Blood lipids Sample Clauses

Blood lipids. Analyses of TC, HDL-C and TAG were carried out by Xx Xxx Xxxxxxxx at the Department of Clinical Biochemistry, King’s College Hospital. TC was determined using an enzymatic method using cholesterol esterase, cholesterol oxidase and peroxidase in a chemiluminescent reaction to produce a red quinoneimine dye. The increase in absorbance was measured as an endpoint reaction at 505/694 nm. For RISCK samples, inter-assay CVs were 1.1, 1.5 and 1.0 at 3.9, 5.2 and 5.7 mmol/L respectively. For MARINA samples inter-assay CVs were 1.1, 1.5 and 1.0 % at 3.9, 5.1 and 5.7 mmol/L respectively. HDL-C was analysed using a two-step automated procedure (Bayer Advia Direct HDL-C method). For RISCK samples CVs were 2.2, 2.1 and 2.5 at 0.91, 1.39 and 1.95 mmol/L respectively and for MARINA samples CVs were 2.2, 2.1 and 2.5 % at concentrations of 0.91, 1.39 and 1.95 mmol/L respectively. TAG was measured using an enzymatic assay (The Bayer Advia method). For RISCK samples, CVs were 2.5 and 1.5 at 1.32 and 2.36 mmol/L respectively and for MARINA samples CVs were 2.5 and 1.5 % at concentrations of 1.32 and 2.36 mmol/L respectively. LDL-C was calculated using the Friedwald formula if fasting plasma TG concentrations were < 4.49 mmol/L. The formula used was: LDL-C = TC - HDL-C - (TAG / 2.2) (Xxxxxxxxxx et al, 1972). For RISCK samples, plasma Apo B and Apo A1 were measured at the University of Surrey using commercially available kits (Randox, UK) that employ immuno- turbidimetric assays. The proportion of small dense LDL was measured by ultracentrifugation of the LDL fraction on an iodixanol gradient at the University of Surrey. Fasted plasma phospholipid fatty acids were measured by GC at the University of Reading as described by (Xxxxx et al, 2009). For MARINA samples, erythrocyte membrane phospholipid fatty acid composition measured using capillary gas liquid chromatography as described by Xxxxxxx et al. (2006). Mean inter-assay and intra-assay CVs were 3% and 2% respectively.