Diagnosis of GH Deficiency Without GH Stimulation Tests

Abstract

Growth hormone deficiency (GHD) is the most commonly affected pituitary hormone in childhood with a prevalence of 1 in 4000–10000 live births. GH stimulation testing (GHST) is commonly used in the diagnostic workup of GHD. However, GHD can be diagnosed in some clinical conditions without the need of GHST. The diagnosis of GHD in newborns does not require stimulation testing. Likewise infants/children with delayed growth and/or short stature associated with neuroradiological abnormalities and one or more additional pituitary hormone deficiencies may not need GHST. This review summarizes the current evidence on the diagnosis of GHD without stimulation tests.

Delayed Diagnosis of Congenital Combined Pituitary Hormone Deficiency including Severe Growth Hormone Deficiency in Children with Persistent Neonatal Hypoglycemia—Case Reports and Review

“…Results of hormonal testing showed an undetectable level of cortisol (0.00 µg/dL, normal range: 5–25) during hypoglycemia and an inappropriately low concentration of ACTH (5.74 pg/mL; normal range: 0–46). GH levels assessed a few times during hypoglycemia were very low (0.21–0.56 ng/mL) with respect to values expected in GH-sufficient children of this age [ 7 , 8 , 9 ]. Serum insulin-like growth factor-1 (IGF-1) was undetectable (below 15 ng/mL; normal range < 15–272); free thyroxine (FT4) concentration was low (0.62 ng/dL; normal range: 0.85–1.60); TSH was normal (4.884 µIU/mL; normal range: 0.880–5.420), but inadequately low with respect to FT4.…”

“…Current knowledge on GH’s influence on ovaries has recently been discussed by Devesa and Caicedo [ 48 ], and interactions between GH/IGF-1 and testicular function by Tenuta et al [ 49 ]. However, GH secreted by the pituitary gland of the fetus seems to have no evident effects on intrauterine growth, as the birth sizes of newborns with congenital GHD are, in general, within the normal range [ 1 , 8 , 9 , 18 ].…”

“…In addition, IGF-1 and IGFBP-3 are low in such children; however, in the youngest age groups, the lower limit of the normal range of IGF-1 may be below the sensitivity of the assay. Auxological assessment, especially confirming short stature, is not a question in newborns and infants, as the birth size of children with CPHD is usually normal [ 1 , 8 , 9 , 18 ].…”

Current view on the diagnostics of growth hormone deficiency in childhood and adolescence

“…(2,7) Biochemické vyšetření sekrece růstového hormonu Vzhledem k pulzatilnímu charakteru sekrece růstového hormonu a jeho velmi nízké sérové koncentraci mezi jednotlivými pulzy (často pod detekčním rozmezím laboratorních esejí) nelze diagnostikovat deficit GH z náhodně odebraného vzorku krve. (8) K orientačnímu zhodnocení sekrece GH se využívá vyšetření IGF-1 (inzulinu podobného růstového faktoru typ 1), k potvrzení GHD následně stimulační testy sekrece GH. (2,7)…”

Testes farmacológicos de estímulo de GH em crianças e adolescentes: análise dos exames realizados no HCFMRP-USP nos últimos 15 anos

“…20,25 Além disso, mostra-se um marcador útil já que, devido à alta afinidade do IGF-1 a IGFBPs e ALS, sua concentração sérica ao longo do dia é mais estável e sofre menos alterações que a concentração de GH a estímulos agudos. 29,30 No entanto, apesar de a dosagem basal de IGF-1 ser mais confiável do que a dosagem basal de GH, seu valor pode ser influenciado por outros fatores que devem ser levados em consideração na ocasião da interpretação do exame: a desnutrição, o hipotireoidismo e presença de doenças crônicas (diabetes, hepatopatias, doença renal crônica, entre outros) levam a valores de IGF-1 mais baixos; por outro lado, o IGF-1 tende a aumentar desde o nascimento até a puberdade, quando atinge valores máximos principalmente no sexo masculino, e volta a diminuir em idades mais avançadas. 25,29,32 Desta forma, os valores de normalidade de referência devem levar em consideração todos estes fatores.…”