Bone mineral density and BH4 treatment C Fraga, MG Valle, R Enacan,A Chiesa

FRAGA C,; A CHIESA.; G. VALLE.; R. ENACAN

Rio de Janeiro

Congreso; 13th International Congress of Inborn Errors of Metabolism .; 2017

SOCIEDAD LATINOAMERICANA DE ERRORES CONGENITOS Y PESQUISA NEONATAL (SLEIMPN)

Background Bone Mineral density (BMD) is compromised in PKU patients. New therapeutic approaches might be beneficial for bone acquisition.Objective: To describe the changes in BMD in PKU patients under treatment with BH4.Patients and methods 14 well controlled PKU patients were studied. 6 of them (Group 1 ( G1) ) (5 boys) median(M) age 18.7 years(y) (range(R): 12.6-19.71) with a M phenylalanine ( phe ) tolerance of 500(R: 450-1000) mg/day had been treated with BH4 for a M period of 2.3 y (R:1.3-3.8) The other 8 patients ( Group 2 ( G2)) (5 boys) M age 18.1y (R: 14,5-19.8) with a M phe tolerance of 400 (300-1000) mg/day were always under conventional treatment (diet + protein substitute).In them ,a previous period of 4,2(R: 2.14-5.5years was evaluated . Initial and final data on protein intake. Protein composition, Phe and calcium intake were recorded . Initial and final data of Total and Lumbar spine (L2-L4) Bone mineral density (BMD) assessed by Lunar DXA and adjusted by bone age assessed by Greulich & Pyle were retrieved, expressed as SDS according to local normal references and analyzed. Also BMD changes between initial and final data were calculated for each group. Mann Whitney test was used for statistical analysis.Results, Both groups presented similar initial Total and Lumbar spine L2-4 BMD Although with a trend of lesser total and Lumbar spine BMD in G2. Total : G1: 0.5 ( -0.4 to 2.3)vs. G2 0.39(-1.62 to 0.63) Lumbar : G1: 0.03(-1.71 to 2.23) vs. G2 -1.17(-2.53 to0.07) (both p:0.08) During the studied period G1, , increased phe tolerance 3. 5 ±1.6 times, protein intake 3.2 ±1.4 times and calcium intake from foods reached 53±32% of RDI while G2 continued with the same intake pattern Final Total and L2-L4 BMD were not different between groups Total G1:0.26(-0.14 to 2.9)vs G2 -0.18(-1.69 to 0.68) P:0.10. Lumbar G1 0.45((-1.6 to 2.65) vs -0.13 (-3.4 to 1.18) p:0.41.Differences achieved in total and L2-L4 BMD by both groups during the studied period did not differ.δTotal G1:0.19(-0.61 to 0.61) vs. G2:0.06(-1.4 to 1.1) p Non significant δLumbar G1:0.41(-1.13 to 0.47) vs. G2:0.57(-1.9 to 2.3)p NSConclusions: we weren?t able to evidence improvements in BMD or significant changes in its acquisition inn an homogeneus group of well controlled moderate PKU patients, although those treated with BH4 changed the intake of protein, calcium and phe.