文档介绍：Growth Hormone Deficiency, GHD 生长激素缺乏症
Department of Endocrinology Children’s Hospital Fudan University
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
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
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
Bone epiphysis
Hypothalamus
Anterior pituitary
SS
(-)
GHRH
(+)
GH
Liver
IGF-1
(-)
Gonads
T E2
Thyroid gland
T3 T4
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
Most causes of GHD are idiopathic
Secondary causes
Brain tumors, monly S S radiation
Anatomical abnormalities (eg, septooptic dysplasia, empty sella syndrome)
ic GHD
Etiology
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
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
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. Oth