Hs crp

All of the included patients underwent blood sampling at the scheduled check-up 7 to 14 days after the PSG was performed. None of the patients were on treatment for OSA during the time period between the PSG and the blood sampling. Venous blood samples were extracted after 10–12 h fasting via a polyethylene catheter inserted into the cubital vein. All of the blood sample analyses were conducted by the same biochemical laboratory and by the same biochemist according to the standard laboratory protocols. Additionally, the biochemist was highly experienced and was blinded to the participant’s role in the study.
Serum levels of UII were estimated using the enzyme immunoassay (EIA) kit for human UII (Phoenix Pharmaceuticals, Burlingame, CA, USA), according to the manufacturer’s instructions. The concentration of the analyzed quality control sample which arrived from the manufacturer was within predefined acceptable deviation. The linear range of the assay was 0.06–8.2 ng/mL and sensitivity was 0.06 ng/mL. CV within the probe was less than 10%, and between probes was less than 15%. Furthermore, the latex turbidimetric method was used for hsCRP (Abbott Laboratories, Chicago, IL, USA) level determination. All other parameters were determined according to the standard laboratory practice.

Blood samples from patients were collected from radial or femoral site of arterial catheter and processed within 1 h. Blood samples were always obtained around midday to limit circadian oscillations of neutrophil phenotypes. Haematological parameters were determined in EDTA-anticoagulated blood on a Cell-Dyn 3700 (Abbott Laboratories). Platelet poor plasma was obtained after two consecutive centrifugations at 1750 g during 15 min at room temperature. Sera were obtained following one centrifugation at 1750 g during 15 min at RT. Plasma and sera were stored at −80 °C until analysis. IL-6 and S100A9 were measured on EDTA-plasma using a Luminex assay kit (R&D Systems, Minneapolis, MN, USA) according to the manufacturer’s instructions. Nucleosome levels were quantified on EDTA-plasma with the Cell Death Detection ELISA plus kit (Sigma-Aldrich, Overijse, Belgium). Myeloperoxidase quantity and activity were analysed on EDTA-plasma by a method adapted from Franck et al. [11 (link)] using a human myeloperoxidase (MPO) Quantikine ELISA kit (R&D Systems). hs-CRP, CK-MB (Abbott Laboratories, Wavre, Belgium) and high-sensitive troponin T (hs-TnT) (Roche, Machelen, Belgium) were measured in sera by routine immunoassays.

Serum levels of total calcium, phosphate, total alkaline phosphatase, iPTH, and 25(OH)-vitamin D were measured at T0, T3, and T6. Serum levels of fibroblast growth factor-23 (FGF-23), interleukin-1β (IL-1β), and high-sensitivity C-reactive protein (hs-CRP) were measured at T0 and T6.
Serum calcium and phosphate levels were measured using a colorimetric assay. Serum iPTH levels were assessed by immunochemiluminescence (reference range: 10-65 pg/mL), while serum levels of 25(OH)-vitamin D were evaluated by radioimmunoassay (DiaSorin Liaison, Vercelli, Italy, with an average intra-assay and inter-assay coefficient of variability of 4% and 6%, respectively).
Serum concentrations of FGF-23 (Immutopics, San Clemente, USA) and IL-1β (R&D Systems, Minneapolis, USA) were measured by enzyme-linked immunosorbent assay. Serum levels of hs-CRP (Abbott, Illinois, USA) were measured by immunoturbidimetry. The measuring ranges for FGF-23, IL-1β, and hs-CRP levels were 0-2200 pg/mL, 0.48-500 pg/mL, and 0-16 mg/dL, respectively. All samples were analyzed simultaneously under standardized experimental conditions in duplicates.