21天头低位(-6°)卧床对机体摄入营养状况和头发Zn、Ca、Fe、Cu含量的影响

The effects of 21 days of -6 headdown tilt bed rest on human food intake, nutritional status, and Zn, Ca, Fe, Cu level in hair

目的探讨模拟失重对机体摄入营养状况和头发Ｚｎ、Ｃａ、Ｆｅ、Ｃｕ含量的影响。方法受试者－６°头低位卧床２１天，用称量法观察其营养素摄入量变化，记录卧床第１天、１１天和第２１天的体重、尿量和上臂围，同时收集受试者头发，用原子火焰吸收分光光度法测定头发Ｚｎ、Ｃａ、Ｆｅ、Ｃｕ元素的含量。结果膳食Ｚｎ、Ｃａ、Ｆｅ、Ｃｕ在模拟失重第２周降低，第３周后基本恢复正常。头发中的含量第１１天较第１天显著下降（Ｐ＜０．０１），第２１天恢复原来水平。尿量增加，体重和上臂围无明显变化。结论模拟失重对机体摄入营养状况和头发Ｚｎ、Ｃａ、Ｆｅ、Ｃｕ含量有短期影响，经过适应期后可恢复到正常范围。

Objective To explore the effects of 3 weeks simulated weightlessness on human food intake, nutritional status and Zn, Ca, Fe, Cu levels in hair. Methods Eighteen healthy youngmen served as subjects. They underwent 3 weeks bed rest with head down tilt -6. The daily amount of food intake, amount of urine, upper arm circumference, body weight were recorded and levels of Zn, Ca, Fe, Cu in hair were measured during different period of the test. Results The total calories of food intake in the 2nd week was significantly lowered but restored to initial level in the 3rd week. Zn, Ca, Fe, Cu levels in hair at 11th day of the test were significantly lower than those measared at 1st day but restored to initial levels at 21st day. Body weight and circumference of upper arm did not show significant change during the 3 weeks test. The amount of urine at 11th day and 21st day was significantly higher than that at 1st day. Conclusions It is suggested that food intake and nutritional status of human body may be effected by simulated weightlessness, but return to normal after a period of adaptation.