The Relationship Between Height Velocity and Growth Hormone Secretion in Short Prepubertal Children

Abstract

We have performed 24 h growth hormone (GH) profiles in 50 short prepubertal children aged between 5.2 and 12.9 years, growing with height velocity standard deviation scores (SDS) between 0.4 and -3.9. There was an asymptotic relationship between height velocity and spontaneous GH secretion described by the equation: height velocity SDS = A-B(e-cx), where A, B and C are constants and x is a measure of spontaneous GH secretion. We considered GH pulse amplitude to be the better description of spontaneous GH secretion as duration of the GH pulse (the time component of area under the curve) contributed little to the relationship between height velocity and area under the pulse. The distribution of GH secretion was continuous and there was no dividing point between GH insufficiency and sufficiency. Similar overlap was observed when the results of GH responses to insulin induced hypoglycaemia were considered; 14% of slowly growing children (height velocity SDS less than -0.8), had a response greater than 15 mU/l. Likewise serum IGF-I concentrations could not clearly separate slowly growing children from normal individuals. We conclude that height velocity, which ultimately determines height achieved, is controlled predominantly by GH pulse amplitude. The findings suggest that short normal children growing along or parallel to the third height centile could be made to grow faster by the administration of exogenous GH.

Validated Multivariate Models Predicting the Growth Response to GH Treatment in Individual Short Children with a Broad Range in GH Secretion Capacities

“…Moreover, the GH value obtained during the spontaneous profile better reflects physiologic secretion and the overall secretory pattern. Growth in children has been shown to be modulated by the GH pulse amplitude (23,37,38). This is supported by our results, in which the GH peak is more informative than other estimates from the GH profile.…”

The impact of childhood body mass index on timing of puberty, adult stature and obesity: a follow-up study based on adolescent anthropometry recorded at Christ's Hospital (1936–1964)

“…The changes in height velocity around puberty depend fundamentally on changes in circulating hormone levels, which in themselves are determined to a certain extent by nutrition. 58,59 Given that individuals with a higher prepubertal BMI, presumably reflecting positive energy balance, are better able to cope with the physiological demands of puberty, it is perhaps not unsurprising that these individuals enter puberty earlier.…”

Efficacy of Insulin-Like Growth Factor I Levels in Predicting the Response to Provocative Growth Hormone Testing

“…The 2: 1 male to female ratio in our clinic population evaluated for G H deficiency is typical of the referral patterns reported by others (35,44). This ratio raised a concern that girls with G H deficiency may be underdiagnosed, or that the evaluation of girls for GH deficiency may be delayed.…”

“…Furthermore, although growth velocity has been advocated as an indicator of GH status, we found that statural growth velocity was <5th centile for age for only four of 10 children recently diagnosed with GH deficiency (Lee PDK, unpublished data). Therefore, although statural growth velocity is undoubtedly decreased in GH-deficient children (35), the availability and utility of this observation in an individual patient may be limited.…”