Renal Division, Stadtspital Waid Zurich, Zurich, Switzerland.
Clin J Am Soc Nephrol. 2012 Sep;7(9):1461-72. doi: 10.2215/CJN.01100112. Epub 2012 Jul 5.
Acidosis and transplantation are associated with increased risk of bone disturbances. This study aimed to assess bone morphology and metabolism in acidotic patients with a renal graft, and to ameliorate bone characteristics by restoration of acid/base homeostasis with potassium citrate.
This was a 12-month controlled, randomized, interventional trial that included 30 renal transplant patients with metabolic acidosis (S-[HCO(3)(-)] <24 mmol/L) undergoing treatment with either potassium citrate to maintain S-[HCO(3)(-)] >24 mmol/L, or potassium chloride (control group). Iliac crest bone biopsies and dual-energy X-ray absorptiometry were performed at baseline and after 12 months of treatment. Bone biopsies were analyzed by in vitro micro-computed tomography and histomorphometry, including tetracycline double labeling. Serum biomarkers of bone turnover were measured at baseline and study end. Twenty-three healthy participants with normal kidney function comprised the reference group.
Administration of potassium citrate resulted in persisting normalization of S-[HCO(3)(-)] versus potassium chloride. At 12 months, bone surface, connectivity density, cortical thickness, and cortical porosity were better preserved with potassium citrate than with potassium chloride, respectively. Serological biomarkers and bone tetracycline labeling indicate higher bone turnover with potassium citrate versus potassium chloride. In contrast, no relevant changes in bone mineral density were detected by dual-energy X-ray absorptiometry.
Treatment with potassium citrate in renal transplant patients is efficient and well tolerated for correction of metabolic acidosis and may be associated with improvement in bone quality. This study is limited by the heterogeneity of the investigated population with regard to age, sex, and transplant vintage.
酸中毒和移植与骨紊乱风险增加有关。本研究旨在评估伴有肾移植的酸中毒患者的骨形态和代谢，并通过使用柠檬酸钾恢复酸碱平衡来改善骨特征。
这是一项为期 12 个月的对照、随机、干预性试验，纳入了 30 例代谢性酸中毒（S-[HCO3(-)]<24mmol/L）的肾移植患者，分别接受柠檬酸钾治疗（以维持 S-[HCO3(-)]>24mmol/L）或氯化钾（对照组）治疗。在基线和治疗 12 个月时进行髂嵴骨活检和双能 X 射线吸收法检查。通过体外微计算机断层扫描和组织形态计量学分析，包括四环素双标记法分析骨活检。在基线和研究结束时测量血清骨转换标志物。23 例肾功能正常的健康参与者组成参考组。
柠檬酸钾组 S-[HCO3(-)]持续正常化，而氯化钾组则没有。12 个月时，与氯化钾组相比，柠檬酸钾组骨表面、连通密度、皮质厚度和皮质孔隙度分别得到更好的保留。血清生物标志物和骨四环素标记表明，与氯化钾组相比，柠檬酸钾组的骨转换更高。相比之下，双能 X 射线吸收法未检测到骨密度的相关变化。
在肾移植患者中，使用柠檬酸钾治疗代谢性酸中毒有效且耐受良好，可能与改善骨质量有关。本研究的局限性在于研究人群的年龄、性别和移植时间存在异质性。
