TWO YEAR AUXOLOGICAL RESULTS OF A GROWTH HORMONE (GH) DOSE-RESPONSE STUDY IN TURNER SYNDROME (TS)

Abstract

In a multicenter dose-response study, 68 girls with TS (Tanner stage B1), age 6.5 (2.3) yr (range 2.1-11.0 yr) were randomized into 3 groups according to CA and H-SDSCA: A (n=23) 4 IU hGH/m2 b.s. for 4 yr, B (n = 23) 1st yr 4 IU and 2nd-4th yr 6 IU/m2, C (n = 22) 1st yr 4 IU, 2nd yr 6 IU, 3rd and 4lh yr 8 IU/m2 (Norditropin11) daily s.c. We report auxological data [n = 67, drop out: 1×B) aftef 2 yr GH therapy, in which period B + C were evaluated as one group.METHODS: Standing height (H) was measured by the some observer (AvT). SD scores for CA were calculated using combined data of an untreated Dutch-Swedish Danish TS reference population. Bone age (BA) was determined according to TW2 RUS to assess the index of potential height (H·SDSBA) and according to G&P for final height (FH) prediction according to Bayley Pinneau. Values are expressed as mean (SD). compared wilh prrRx, p ≤0.001; ° change from preRx between groups, p≤0.02; change from yr 1 between groups, p-0.03.In the 1st and 2nd yr HV and H·SDSCA increased compared with preRx in both groups (p ≤ 0.001). 2nd yr HV and ΔH·SDSCA were higher for B + C than for A (p ≤ 0.002). PreRx BA and ΔBA in yr 1 and 2 were nor different between groups. It yr 2, a further increment of FM pred occured only in B + C (p=0.003). ΔH·SDSBA after 2 yr was different from preRx in both groups (p < 0.001), without difference between groups. Age at start of Rx was negatively correlated (p=0.01) with ΔH·SDSCA after 2 yr Rx in B + C (r = 0.31), but not with ΔBA.CONCLUSIONS: A GH dose increment after the 1st yr of Rx from 4 to 6 IU/m2 b.s./d results in a better growth response expressed as HV and ΔH·SDSCA as well as in a better FH pred alter the 2nd yr Rx. However, H·SDSBA did not improve more with the higher dose. Bone age appears not to be influenced by the dosage increment. Start of GH Rx at a younyer age might be favourable.