Growth Hormone Deficiency, GHD 生长激素缺乏症 Department of Endocrinology Children's hospital Fudan University
Growth Hormone Deficiency, GHD 生长激素缺乏症 Department of Endocrinology Children’s Hospital Fudan University
Introduction GHD is a disorder involves the pituitary gland Pituitary gland does not produce enough Gh Growth velocity is slower than normal GHD can occur at any age
• GHD is a disorder involves the pituitary gland • Pituitary gland does not produce enough GH • Growth velocity is slower than normal • GHD can occur at any age Introduction
Pathogenesis Growth hormone (GH) is a hormone that stimulates normal growth of bones and tissues GHD may result from disruption of the gh aXIs GHD may be isolated (isolated GHD)or associated with other pituitary deficiencies
• Growth hormone (GH) is a hormone that stimulates normal growth of bones and tissues • GHD may result from disruption of the GH axis • GHD may be isolated (isolated GHD) or associated with other pituitary deficiencies Pathogenesis
Pathogenesis GH is stimulated by gh-releasing hormone (GHRH) from the hypothalamus GH is stimulated by certain GH-releasing peptides ( grps) Somatostatin is secreted by the hypothalamus inhibits gh secretion
• GH is stimulated by GH-releasing hormone (GHRH) from the hypothalamus • GH is stimulated by certain GH-releasing peptides (GHRPs) • Somatostatin is secreted by the hypothalamus inhibits GH secretion Pathogenesis
GH Axis Hypothalamus GHRH (-) Thyroid gland-Anterior pituitary Gonads GH T E Liver IGF-1 Bone epiphysis
GH Axis Bone epiphysis Hypothalamus Anterior pituitary SS (-) GHRH (+) GH Liver IGF-1 (-) Gonads T E2 Thyroid gland T3 T4
Pathogenesis insulinlike growth factor 1(IGF-1)is secreted and acts locally at the site of growing bone GF-1 binds to one of several IGF-binding proteins (IGFBPs)and circulates almost entirely (99%)in the bound state IGFBP-3 accounts for the majority of IGF-I binding and this binding proteins activity depends directly on GH
• insulinlike growth factor 1 (IGF-1) is secreted and acts locally at the site of growing bone • IGF-1 binds to one of several IGF-binding proteins (IGFBPs) and circulates almost entirely (>99%) in the bound state • IGFBP-3 accounts for the majority of IGF-I binding and this binding protein’s activity depends directly on GH Pathogenesis
Etiology Most causes of ghd are idiopathic Secondary causes Brain tumors most commonl craniopharyngioma CNS surgery · CNS radiation Anatomical abnormalities(eg, septooptic dysplasia, empty sella syndrome) ° Genetic ghd
• Most causes of GHD are idiopathic • Secondary causes • Brain tumors, most commonly craniopharyngioma • CNS surgery • CNS radiation • Anatomical abnormalities (eg, septooptic dysplasia, empty sella syndrome) • Genetic GHD Etiology
Clinical Presentation Short stature Low growth velocity for age and pubertal stage Increased amount of adipose tissue around the waist The child may look younger Delayed tooth development Delayed onset of puberty Episodes of hypoglycemia
• Short stature • Low growth velocity for age and pubertal stage • Increased amount of adipose tissue around the waist • The child may look younger • Delayed tooth development • Delayed onset of puberty • Episodes of hypoglycemia Clinical Presentation
Laboratory studies 1. GH stimulation test Provocative stimuli include insulin, arginine, levodopa (I-dopa), clonidine and glucagon GH response to insulin is the most reliable test for GHD GH response( GH level <10 ng/m)after given 2 provocative stimuli diagnoses gh deficiency
1. GH stimulation test • Provocative stimuli include insulin, arginine, levodopa (l-dopa), clonidine and glucagon • GH response to insulin is the most reliable test for GHD. • GH response ( GH level <10 ng/ml) after given 2 provocative stimuli diagnoses GH deficiency Laboratory Studies
Laboratory studies 2. Bone age 3. Head mri or ct 4. IGF-1 and igfbp-3 levels Low values of igf-i and igfbp-3 suggest GHD 5. Other pituitary hormones 6. Karyotype
2. Bone age 3. Head MRI or CT 4. IGF-1 and IGFBP-3 levels – Low values of IGF-1 and IGFBP-3 suggest GHD 5. Other pituitary hormones 6. Karyotype Laboratory Studies