PHYSIOLOGY OF AGING

生理系统年龄变化的研究包括肾脏， 心血管和代谢领域。 特别值得注意的是， 饮食中营养素摄入与生理的关系。 这些包括蛋白质摄入对肾脏的影响， 功能（肌酐清除率），钙和蛋白质的影响 膳食纤维摄入量对骨质流失的影响，以及膳食纤维摄入量对 心血管危险因素。 蛋白质摄入量和钙摄入量的影响不同 这些理论化的。 因此，高蛋白质摄入量没有影响 同时对肾功能也没有任何影响， 在饮食估计后至少10年测量肾功能） 与骨矿物质没有关系（根据X线片估计， 皮质骨的厚度），或者与饮食同时， 测量或至少10年后。 纤维估计为 与心脏病的某些危险因素（血压， 甘油三酯和空腹血糖）（见代谢章节）。 接受葡萄糖治疗的雌性动物的两小时葡萄糖水平 耐力测验与记忆心理测验无相关性， 词汇量或反应时间，但与 认知能力测试（概念问题 解决）。 平均血压值与下降率无关， 对254例正常男性的肾功能进行了研究， 正常范围 当高血压被包括在内时， 在分析中， 与肾功能的快速丧失有关。

Studies of age changes in physiologic systems have included renal, cardiovascular, and metabolic areas. Of particular interest, has ben the relationship of dietary intake of nutrients to physiology. These have included the effects of protein intake on renal function (creatinine clearance), the effect of calcium and protein intake on bone loss, and the effect of dietary fiber intake on cardiovascular risk factors. The effects of both protein intake and calcium intake differed form those theorized. Thus, higher protein intake had no effect on simultaneous renal function nor did it have any effect on kidney function measured at lease 10 years after diet estimates) had no relationship to bone mineral (estimated on X-ray by the thickness of cortical bone) either at the same time as the dietary measurements or at least 10 years later. Fiber estimates were related to certain risk factors for cardiac disease (blood pressure, triglyceride and fasting pasma glucose) (see Metabolism Section). The two hour glucose levels of females undergoing glucose tolerance test was not related to psychological test of memory, vocabulary, or reaction time but were significantly related to performance on a test of cognitive ability (conceptual problem solving.) Mean blood pressure values were not related to the rate to fall in renal function in 254 normal men with blood pressures in the normal range. When higher levels of blood pressure were included in the analysis there was a relationship with higher pressures being associated with more rapid loss of renal function.