Baldwin Christine, Dewit Odile, Elia Marinos
Department of Medicine and Therapeutics, Imperial College, Chelsea & Westminster Hospital, Fulham Road, London SW10 9NH, UK.
Clin Nutr. 2004 Apr;23(2):249-55. doi: 10.1016/j.clnu.2003.07.003.
This study aimed to examine whether circulating concentrations of a range of vitamins and trace elements in patients receiving long-term cyclic enteral tube feeding vary during the day, and whether standardised time points for blood sampling are required for assessment of nutrient status.
Circulating concentrations or activities of water-soluble vitamins (thiamine, riboflavin, and vitamins B6, B12, folate and C), fat-soluble vitamins (A, D, E) and trace elements (iron, zinc, copper and selenium (assessed by glutathione peroxidase activity), were measured at 0,3,6 and 9-12h after cessation of nocturnal feeding (fasting), in eight clinically stable patients receiving cyclic nocturnal enteral nutrition.
The circulating concentrations of the nutrients did not change between the fed and fasted state (repeated-measures-ANOVA) except the following: plasma folate increased progressively from 10.9 (SD 4.6)nmol/l in the fed state to 14.0 (SD 4.4)nmol/l at 9-12 h after cessation of feeding (P<0.05); plasma zinc increased progressively throughout the fasting period by 33.5% (8.57, SD 0.68 vs. 11.44, SD 1.85 micromol/l, in fed state vs. 9-12h fast respectively, P<0.05); and total tocopherol/cholesterol ratio decreased by 9.6% during the study period (P<0.02), while gamma-tocopherol increased by 59.2% (P<0.05). For all analytes, the concentrations in blood samples taken at 3 and 6h after cessation of feeding were not significantly different from those at 9-12h.
Although cessation of nocturnal tube feeding had no significant effect on the circulating concentrations of most micronutrients, it increased plasma folate and zinc concentrations, and decreased the tocopherol/cholesterol ratio. The timing for blood sampling should be standardised when the status of these nutrients is assessed in patients receiving cyclic tube feeding.
本研究旨在探讨接受长期循环肠内管饲的患者体内一系列维生素和微量元素的循环浓度在一天中是否会发生变化，以及评估营养状况时是否需要标准化的采血时间点。
对8例接受夜间循环肠内营养且临床状况稳定的患者，在夜间喂养停止后（禁食状态）的0、3、6和9 - 12小时，测定水溶性维生素（硫胺素、核黄素、维生素B6、B12、叶酸和C）、脂溶性维生素（A、D、E）以及微量元素（铁、锌、铜和硒（通过谷胱甘肽过氧化物酶活性评估））的循环浓度或活性。
除以下情况外，进食和禁食状态下营养素的循环浓度无变化（重复测量方差分析）：血浆叶酸从进食状态下的10.9（标准差4.6）nmol/l逐渐升高至喂养停止后9 - 12小时的14.0（标准差4.4）nmol/l（P<0.05）；血浆锌在整个禁食期间逐渐升高33.5%（进食状态下为8.57，标准差0.68 μmol/l，禁食9 - 12小时时为11.44，标准差1.85 μmol/l，P<0.05）；研究期间总生育酚/胆固醇比值下降9.6%（P<0.02），而γ-生育酚升高59.2%（P<0.05）。对于所有分析物，喂养停止后3小时和6小时采集的血样浓度与9 - 12小时采集的血样浓度无显著差异。
尽管夜间管饲停止对大多数微量营养素的循环浓度无显著影响，但它增加了血浆叶酸和锌浓度，并降低了生育酚/胆固醇比值。在评估接受循环管饲患者的这些营养素状况时，采血时间应标准化。
