Mitch W E
Division of Nephrology, Baylor College of Medicine, Houston, Texas, USA.
J Nephrol. 2006 Mar-Apr;19 Suppl 9:S70-5.
Acid-base balance is precisely regulated by pulmonary and renal responses while body buffers help to control pH. When its regulation becomes abnormal, accumulation of hydrogen ions cause metabolic acidosis and several responses are activated. These responses interfere with the metabolism of bones and muscle. Metabolic acidosis induces abnormalities in the release and function of several hormones including defects in growth hormone, IGF-1, insulin, glucocorticoids, thyroid hormone, parathyroid hormone and vitamin D. Clinical consequences of these abnormal metabolic responses include impaired growth of infants and children and loss of bone and muscle mass in adults. Notably, abnormalities in bone and muscle metabolism can be present even when there is little or no decrease in the plasma bicarbonate concentration. The abnormalities can be corrected by treatment with NaHCO 3 . In patients with chronic kidney disease, many abnormalities in bone and muscle metabolism can be directly linked to the presence of metabolic acidosis and these abnormalities can be largely corrected by treating acidosis with NaHCO3. Recent insights indicate that several consequences of metabolic acidosis including the development of insulin resistance can stimulate muscle protein degradation by activating proteolytic mechanisms. To avoid abnormalities in metabolism and the loss of bone and muscle, metabolic acidosis must be corrected in normal adults and in patients with kidney disease.
酸碱平衡由肺和肾的反应精确调节，而身体缓冲物质有助于控制pH值。当其调节变得异常时，氢离子的积累会导致代谢性酸中毒，并激活多种反应。这些反应会干扰骨骼和肌肉的代谢。代谢性酸中毒会导致多种激素的释放和功能异常，包括生长激素、胰岛素样生长因子-1、胰岛素、糖皮质激素、甲状腺激素、甲状旁腺激素和维生素D的缺陷。这些异常代谢反应的临床后果包括婴幼儿生长发育受损以及成年人骨量和肌肉量的流失。值得注意的是，即使血浆碳酸氢盐浓度几乎没有下降，骨骼和肌肉代谢也可能出现异常。用碳酸氢钠治疗可以纠正这些异常。在慢性肾病患者中，骨骼和肌肉代谢的许多异常可直接与代谢性酸中毒的存在相关，通过用碳酸氢钠治疗酸中毒，这些异常在很大程度上可以得到纠正。最近的研究表明，代谢性酸中毒的一些后果，包括胰岛素抵抗的发展，可通过激活蛋白水解机制刺激肌肉蛋白降解。为避免代谢异常以及骨骼和肌肉的流失，正常成年人和肾病患者的代谢性酸中毒都必须得到纠正。
