van Bakel M M, Printzen G, Wermuth B, Wiesmann U N
University Hospital, Children's Clinic, Division of Metabolic Diseases, and the Chemical Central Laboratory, University of Bern, Bern, Switzerland.
Am J Clin Nutr. 2000 Oct;72(4):976-81. doi: 10.1093/ajcn/72.4.976.
Subjects consuming protein-restricted diets, such as patients with phenylketonuria (PKU) or milder hyperphenylalaninemias (HPAs) are at risk of selenium deficiency. Selenium is a cofactor of the antioxidant enzyme glutathione peroxidase and of the thyroid hormone converting enzyme thyroxine deiodinase.
Our goal was to investigate the effects of low plasma selenium on antioxidant and thyroid hormone status.
We assessed plasma selenium, plasma total antioxidant status and the individual components thereof, erythrocyte antioxidant status, and plasma thyroid hormones in 24 PKU and 10 HPA patients and in 42 age-matched control subjects.
Selenium was significantly lower in both PKU and HPA patients than in control subjects and the PKU patients had lower values than did the HPA patients. Total antioxidant status was lower in both patient groups than in the control group, whereas alpha-tocopherol, albumin, and uric acid were not significantly different among groups. Plasma selenium correlated well (r = 0.76) with erythrocyte glutathione peroxidase. PKU patients had lower glutathione peroxidase activity than did HPA patients and control subjects and lower glutathione concentrations than did control subjects. Both patient groups had lower superoxide dismutase activity than did control subjects. Free triiodothyronine was higher in both patient groups than in control subjects, whereas free thyroxine was higher in the PKU patients only. Free thyroxine and reverse triiodothyronine were inversely correlated with selenium.
Supplementation with selenium seems to be advisable for patients consuming diets low in natural protein.
食用蛋白质限制饮食的人群，如苯丙酮尿症（PKU）患者或轻度高苯丙氨酸血症（HPA）患者，有缺硒风险。硒是抗氧化酶谷胱甘肽过氧化物酶和甲状腺激素转化酶甲状腺素脱碘酶的辅助因子。
我们的目标是研究低血浆硒对抗氧化和甲状腺激素状态的影响。
我们评估了24例PKU患者、10例HPA患者以及42例年龄匹配的对照者的血浆硒、血浆总抗氧化状态及其各个成分、红细胞抗氧化状态和血浆甲状腺激素。
PKU患者和HPA患者的硒水平均显著低于对照者，且PKU患者的值低于HPA患者。两组患者的总抗氧化状态均低于对照组，而α-生育酚、白蛋白和尿酸在各组之间无显著差异。血浆硒与红细胞谷胱甘肽过氧化物酶相关性良好（r = 0.76）。PKU患者的谷胱甘肽过氧化物酶活性低于HPA患者和对照者，谷胱甘肽浓度低于对照者。两组患者的超氧化物歧化酶活性均低于对照者。两组患者的游离三碘甲状腺原氨酸均高于对照者，而仅PKU患者的游离甲状腺素较高。游离甲状腺素和反三碘甲状腺原氨酸与硒呈负相关。
对于食用天然蛋白质含量低的饮食的患者，补充硒似乎是可取的。
