Laboratory analysis Peripheral venous blood was drawn from each subject after 12 hours of fasting. Parameters of glucose homeostasis were assessed in certified University hospital laboratory: plasma glucose using hexokinase reaction (kit KONELAB, Germany), HbA1c using high-pressure liquid boronate afinit chromatography (Primus corporation), insulin using solid phase competitive chemiluminescent enzyme immunoassay (Immulite 2000). Lipid profile: total cholesterol and triglycerides were measured using enzymatic method (kit KONELAB, Germany), HDL-cholesterol using PEG modified enzymatic measurement (kit ROCHE, Switzerland). Plasma levels of free fatty acids (FFA) were measured using method already described [12]. Briefly, FFA were extracted together with neutral lipids using isooctan and cleaned by reverse extraction. FA obtained this way were derivatized to methylesters and subsequently analyzed using gas chromatography (GC). Serum AA levels were determined using capillary electrophoresis (CE) with contactless conductivity detection, which has been already described in details [3, 4]. CE measurements were carried out using HP3DCE system (Agilent Technologies, Waldbronn, Germany) equipped with a built-in contactless conductivity detector.