Gluko quant glucose hexokinase

Laboratory methods concerning measurements of total 25-OHD, free 25-OHD, insulin, adiponectin and high-sensitive C-reactive protein (hs-CRP) are described in detail elsewhere (6 (link), 20 (link)). In brief, serum total 25-OHD was measured with an automated IDS-iSYS analyser (IDS Ltd., Boldon, UK) with coefficient of variation (CV) <5% and compared against in-house liquid chromatography in tandem with mass spectrometry (20 (link)), and free 25-OHD was assessed using a two-step immunoassay (Future Diagnostics BV, Wijchen, Netherlands) with CV <8.5%. Plasma glucose was analysed by spectrophotometric a hexokinase and glucose-6-phosphate dehydrogenase assay (Gluko-quant glucose/hexokinase, Roche Diagnostics) with a Hitachi Modular automatic analyser (Indianapolis, USA). Serum insulin was measured using a time-resolved immunofluorometric assay (Perkin Elmer Life Sciences) with a detection limit of 0.5 mU/L and an interassay-CV <4%. Serum adiponectin was determined using a Human Total Adiponectin/Acrp30 Quantikine ELISA Kit and serum leptin with Human Leptin R Quantikine ELISA Kit (R&D Systems) with intra- and inter-assay CV of <12%. hs-CRP was determined by an immunoturbidimetric assay on a Roche-automated clinical chemistry analysed at the central laboratory of the Helsinki University Central Hospital.