2.1. Measurements
Albuminuria, proteinuria
BLOOD, KIDNEY, RECRUITMENT, POLAND
Information on demographics, socioeconomics, parent’s pre-pregnancy weight and height, the course of pregnancy, medical history, and child anthropometric data at birth was obtained from standardized parent interviews at recruitment. Self-reported data about maternal alcohol consumption and smoking during and before pregnancy were gathered in the baseline questionnaire. Weight was measured in underwear on a SECA 702/703 digital scale (10 g precision) and length/height were measured in a SECA 232/242 stadiometer. BMI (kg/mBlood pressure (mmHg) was measured with a Dinamap ProCare 100/200 digital blood pressure monitor. Blood pressure was determined in duplicate at least 15 min from arrival at the center and after at least 5 min of rest on the left arm supported by a slightly elevated horizontal support. Measurements were separated by at least 5 min. Kidney size was assessed by ultrasonography. Trained and blinded examiners using a linear or sector ultrasound (5–7.5 MHz) with a posterior approach in the prone position or a lateral approach in the prone position measured the longest length possible. Length, width, maximum depth in the longitudinal section (D1), and maximum depth in the transverse section (perpendicular to the hilar region) (D2) of both kidneys were measured (cm). Kidney volume was determined by the equation of an ellipsoid (kidney volume (cmUrinary osmolarity (mmol/L) was measured using an osmometer. Urinary creatinine (mg/dL) was analyzed using the kinetic Jaffe’s reaction in an automated ADVIA 1650/Mega Bayer R (Leverkusen, Germany). Albuminuria and proteinuria were determined on Alinity c Analyser (Abbott Laboratories, Chicago, IL, USA) by turbidimetric immunoassay and expressed as the urinary albumin/creatinine ratio (mg/g) and urinary protein/creatinine ratio (mg/mg). Samples were analyzed in a central laboratory (Diagnostic Laboratory, The Children’s Memorial Health Institute, Warsaw, Poland).