group when compared with healthy children (P<0.001) before treatment, and after 6 months of treatment the results of the study showed that serum (V.D) level had a highly significantly increased in children GHD group compared to before treatment (P <0.001). Levels of Serum phosphorus (PO4_2) and serum alkaline phosphatase (ALP) have also slightly reduced in children with growth hormone deficiency when compared with healthy children. Measuring the serum levels of parathyroid hormone (PTH) is another parameter to be considered in this study the two-sample t test has demonstrated that there is no significant difference between healthy children and those with growth hormone deficiency with respect to parathyroid hormone at baseline. Conclusion: It was concluded from this study that there was a disparate influence of growth hormone on serum bone turnover markers . We can clearly observe the significant influence of growth hormone on vitamin D3 levels in short-term treatment of children with growth hormone deficiency. Serum calcium was the second affected bone marker in this study, where a slight increase in serum calcium level was observed. Although this increment has shown to be ineffective, however we believe that the elevated levels of vitamin D3 is most likely the driven force of calcium absorption that responsible of reducing calcium levels in the blood. Vitamin D3 has known as the key player to improve the absorption of calcium and also involved in maintaining bone mineral homeostasis in addition to regulating renal calcium excretion 42 . Parathyroid hormone has also recognized as an important element adjusting calcium and phosphate homeostasis 43 , however it is hard to claim this hypothesis in the present study. Levels of Serum phosphorus and serum alkaline phosphatase have also slightly reduced as a response of growth hormone therapy in children with growth hormone deficiency. Even though this decrement in levels seems to be ineffective, however it could be attributed to the short treatment plan and more research is required for longer time period.