Biochemical analysis

A glucose oxidase technique using the YSI glucose analyzer (Yellow Spring Instruments Co Inc) was used to determine plasma glucose levels. Plasma levels of insulin, hsCRP, and adiponectin were measured in our Endocrine Research Laboratory using commercial kits. Plasma hsCRP levels were measured with a chemiluminescent assay (Immulite, Siemens Ltd, catalog No. LKCRP1, RRID:AB_2750938 http://antibodyregistry.org/AB_2750938). The limit of detection of the hsCRP assay was 0.1 mg/L and the within-run and between-run coefficients of variation were less than 5%. Plasma total adiponectin level (including all the multimeric forms of circulating adiponectin) was measured with enzyme-linked immunosorbent assay (ELISA, Millipore, catalog No. EZHADP-61 K, RRID:AB_2801457 https://www.antibodyregistry.org/AB_2801457); the assay sensitivity was 0.78 ng/mL and within-batch, and between-batch coefficients of variation were 1.8% and 6.2%, respectively. Hepatic alanine transaminase (ALT) and aspartate transaminase (AST) levels, complete blood count, HbA_1c, and fasting plasma lipid profiles were measured in a contract clinical laboratory.