Advia 1800 auto analyzer

From eight-hours fasting serum, total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDLC) and low-density lipoprotein cholesterol (LDLC) levels were analyzed enzymatically with an ADVIA 1800 AutoAnalyzer (Siemens Medical Sol.). In this analysis, we presented the distribution of TG in its logarithmic form due to skewed distribution. Dyslipidemia was defined based on the 2018 Korean Dyslipidemia Treatment Guideline [19 (link)], which is equivalent to the Adult Treatment Panel III guidelines [20 (link)]. Hypercholesterolemia was defined as TC ≥240 mg/dL; hypertriglyceridemia was defined as TG ≥200 mg/dL; hypoalphalipoproteinemia was defined as HDLC < 40 mg/dL; hyper-LDL-cholesterolemia was defined as LDLC ≥160 mg/dL. Having any one type of the aforementioned cholesterol abnormality or current intake of lipid-lowering agent was regarded as prevalent dyslipidemia.

An overnight-fasting 10 mL blood sample from each participant was collected and immediately centrifuged (3000× g, 10 min). Serum fasting glucose, glycated hemoglobin (HbA1c), total cholesterol, triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), blood urea nitrogen (BUN), creatinine, and C-reactive protein (CRP) levels were measured using a Siemens Advia 1800 autoanalyzer (Siemens Healthcare GmbH, Henkestr, Germany) [13 (link),22 (link),23 (link)]. In a random spot urine sample, we tested urine albumin–creatinine ratio (UACR). We measured serum A-FABP concentrations via commercially available enzyme immunoassay kits (SPI-BIO, Montigny-le-Bretonneux, France) [13 (link),22 (link)]. The intra- and inter-assay coefficients of variation were 6.6% and 5.1%, respectively. Using the Chronic Kidney Disease Epidemiological Collaboration (CKD-EPI) equation, the estimated glomerular filtration rate was calculated [24 (link)].

After an overnight fast, blood samples were obtained via venipuncture in the morning (8–9 a.m.). Hemoglobin levels were measured using a flow cytometry method (ADVIA 2120i, Siemens, USA). The normal ranges for hemoglobin level are 12–15.5 g/dL in women and 13–17.5 g/dL in men (Shah et al., 2011 (link)). Serum creatinine levels were measured using a colorimetry method (ADVIA 1800 Auto Analyzer, Siemens, USA). Serum folate and vitamin B₁₂ were measured using a radioimmunoassay method (Gamma-counter) with a vitamin B₁₂ [⁵⁷Co] / folate [¹²⁵I] radioassay kit. Additionally, genomic DNA was extracted from whole blood and apolipoprotein E (APOE) genotyping was performed as previously described (Wenham et al., 1991 (link)). APOE ε4 (APOE4) positivity was defined as the presence of at least one ε4 allele.

After an overnight fasting, blood samples were obtained via venipuncture in the morning (8–9 a.m.). We measured serum zinc and copper levels using an inductively coupled plasma-mass spectrometer (model 820-MS; Bruker, Australia). We also measured serum copper, calcium, iron, transferrin, and ceruloplasmin levels because they could confound the relationship between zinc levels and brain changes [21 (link)]. We measured blood hemoglobin, albumin, and total cholesterol levels to evaluate anemia and nutritional deficiency. Calcium, iron, albumin, and total cholesterol levels were measured using a colorimetric method (Advia 1800 Auto analyzer, Siemens, USA). Transferrin and ceruloplasmin were measured employing immunoturbidimetric assays (Cobas Integra 800, Roche Diagnostics). Albumin levels were automatically determined (Advia 1800; Siemens, USA). Hemoglobin levels were determined by flow cytometry (Advia 2120i; Siemens, USA). Genomic DNA was extracted from whole blood and apolipoprotein E (apoE) genotyping performed as previously described [22 (link)]. ApoE ε4 allele (APOE4) positivity was defined as the presence of at least one ε4 allele.

Inflammatory status was assessed using 8-hour fasting morning blood plasma samples. Plasma levels of hs-CRP were analyzed with a turbid immunoassay (ADVIA1800 Auto Analyzer; Siemens Medical Solutions, Malvern, PA, USA). According to the manufacturer, the detection range for the hs-CRP assay is 0.01 mg/L to 1,000 mg/L, with a sensitivity of 0.2 mg/L (men: median, 0.64; interquartile range, 0.40 to 1.36; women: median, 0.60; interquartile range, 0.34 to 1.18).