Automatic analyzer 7600 7600 210

Blood samples were collected from an antecubital vein following an 8 h fast and were subsequently processed and immediately refrigerated. The serum levels of fasting glucose, total cholesterol, high-density lipoprotein cholesterol (HDL-C), and triglycerides were measured using a Hitachi Automatic Analyzer 7600/7600-210 (Hitachi, Tokyo, Japan). Low-density lipoprotein cholesterol (LDL-C) was calculated using the Friedewald formula (LDL-C = total cholesterol − [HDL-C + (triglycerides/5)]). Triglycerides/5 was used for serum samples with triglyceride values of ≤400 mg/dL, whereas it was set as missing for samples with triglyceride levels >400 mg/dL [16 (link)]. Non-HDL-C was calculated as total cholesterol minus HDL-C [17 (link)]. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured by ultraviolet without pyridoxal-5′-phosphate method using commercially available kits (Pureauto S ALT, Daiichi Pure Chemicals, Tokyo, Japan).
The cut-off points for prediabetes were defined as fasting glucose levels between 100 and 125 mg/dL according to the American Diabetes Association guideline [18 (link)]. NAFLD was defined as elevated ALT (>26 U/L for boys and >22 U/L for girls) without hepatitis B virus or hepatitis C virus infection [19 (link),20 (link),21 (link),22 (link)].

Well-trained staff obtained anthropometric measurements following standard procedures. Body weight was measured to the nearest 0.1 kg, and height and waist circumference (WC) were measured to the nearest 0.1 cm while the participants were wearing light clothing and no shoes. The body mass index (BMI) was calculated as the ratio of weight (kg) to height (m²) (kg/m²). Systolic and diastolic blood pressure (SBP and DBP, respectively) were obtained using a standard mercury sphygmomanometer with participants in a seated position. Blood samples were collected from an antecubital vein in the morning after an overnight fast. The serum levels of TC, high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), and fasting plasma glucose (FPG) were measured enzymatically using an Advia 1650/2400 (Siemens, New York, NY, USA) in the 2005 and 2007 surveys, and a Hitachi Automatic Analyzer 7600/7600-210 (Hitachi, Tokyo, Japan) in the 2008, 2010, 2011, 2012, 2013, 2014, and 2015 surveys.

Following an 8-hour fast, blood samples were collected from the antecubital vein, processed, and immediately refrigerated. Serum 25OHD levels were measured using radioimmunoassay (DiaSorin, Stillwater, MN). The coefficient of variation of the control material was < 7.8% and < 5.8% for low and high levels, respectively.
The serum levels of the total cholesterol (TC), HDL-C, and TG were measured using a Hitachi Automatic Analyzer 7600/7600-210 (Hitachi, Tokyo, Japan). Low-density lipoprotein cholesterol (LDL-C) was calculated using the Friedewald formula (LDL-C = TC − [HDL-C + (TG / 5)]) [24 (link)]; non-HDL-C was calculated as TC − HDL-C [25 (link)]. Dyslipidemia was defined using one of the following cutoffs specified in the American Academic of Pediatrics guidelines [11 (link)]: TC ≥ 200 mg/dL; LDL-C ≥ 130 mg/dL; TG ≥ 130 mg/dL; HDL-C < 40 mg/dL; or non-HDL-C ≥ 145 mg/dL.