Yassine Hussein, Kimzey Michael J, Galligan Michael A, Gandolfi A Jay, Stump Craig S, Lau Serrine S
Section of Endocrinology, Diabetes and Hypertension, Department of Medicine, College of Medicine, Southern Arizona Veterans Administration Healthcare System, University of Arizona, Ariz., USA.
Cardiorenal Med. 2012 Feb;2(1):26-32. doi: 10.1159/000334225. Epub 2011 Dec 23.
BACKGROUND/AIMS: Arsenic (As) is linked to insulin resistance in animal studies, but the effect of low-level As exposure on the prevalence of diabetes in humans is uncertain. An optimal method to report inorganic As in humans has not been established. Measurements of As in spot urine are usually adjusted to creatinine (Cr). However, urinary Cr is an independent variable in diabetes. Our aims are to optimize reporting of urinary As in the setting of diabetes and insulin resistance. METHODS: Urinary inorganic As was measured in 24-hour or first-void spot urine from diabetic (n = 31) and non-diabetic (n = 12) subjects and normalized to Cr or specific gravity (SG). The relation of normalized urinary inorganic As to glycemia and surrogate measures of insulin resistance was investigated. Blood pressure, waist circumference, and glycated hemoglobin were also assessed. Homeostasis model assessment was used to determine insulin resistance. RESULTS: A strong correlation was found between spot urinary As adjusted to Cr (R(2) = 0.82) or SG (R(2) = 0.61) to 24-hour urinary As (p < 0.001), while non-adjusted urinary As did not correlate well (R(2) = 0.03, p = 0.46). Adjusting for Cr revealed significant differences in total 24-hour urinary As when comparing diabetic to normal subjects. In contrast, no differences were found when As was adjusted to SG using either 24-hour or spot urine. Moreover, adjusted urinary spot or 24-hour As measures did not correlate with measures of glycemia or insulin resistance. Conclusions: Urinary Cr is an independent variable in diabetes, therefore adjusting spot As for SG is preferred.
背景/目的：在动物研究中，砷（As）与胰岛素抵抗有关，但低水平砷暴露对人类糖尿病患病率的影响尚不确定。目前尚未建立一种在人体中报告无机砷的最佳方法。随机尿中砷的测量通常会根据肌酐（Cr）进行调整。然而，尿肌酐是糖尿病中的一个独立变量。我们的目的是在糖尿病和胰岛素抵抗的背景下优化尿砷的报告。方法：测量了糖尿病患者（n = 31）和非糖尿病患者（n = 12）24小时或首次晨尿中的尿无机砷，并将其标准化为肌酐或比重（SG）。研究了标准化尿无机砷与血糖及胰岛素抵抗替代指标之间的关系。还评估了血压、腰围和糖化血红蛋白。采用稳态模型评估来确定胰岛素抵抗。结果：发现根据肌酐（R² = 0.82）或比重（R² = 0.61）调整后的随机尿砷与24小时尿砷之间存在强相关性（p < 0.001），而未调整的尿砷相关性不佳（R² = 0.03，p = 0.46）。在比较糖尿病患者与正常受试者时，根据肌酐调整后发现24小时尿总砷存在显著差异。相比之下，当使用24小时尿或随机尿将砷调整为比重时，未发现差异。此外，调整后的随机尿或24小时尿砷测量值与血糖或胰岛素抵抗指标无关。结论：尿肌酐是糖尿病中的一个独立变量，因此将随机尿砷根据比重进行调整更为可取。
