Department of Epidemiology and the Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
Department of Pathology, University of Maryland School of Medicine, Baltimore, MD, USA.
J Appl Lab Med. 2022 Jun 30;7(4):916-922. doi: 10.1093/jalm/jfab168.
Glycated albumin is cleared by the Food and Drug Administration (FDA) for clinical use in diabetes care. To understand its performance in the general US population, we conducted measurements in >19 000 samples from the National Health and Nutrition Examination Survey (NHANES). Of these samples, 5.7% had previously undergone at least 2 freeze-thaw cycles and were considered "non-pristine."
We measured glycated albumin and albumin using the Lucica GA-L (Asahi Kasei) assay in stored serum samples from NHANES 1999-2004. Serum albumin (Roche/Beckman) was previously measured. We examined the correlations of percent glycated albumin with hemoglobin A1C (HbA1c)and fasting glucose in the pristine and non-pristine samples. We also measured cystatin C (Siemens) and compared these to cystatin C (Dade Behring) previously obtained in a subsample.
Glycated albumin (%) was significantly lower in pristine vs non-pristine samples (13.8% vs 23.4%, P < 0.0001). The results from the Asahi Kasei albumin assay (g/dL) were highly correlated with albumin originally measured in NHANES (Pearson's correlation coefficient, r = 0.76) but values were systematically higher (+0.25 g/dL, P < 0.0001). Cystatin C (Siemens) was similar to previous cystatin C measurements (r = 0.98) and did not differ by pristine status (P = 0.119). Glycated albumin (%) was highly correlated with HbA1c and fasting glucose in pristine samples (r = 0.78 and r = 0.71, respectively) but not in non-pristine samples (r = 0.11 and r = 0.12, respectively).
The performance of the glycated albumin assay in the pristine samples was excellent. Performance in non-pristine samples was highly problematic. Analyses of glycated albumin in NHANES 1999-2004 should be limited to pristine samples only. These results have major implications for the use of these public data.
糖化白蛋白已通过美国食品药品监督管理局（FDA）批准用于糖尿病治疗的临床应用。为了了解其在普通美国人群中的表现，我们在来自国家健康和营养检查调查（NHANES）的 19000 多个样本中进行了测量。这些样本中，有 5.7%的样本至少经历过 2 次冻融循环，被认为是“非原始样本”。
我们使用 Lucica GA-L（旭化成）试剂盒在 NHANES 1999-2004 年的储存血清样本中测量糖化白蛋白和白蛋白。此前已测量血清白蛋白（罗氏/贝克曼）。我们检查了原始样本和非原始样本中糖化白蛋白百分比与糖化血红蛋白（HbA1c）和空腹血糖的相关性。我们还测量了胱抑素 C（西门子），并将其与之前在亚样本中获得的 Dade Behring 胱抑素 C 进行了比较。
原始样本中的糖化白蛋白（%）明显低于非原始样本（13.8%比 23.4%，P <0.0001）。旭化成白蛋白测定法（g/dL）的结果与 NHANES 中最初测量的白蛋白高度相关（Pearson 相关系数，r = 0.76），但值系统偏高（+0.25 g/dL，P <0.0001）。胱抑素 C（西门子）与之前的胱抑素 C 测量值相似（r = 0.98），且不受原始状态的影响（P = 0.119）。原始样本中糖化白蛋白（%）与 HbA1c 和空腹血糖高度相关（r = 0.78 和 r = 0.71），而非原始样本中则无相关性（r = 0.11 和 r = 0.12）。
原始样本中糖化白蛋白测定法的性能非常出色。非原始样本中的性能存在严重问题。NHANES 1999-2004 中糖化白蛋白的分析应仅限于原始样本。这些结果对这些公共数据的使用具有重大影响。
