Comparative effect oftwodoses ofgrowth hormoneforgrowth hormonedeficiency

The comparative effectand safetyof 2 IU comparedwith4 IU/m2/dayof recombinanthuman growthhormone (rhGH)was studied in38growthhormone deficient children regarding theimpactof several factors on shortterm (oneyear) and longterm (threeyear)growth response. In21newlydiagnosed patients, three years ofrhGH treatmentresulted ina significant increase ofheight velocity SD score, heightSD score, and predicted adultheightSD score, irrespective of rhGH dose.In 17 transferpatients (previouslytreatedwith 12 IU rhGH/m2/week) 4IU/m2/day resulted ina significantly higherheightvelocity SD score and heightSD score forchronological age than 2 IU/m2/day, while more ofthemreachedtheirtargetrange or showed a substantial heightSD score increment. HeightSD score for boneage andpredicted adultheightSD score onlyincreased significantly with4 IUrhGH. Afterone year ofrhGH treatment, new patients showedsignificant negative correlation betweenA heightSD score withage andbaseline insulin-like growth factorI (IGF-I)SD score,andpositive correlation withrhGH dose.Afterthree yearsoftreatment, A height SD scorefor chronological age was significantly, negatively correlated withage andbaseline 'corrected' heightSD score (height SD score forchronological age minustarget heightSD score). Therewas no significant correlation with rhGH dose. Prolongedtreatmentwitheitherdose had no adverseeffecton IGF-I concentrations,carbohydrateor lipid metabolism. As earlyage and divergence between heightSD score and targetheight SD score seem more importantfor growthresponse thanrhGH dose,itis recommendedthattreatmentstartsearly with2 IU rhGH/m2/day and thedoseis doubledifgrowthisinsufficient after several yearsoftreatment. (Arch DisChild 1994; 71:12-18)