Short-term changes in growth and urinary growth hormone, insulin-like growth factor-I and markers of bone turnover excretion in healthy prepubertal children.
Childhood growth is a non-linear process. To assess whether there is a biochemical correlate of non-linear growth, we have measured free pyridinoline (fPYR) and deoxypyridinoline (fDPYR) excretion in seven healthy prepubertal children, aged 6.1-7.7 years. To examine the link between short-term growth and hormone output, urinary growth hormone (uGH) and insulin-like growth factor-I (uIGF-I) were also measured. Height and weight were measured and a timed overnight urine was collected three times per week from September to July, with results expressed as a weekly change in height (Dheight(w)) or weight (Dweight(w)), and as weekly average hormone or bone marker excretion (uGH(w), uIGF-I(w), fPYR(w), fDPYR(w)). Subject specific SD scores (SDS) were derived for each variable.Dheight(w)and Dweight(w)did not correlate to uGH(w), uIGF-I(w), fPYR(w)or fDPYR(w). Dheight(w)SDS was weakly but significantly correlated to fPYR(w)SDS (r = +0.16;P<0.05) and fDPYR(w)SDS (r = +0.15;P<0.05). The percentage of high frequency (2-4 weeks) variation in uGH(w)excretion, as defined by time series analysis, was correlated with the mean uIGF-I(w)(r = +0.81;P<0.05), which in turn was significantly reduced (92 +/- 38 vs 120 +/- 47 ng;P<0.001) during periods of slow growth (Dheight(w)< 0.05 cm/week). We conclude that in normal children the amount of urinary fPYR, fDPYR, GH and IGF-I does not provide a direct biochemical correlate of growth from week to week. However good growth is associated with a relative increase in fPYR and fDPYR excretion, while poor growth is associated with reduced IGF-I excretion, which in turn is influenced by the temporal secretory pattern of GH over 2-4 weeks.
Tillmann
V
V
Department of Child Health, Royal Manchester Children's Hospital, Pendlebury, Manchester, M27 4HA, UK.
Gill
M S
MS
Thalange
N K
NK
Birkinshaw
G
G
Price
D A
DA
Fraser
W D
WD
Clayton
P E
PE
D000596:Amino Acids / Q000652:urine; D015415:Biomarkers; D001827:Body Height; D001835:Body Weight; D002648:Child; D005260:Female; D006128:Growth / Q000502:physiology*; D019382:Human Growth Hormone / Q000652:urine*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000652:urine*; D008297:Male; D015233:Models, Statistical; D013997:Time Factors
D000596:Amino Acids; D015415:Biomarkers; D019382:Human Growth Hormone; C015484:pyridinoline; D007334:Insulin-Like Growth Factor I; C036020:deoxypyridinoline