大豆蛋白質對慢性腎衰竭患者血壓、血脂與腎功能的影響
Effect of soy protein on blood pressure, lipid metabolism and renal function in chronic renal failure
中文摘要
慢性腎衰竭與透析患者心血管疾病罹患率高於一般人 10-20 倍，且其死亡率亦以 心血管疾病為首位。血壓是影響腎衰竭進展的重要因素，血脂異常為心血管疾病 的危險因子亦會加速腎衰竭的進行。研究顯示，大豆蛋白質能顯著改善一般高脂 血症患者的血脂異常、降低高血壓患者的血壓與延緩腎衰竭動物疾病進展。本研 究以隨機、雙盲、安慰劑對照控制的臨床試驗方式，以 30 克大豆蛋白或奶蛋白 等量取代飲食中動物性蛋白質 12 週，探討大豆蛋白質對血液透析患者血脂代謝 的影響。並以切除大白鼠 5/6 腎臟之慢性腎衰竭動物模式，評估大豆蛋白質胃蛋 白?水解物對慢性腎衰竭動物血壓調節、血脂代謝與腎功能的影響，探討大豆蛋 白質延緩腎衰竭的可能成分與機制。結果顯示：大豆蛋白質顯著降低高脂血症及 高膽固醇血症血液透析患者的血清總膽固醇、LDL-C、 non-HDL-C、
TC/HDL-C、apo B 與胰島素濃度，但對血脂正常的血液透析患者血清膽固醇與 脂蛋白濃度沒有影響。大豆白質亦降低血清總膽固醇與三酸甘油酯濃度皆過高的 高脂血症透析患者的血清三酸甘油酯並增加 HDL-C 濃度，但不影響血清三酸甘 油酯濃度正常的高膽固醇血症患者的血清三酸甘油酯與 HDL-C 濃度。此外，脂 蛋白電泳結果顯示，大豆蛋白質對高脂血症與高膽固醇血症透析患者脂蛋白組成 比例的改變不同，但皆有正常化脂蛋白組成的影響。大豆蛋白質經胃蛋白?水解 後的產物，分別在血壓調節與血脂代謝上有特殊影響。水解物經離心後的水溶性 上清液在降低血壓、血脂及延緩腎衰竭進展的效果上皆最顯著，離心後的大分子 沉澱物則顯著增加糞便膽酸及膽固醇的排出。結論：以大豆蛋白質等量取代飲食 中的動物性蛋白質對改善血液透析患者的血脂異常有極正面的影響，應可作為治 療血液透析患者血脂異常的飲食建議。大豆蛋白質胃蛋白?水解物經離心後的上 清液降壓效果最強，所以顯著延緩腎衰竭進展，進而改善血脂異常，應含有大豆 蛋白質影響腎衰竭進展最重要的成分。離心後非水溶性的沉澱部分顯著增加糞便 膽固醇的排出，能增加膽固醇代謝，降低血清膽固醇，是協助延緩腎衰竭進展的 成分。
英文摘要
Hyperlipidemic factors contribute to the high cardiovascular risk in hemodialysis patients and may accelerate the progression of renal disease. Soy protein has been shown to reduce some atherogenic lipid concentrations in subjects with normal renal function, and slow progression of renal injury, reduce blood pressure in experimental animals and human subjects. The mechanism and components of soy responsible have
not been fully established. The objectives of this study were to 1) evaluate the effect of soy protein on serum lipid profiles and lipoprotein metabolism in hyperlipidemic and normolipidemic hemodialysis patients. 2) investigate the effect of the two fractions of soy protein hydrolysate on renal function, blood pressure and lipid
metabolism in five-sixths nephrectomized rats, and to examine the active components of soy protein hydrolysate on ameliorating disease progression. Hyperlipidemic and normolipidemic hemodialysis patients were enrolled in a randomized, double-blind, placebo-controlled clinical trial. Thirty grams of isolated soy protein or milk protein was consumed daily as a beverage at breakfast or postdialysis for 12 wk.
Experimental animals were subjected to a nephrectomy and were fed two fractions isolated from soy protein hydrolysate prepared by peptic hydrolysis for 13 wk.
Results showed soy protein substitution significantly reduced total cholesterol, triglyceride, low-density lipoprotein cholesterol and apolipoprotein B concentrations, and the HDL-cholesterol was significantly increased in hyperlipidemic subjects.
There were no significant changes in serum lipid and lipoprotein concentrations in normolipidemic subjects. Both soy protein hydrolysate fractions favorably affected chronic renal failure. The supernatant fraction of soy protein hydrolysate had the most-significant decreases in blood pressure and significantly retarded progression of the experimentally induced renal disease. The precipitate fraction of soy protein hydrolysate exhibited significantly increased fecal excretion of total cholesterol. In conclusion, our findings demonstrate that replacing a part of the daily protein with soy protein could be used in the nutritional management of moderately hyperlipidemic hemodialysis patients. The supernatant fraction of soy protein hydrolysate had most-pronounced effect on slowing the progression of renal disease, and the
precipitate fraction of soy protein hydrolysate had a protective effect on renal function resulting from lowering cholesterol.
Key words：soy protein, hemodialysis, hyperlipidemia, soy protein hydrolysate, renal failure, cholesterol, blood pressure
