Sailer Melissa, Elizondo Gabriela, Martin Julie, Harding Cary O, Gillingham Melanie B
Graduate Programs in Human Nutrition at Oregon Health & Science University, Portland, OR, United States of America.
Departments Molecular and Medical Genetics, Graduate Programs in Human Nutrition at Oregon Health & Science University, Portland, OR, United States of America.
Mol Genet Metab Rep. 2020 May 11;23:100599. doi: 10.1016/j.ymgmr.2020.100599. eCollection 2020 Jun.
Phenylketonuria (PKU) treatment consists of life-long protein restriction and Phe-free medical foods for adequate nutritional intake and growth. A relationship between body composition and blood phenylalanine (Phe) concentrations in subjects with PKU has been proposed but this has not been consistently reported.
Dietary intake, lean body mass (LBM) and fat mass (FM) were measured in 30 pediatric subjects with PKU compared to 30 age, and sex matched controls. The relationship between body composition and blood Phe was analyzed within the PKU cohort from clinically collected dried blood spot Phe concentrations.
Male subjects with PKU had less LBM% and more FM% than controls ( = .024). There was no difference in LBM% and FM% among female subjects. Age ( = .02) and FM% (p = .02) were positively correlated to dried blood spot Phe. Synthetic protein intake (g/kg body weight) was negatively correlated with dried blood spot Phe ( = .04). Natural protein intake was not related to blood spot Phe.
Children with PKU face additional dietary challenges maintaining healthy growth and body composition while keeping Phe levels low. We observed higher FM% and lower LBM% in male subjects with PKU. Correlations do not prove cause and effect but suggest a relationship between increased blood Phe, lower synthetic protein intake and increased FM%. Future studies may explore if lower blood Phe concentrations is associated with a lower FM% and higher LBM%; particularly among adult patients now managed on pegvaliase (Palynziq®) who consume normal amounts of natural protein or among younger patients who consume glycomacropeptide (GMP).
苯丙酮尿症（PKU）的治疗包括终身蛋白质限制以及食用不含苯丙氨酸（Phe）的医用食品，以确保充足的营养摄入和生长。有人提出PKU患者的身体成分与血液苯丙氨酸（Phe）浓度之间存在关联，但这一关联尚未得到一致报道。
对30名患有PKU的儿科患者进行饮食摄入量、瘦体重（LBM）和脂肪量（FM）的测量，并与30名年龄和性别匹配的对照组进行比较。根据临床收集的干血斑Phe浓度，分析PKU队列中身体成分与血液Phe之间的关系。
患有PKU的男性受试者的LBM%低于对照组，FM%高于对照组（P = 0.024）。女性受试者的LBM%和FM%没有差异。年龄（P = 0.02）和FM%（P = 0.02）与干血斑Phe呈正相关。合成蛋白质摄入量（克/千克体重）与干血斑Phe呈负相关（P = 0.04）。天然蛋白质摄入量与血斑Phe无关。
PKU患儿在保持低Phe水平的同时，在维持健康生长和身体成分方面面临额外的饮食挑战。我们观察到患有PKU的男性受试者FM%较高，LBM%较低。相关性并不证明因果关系，但提示血液Phe升高、合成蛋白质摄入量降低和FM%增加之间存在关联。未来的研究可以探讨较低的血液Phe浓度是否与较低的FM%和较高的LBM%相关；特别是在目前使用培格洛酶（Palynziq®）治疗且摄入正常量天然蛋白质的成年患者中，或者在摄入糖巨肽（GMP）的年轻患者中。
