ersus external (e.g., dietary) factors to UA stone propensity is challenging due to uncontrolled diets in outpatients in previously published studies. Methods: This compilation of metabolic studies with body composition examined by dual-energy X-ray absorptiometry (DXA) scan, and blood and urine biochemistry collected under a controlled metabolic diet was conducted across three distinct populations: 74 UA stone formers (UASF group), 13 patients with type 2 diabetes mellitus without kidney stones (DM group), and 51 healthy volunteers (HV group). Results: Compared to HV, both UASF and DM exhibited higher levels of net acid excretion (NAE), and significantly lower urine pH and lower proportion of NAE excreted as ammonium (NH4+/NAE), all under controlled diets. UASF exhibited significantly lower NH4+/NAE compared with DM. UASFs also showed higher total body and truncal fat compared to controls. Among the HV, lower NH4+/NAE ratio correlated with higher truncal and total fat. However, this association was abolished in the UASF and DM groups who exhibit a fixed low NH4+/NAE ratio across a range of body and truncal fat. Conclusion: The findings suggest a dual defect of diet-independent increase in acid production and impaired kidney NH4+ excretion as major contributors to the risk for uric acid stone formation. There is an inverse physiologic association between body fat content and NH4+/NAE in HV while NH4+/NAE is persistently low in UASF and DM regardless of body fat representing pathophysiology. Copyright © 2024 by the American Society of Nephrology...

中文翻译：

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尿酸结石形成者和 2 型糖尿病患者的脂肪分布和尿石症风险参数


由于在先前发表的研究中门诊患者饮食不受控制，导致 UA 结石倾向的外部（例如饮食）因素具有挑战性。方法： 通过双能 X 射线吸收测定法 （DXA） 扫描检查身体成分，并在受控代谢饮食下收集血液和尿液生化的代谢研究汇编在三个不同的人群中进行：74 名 UA 结石形成者 （UASF 组），13 名无肾结石的 2 型糖尿病患者 （DM 组），和 51 名健康志愿者 （HV 组）。结果： 与 HV 相比，UASF 和 DM 均表现出更高水平的净酸排泄 （NAE），并且尿液 pH 值显著降低，以铵态氮 （NH4+/NAE） 形式排泄的 NAE 比例较低，所有这些都在受控饮食下。与 DM 相比，UASF 的 NH4 + /NAE 显著降低。与对照组相比，UASF 还表现出更高的全身脂肪和躯干脂肪。在 HV 中，较低的 NH4 + /NAE 比率与较高的躯干和总脂肪相关。然而，这种关联在 UASF 和 DM 组中被消除，他们在一系列身体和躯干脂肪中表现出固定的低 NH4+/NAE 比率。结论： 研究结果表明，与饮食无关的酸产生增加和肾脏 NH4+ 排泄受损的双重缺陷是尿酸结石形成风险的主要因素。HV 中的体脂含量与 NH4+/NAE 之间存在负生理关联，而 UASF 和 DM 中的 NH4+/NAE 持续较低，无论体脂代表病理生理学如何。美国肾脏病学会版权所有 © 2024...