ESPE Abstracts

Background: GH treatment increases glomerular filtration rate (GFR), as serum IGF-I stimulates the renin-angiotensin system. Data on longitudinal changes in GFR after cessation of GH treatment in young adults born small for gestational age (SGA) are not available. It is essential to ascertain longitudinal data after cessation of GH treatment, to evaluate the possible long-term effects of higher serum IGF-I levels during childhood treatment on adult GFR.

Method: Longitudinal study in 230 young adults born SGA, previously treated with GH (SGA-GH). Serum creatinine levels were determined at cessation of GH treatment and at 6 months, 2 and 5 years thereafter. Data at 5 years after cessation of GH were compared with untreated age-matched controls (untreated short subjects born SGA (SGA-S), subjects born SGA with spontaneous catch-up growth (SGA-CU), subjects born appropriate for gestational age (AGA)).

Results: After correction for age, GFR decreased significantly during the first 6 months after cessation of GH treatment, while remaining well within the normal range (124.6 vs. 120.2mL/min/1.73m², P<0.001). GFR did not change between 2- and 5 years. GFR at 5 years after GH cessation was compared to that of 56 age-matched SGA-S, 118 SGA-CU and 135 AGA young adults. SGA-GH adults had a similar GFR as the untreated SGA-S and AGA adults, but GFR was lower compared to SGA-CU (108.7 vs. 119.6 mL/min/1.73m², resp., P=0.02).

Conclusion: In conclusion, our 5 years longitudinal follow-up study shows a decrease in GFR during 6 months after GH cessation, but GFR remained stable and within the normal range. GFR at 21 years of age was similar in GH-treated young adults born SGA and the untreated SGA-S and AGA young adults. We, therefore, conclude that long-term GH treatment in children born SGA has no unfavourable effects on kidney function in early adulthood.