Modular ppe

Body mass index (BMI) was calculated according to the formula: body weight (kg)/height²ⁱⁿ (m²). Creatinine and cholesterol levels were measured by the standard method with an automated analyzer Modular PPE (Roche Diagnostics) and Roche Diagnostics GmbH reagents (Mannheim Germany). A serum aminoterminal pro-brain natriuretic peptide (NT-proBNP) level was measured by an electrochemiluminescence immunoassay (ECLIA) method (Roche Diagnostics GmbH, Mannheim, Germany) with a immunoassay analyzer Cobas e411 (Roche Diagnostics GmbH, Mannheim, Germany). Plasma interleukin 6 (IL-6) concentration was determined by high-sensitivity ELISA using R&D Systems kits (Minneapolis, MN, USA). High-sensitivity CRP (hsCRP) levels were measured using a high-sensitivity immunoturbidimetric method (Modular PPE, Roche Diagnostics GmBH, Mannheim, Germany, sensitivity 0.11 mg/L).
Data on deaths over 9 years after beginning of the study were obtained from Universal Electronic System for Registration of the Population.

Serum and urine creatinine concentrations were assessed using Jaffe method, serum urea by kinetic UV method, and serum albumin by colorimetric method (Modular PPE, Roche Diagnostics GmbH, Mannheim, Germany).
Urinalysis was performed initially with the strip method (Combur-Test) with urinary albumin quantification using Miditron M system (Roche Diagnostics GmbH, Mannheim, Germany). In subjects in whom albuminuria was not detected with this method (< 300 mg/l), high sensitivity (< 3 mg/l) immunoturbidimetric method was used (Roche Diagnostics GmbH, Mannheim, Germany). Urine albumin-to-creatinine ratio (UACR) was calculated.
Serum C-reactive protein concentrations were assessed by an automated system (Modular PPE, Roche Diagnostics GmbH, Mannheim, Germany) with intermediate precision below 5.7%.
Serum N-terminal prohormone for brain natriuretic peptide (NT-proBNP) was assessed using the electrochemiluminescence method on Cobas E411 analyzer (Roche Diagnostics GmbH, Mannheim, Germany) with intermediate precision below 4.6%.

Venous blood was collected using a vacuum system and delivered in a cooler to local laboratories within 2 h, where serum and plasma samples were separated and frozen. All samples were then delivered to the Department of Human Epigenetics, Mossakowski Medical Research Centre in Warsaw. All of the IL-6 and CRP measurements were performed in the same laboratory. Interleukin-6 levels were measured in serum using ELISA (R&D System, Minneapolis, MN, USA, sensitivity 0.04 pg/mL) in 3895 individuals and CRP (high sensitivity CRP) levels were measured using a high-sensitivity immunoturbidymetric method (Modular PPE, Roche Diagnostics GmBH, Mannheim, Germany, sensitivity 0.11 mg/L) in 4093 individuals. In the other PolSenior participants, these measurements were not performed mostly because of refusal to provide blood or because an insufficient amount of serum was collected. Other biochemical parameters were assessed using routine techniques [30 (link)]. Study subjects with leukocyte counts >10,000/μL (indicating a considerable risk of ongoing infection) and/or who were being treated with glucocorticoids were excluded from further analyses. Therefore, analyses of IL-6 were performed in 3496 subjects, and of CRP were performed in 3632 subjects. In some of the study subjects, only IL-6 or only CRP was measured. The results were presented as median [1^st quartile, 3^rd quartile] values.