Shakiba Marjan, Alaei Mohammadreza, Saneifard Hedyeh, Mosallanejad Asieh
Department of Pediatric Endocrinology and Metabolic diseases, Mofid children hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Iran J Child Neurol. 2020 Spring;14(2):27-39.
Dietary phenylalanine restriction is the main treatment of phenylketonuria (PKU, OMIM 261600). There are a number of studies which have demonstrated growth retardation in these patients, and some are in contrast. This study was performed to assess the growth parameters of treated PKU patients.
MATERIALS & METHODS: This cross-sectional study was performed between 2015 and 2017 to compare growth indices in PKU patients in our clinics with normal age and sex matched controls. Weight, height, head circumference (HC), weight for height and BMI (weight/height) were measured and converted into Z-scores. We assessed differences between patients and controls' anthropometric indexes in all patients and separately in patients who were diagnosed by newborn screening program and patients who were diagnosed after presentation of clinical manifestations in comparison with age and sex-matched controls. Also, this difference was assessed separately in patients aged two years and less. Correlations between pretreatment plasma phenylalanine concentrations mean plasma phenylalanine concentrations and anthropometric parameters were analyzed in the patients.
Overall 209 under-treatment PKU patients (103 males, 106 females; mean age 9.29 ± 8.7 years) and 216 controls (109 males and 107 females; mean age 8.98 ± 8.62 years) matched in terms of age, sex and birth weight were enrolled in this study. In general, 130 patients were diagnosed by newborn screening and 79 were diagnosed when they became symptomatic before the screening program. A significant difference (p=0.000) was found only in HC z-score and weight for height z-score in comparison with the control group, when we assessed all patients. We did not find any significant differences in any of the anthropometric indexes between cases and controls who were aged 2 years old and less. Head circumference SDS and weight for height SDS were significantly different when patients and controls who were more than 2 years old were compared. Mean HC was significantly lower in patients, while BMI SDS, weight SDS, and weight for height SDS were significantly higher in PKU patients in comparison with the control group when patients who were diagnosed in newborn screening were assessed. Head circumference SDS, BMI, height SDS and difference between patients' height SDS and mid parental height SDS had significantly lower mean scores in comparison with those of the control group, while mean weight SDS was significantly higher compared to controls when patients who were diagnosed after clinical presentation were assessed. Mean phenylalanine was not correlated with anthropometric indices, while there was a correlation between pretreatment phenylalanine and HC.
Disparities in anthropometric indexes changes observed in different studies may be due to diverse diet protocols, availability of various specific products and micronutrient substitutes.
饮食中限制苯丙氨酸是苯丙酮尿症（PKU，OMIM 261600）的主要治疗方法。有多项研究表明这些患者存在生长发育迟缓，也有一些研究结果相反。本研究旨在评估接受治疗的PKU患者的生长参数。
本横断面研究于2015年至2017年进行，以比较我们诊所中PKU患者与年龄和性别匹配的正常对照的生长指标。测量体重、身高、头围（HC）、身高体重比和BMI（体重/身高）并转换为Z评分。我们评估了所有患者以及分别通过新生儿筛查项目诊断的患者和出现临床表现后诊断的患者与年龄和性别匹配的对照之间人体测量指标的差异。此外，还对2岁及以下的患者进行了单独评估。分析了患者治疗前血浆苯丙氨酸浓度、平均血浆苯丙氨酸浓度与人体测量参数之间的相关性。
本研究共纳入209例未治疗的PKU患者（男103例，女106例；平均年龄9.29±8.7岁）和216例对照（男109例，女107例；平均年龄8.98±8.62岁），两组在年龄、性别和出生体重方面相匹配。总体而言，130例患者通过新生儿筛查确诊，79例在筛查项目前出现症状时确诊。在评估所有患者时，与对照组相比，仅在HC Z评分和身高体重比Z评分中发现显著差异（p = 0.000）。我们未发现2岁及以下病例与对照之间的任何人体测量指标存在显著差异。比较2岁以上患者与对照时，头围SDS和身高体重比SDS存在显著差异。在评估通过新生儿筛查确诊的患者时，与对照组相比，患者的平均HC显著较低，而PKU患者的BMI SDS、体重SDS和身高体重比SDS显著较高。在评估出现临床表现后确诊的患者时，与对照组相比，头围SDS、BMI、身高SDS以及患者身高SDS与父母平均身高SDS之间的差异的平均得分显著较低，而平均体重SDS显著较高。平均苯丙氨酸与人体测量指标无相关性，而治疗前苯丙氨酸与HC之间存在相关性。
不同研究中观察到的人体测量指标变化差异可能归因于不同的饮食方案、各种特定产品和微量营养素替代品的可获得性。
