Objectives Nonalcoholic fatty liver disease (NAFLD) is one of the most common liver diseases in the pediatric population at global level. Present study aims to assess the effect of l -carnitine supplementation on the NAFLD in children and adolescents. Methods This randomized, triple-blind, placebo-controlled clinical trial was conducted in 2018–2019. Study was carried out in NAFLD participants (5–15 years). They were randomly assigned to receive either 50 mg/kg/day l -carnitine twice a day or identical placebo per day for three months. Liver enzymes and liver ultrasonography were assessed before and after the intervention. Both groups received similar consultation for lifestyle changes. Results Overall, 55 participants completed the study, 30 patients in the l -carnitine group and 25 patients in placebo group. Mean changes of anthropometric measurements did not have significant differences between groups (p>0.05). No significant differences in the mean changes of aspartate aminotransferase (AST) (p=0.82) and alanine aminotransferase (ALT) (p=0.76) levels were documented between two groups. Based on within-group analysis, there were significant changes in AST and ALT levels before and after the intervention in both groups. The sonographic grades of fatty liver were not significantly different between two groups before (p=0.94) and after intervention (p=0.93). Conclusions In the present clinical trial, L-carnitine did not have significant effect on improving biochemical and sonographic markers of NAFLD in children and adolescents. Future studies are necessary to evaluate the applicability and efficacy of long-term l -carnitine supplementation to treatment of NAFLD in pediatric population. Trial registration IRCT20170628034786N2.

中文翻译：

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左旋肉碱补充剂对非酒精性脂肪肝 (NAFLD) 儿童和青少年的影响：一项随机、三盲、安慰剂对照临床试验

目的 非酒精性脂肪性肝病 (NAFLD) 是全球儿科人群中最常见的肝脏疾病之一。本研究旨在评估补充左旋肉碱对儿童和青少年 NAFLD 的影响。方法 这项随机、三盲、安慰剂对照的临床试验于 2018-2019 年进行。研究是在 NAFLD 参与者（5-15 岁）中进行的。他们被随机分配接受每天两次 50 毫克/公斤/天的 l-肉碱或相同的安慰剂，持续三个月。在干预前后评估肝酶和肝脏超声检查。两组都接受了类似的生活方式改变咨询。结果 总体而言，55 名参与者完成了研究，其中左旋肉碱组 30 名患者和安慰剂组 25 名患者。人体测量的平均变化在组间没有显着差异（p>0.05）。两组间天冬氨酸转氨酶 (AST) (p=0.82) 和丙氨酸转氨酶 (ALT) (p=0.76) 水平的平均变化没有显着差异。组内分析显示，两组干预前后AST、ALT水平均有显着变化。两组脂肪肝超声分级在干预前（p=0.94）和干预后（p=0.93）无显着差异。结论 本次临床试验中，左旋肉碱对改善儿童和青少年NAFLD的生化和超声标志物无明显作用。未来的研究需要评估长期补充左旋肉碱治疗儿科 NAFLD 的适用性和有效性。试用注册IRCT20170628034786N2。