Table 1_Transitioning of protein substitutes in patients with phenylketonuria: a pilot study.docx

IntroductionIn phenylketonuria (PKU), there is limited information about transitioning between protein substitutes and the influencing factors, particularly in young children. This pilot study assessed the stepwise transition from second to third-stage protein substitutes in children with PKU, aged 3–5 years.
MethodsDemographics, child behavior, maternal anxiety, and food neophobia scores were collected at baseline, mid-transition, and final assessment. Blood phenylalanine (Phe) was collected from 6 months pre-baseline to post-final assessment.
ResultsTwelve children (n = 4 males, 33%, median age 3.2 years) participated. Sixty-seven percent (n = 8) transitioned to liquid amino acid-based protein substitute and 33% (n = 4) to glycomacropeptide (cGMP) powder. Forty-two percent (n = 5/12) had a smooth transition (Group 1, median 3.5 months), while the remaining faced difficulty (n = 3, 25%, Group 2), or failed full transition (n = 4, 33%, Group 3). In Groups 2 and 3, caregivers failed to follow instructions, demonstrating inconsistencies and child resistance. Group 2 children had significantly higher blood Phe levels (above 360 μmol/L), that was significantly higher than Groups 1 and 3 (p < 0.01), with Groups 1 and 3 maintaining blood Phe within target (p < 0.01). Higher maternal education and nursery/school attendance significantly influenced transition success (p < 0.05). No significant differences were found in child neophobia, maternal anxiety, or child behavior (p > 0.05). Mothers generally reported satisfaction with the stepwise transition process.
ConclusionA stepwise transition to third-stage protein substitutes in PKU is effective, but is dependent on child metabolic control, parental education, and nursery/school support.

引言：苯丙酮尿症（phenylketonuria, PKU）患儿在不同阶段蛋白质替代剂之间的切换方案及其影响因素的相关研究资料较为匮乏，针对低龄儿童群体的相关研究尤为不足。本先导性研究针对3~5岁的PKU患儿，评估了其从第二代向第三代蛋白质替代剂的阶梯式切换流程。

研究方法：在基线期、切换中期及最终评估节点，收集受试者的人口学资料、儿童行为评分、母亲焦虑评分及食物新恐惧症评分。在基线前6个月至最终评估后阶段，采集患儿的血苯丙氨酸（phenylalanine, Phe）样本进行检测。

研究结果：本研究共纳入12名患儿，其中男性4名（占比33%），中位年龄3.2岁。67%的患儿（n=8）切换为液态氨基酸类蛋白质替代剂，33%的患儿（n=4）切换为糖巨肽（glycomacropeptide, cGMP）粉剂。42%的患儿（n=5/12）切换过程顺利（第1组，中位切换时长3.5个月）；剩余患儿中，3名（25%，第2组）出现切换困难，4名（33%，第3组）未能完成完整切换。第2、3组的照护者均未遵循操作指导，表现为执行流程不一致且患儿存在抗拒行为。第2组患儿的血苯丙氨酸水平显著高于第1、3组（均高于360 μmol/L，p<0.01），而第1、3组患儿的血苯丙氨酸均维持在目标范围内（p<0.01）。母亲受教育程度较高及患儿入托/入学情况与切换成功显著相关（p<0.05）。各组患儿的食物新恐惧症评分、母亲焦虑评分及儿童行为评分均无显著差异（p>0.05）。多数母亲表示对阶梯式切换流程较为满意。

研究结论：针对PKU患儿的第三代蛋白质替代剂阶梯式切换方案具备有效性，但其实施效果依赖于患儿的代谢控制水平、家长受教育程度以及托育/学校的支持配合。