Change in Total Body Water as a Predictive Tool for Growth Hormone Treatment Response

Abstract

Background/Aims: To investigate whether short-term changes in body composition as a result of growth hormone therapy could be used to predict its growth effect after 1 year in children with growth hormone deficiency (GHD) and children born small for gestational age (SGA). Methods: 88 GHD children and 99 SGA children who started treatment with recombinant human growth hormone were included. Total body water (TBW) and height were measured. After 1 year, patients were divided into adequate and inadequate responders. Results: In GHD and SGA children a sensitivity of 87 and 53%, respectively, and a specificity of 58 and 83%, respectively, were found. The positive predictive values for GHD and SGA children were 73 and 90%, respectively. The negative predictive values were 75 and 32%, respectively. Conclusion: Changes in body composition data measured by TBW are a valuable tool to correctly predict 75% of the GHD children and are only useful in SGA children when the change in TBW is above the cut-off value of 0.7 l/m².

Isolated Growth Hormone Deficiency (GHD) in Childhood and Adolescence: Recent Advances

“…More recently, these observations were expanded in a cohort of 88 children with GHD who had total body water measured with an isotope dilution method, before and 6 weeks after treatment with rhGH (35 g/kg/d). In this case, the change in total body water was a predictor of the first-year rhGH response in terms of height (change in height SDS Ͼ0.7); a change in total body water of Ͼ0.7 L/m 2 identified correctly 73% of good responders to rhGH (409). Apart from the short-term change during treatment, the baseline body composition may also be a predictive factor (410).…”

Effect of growth hormone treatment on energy expenditure and its relation to first-year growth response in children

“…This study shows that 6 weeks of GH treatment has a positive effect on energy expenditure and body composition in children. Body composition changed by an increase in FFM as was demonstrated before in several studies (Ernst et al 2012 ; Vaisman et al 1992 , 1994 ; Gregory et al 1991 , 1993 ; Walker et al 1990 ; Khadilkar et al 2014 ; Boot et al 1997 ; Hassan et al 1996 ). At the same time, total energy expenditure, measured by the DLW technique and energy expenditure at rest, measured by the ventilated hood method, showed an increase by 7% and 5% respectively.…”

“…Beside its growth-promoting effect, GH has many specific metabolic effects as well, including (1) increased mobilization of fatty acids from adipose tissue and increased use of fatty acids for energy, (2) increased rate of protein synthesis in most cells of the body, and (3) decreased rate of glucose utilization throughout the body. The effect of these changes in metabolism is reflected in a decrease in fat mass and an increase in fat free mass, as shown in several studies (Vaisman et al 1994 , 1992 ; Gregory et al 1991 , 1993 ; Ernst et al 2012 ; Khadilkar et al 2014 ; Walker et al 1990 ; Boot et al 1997 ; Hassan et al 1996 ).…”

“…Eighty percent of the children with a good growth response (increase in height SDS > 0.7) had a change in TBW/height 2 exceeding the 2 SD reference line of the control group. Additionally, Ernst et al ( 2012 ) showed that the change in TBW after 6 weeks of GH treatment correctly predicted the growth response after the first year in 75% of GHD patients ( n = 88). For children born SGA ( n = 99), a change in TBW of > 0.7 L/m 2 was strongly predictive for a good growth response, but the negative predictive value was low (30%).…”