Plasma Phospholipid Fatty Acid Profile is Altered in Both Septic and Non-Septic Critically Ill: A Correlation with Inflammatory Markers and Albumin.

This study analyzes fatty acid (FA) composition in plasma lipids and erythrocyte phospholipids while comparing septic and non-septic critically ill patients. The aim was to describe impacts of infection and the inflammatory process. Patients with severe sepsis (SP, n = 13); age-, sex- and APACHE II score-matched non-septic critically ill with systemic inflammatory response syndrome (NSP, n = 13); and age-/sex-matched healthy controls (HC, n = 13) were included in a prospective case-control study during the first 24 h after admission to the intensive care unit. In both SP and NSP, lower n-6 polyunsaturated FA (PUFA) accompanied by higher proportions of monounsaturated FA (MUFA) in plasma phospholipids (PPL) was observed relative to HC. MUFA proportion was negatively correlated with n-6 PUFA, high density lipoprotein cholesterol (HDL-C), and albumin. MUFA was positively correlated with C-reactive protein (CRP), procalcitonin (PCT), interleukins (IL-6, IL-10), oxidized low density lipoproteins (ox-LDL), and conjugated dienes (CD). In both SP and NSP, inflammatory and lipid peroxidation markers were significantly higher-CRP (p < 0.001; p = 0.08), IL-6, IL-10, TNF-α (p < 0.01, p = 0.06), ox-LDL, and CD while total cholesterol, HDL-C, LDL-C albumin, and 20:4n-6/22:6n-3 and n-6/n-3 ratios were lower compared to HC. In conclusion, the changes in plasma lipid FA profile relate to the intensity of inflammatory and peroxidative response regardless of insult etiology. The lower MUFA and higher n-6 PUFA proportions in PPL were inversely correlated with cholesterol and albumin levels.

Could human cold adaptation decrease the risk of cardiovascular disease?

The impact of repeated exposure to cold and cold adaptation on human cardiovascular health is not fully understood. The aim of the study was to determine the effect of cold adaptation on cardiovascular risk factors, thyroid hormones and the capacity of humans to reset the damaging effect of oxidative stress. Ten well cold-adapted winter swimmers (CA) and 16 non-adapted controls (CON) were enroled in this experiment to test whether cold adaptation could influence the parameters of lipoprotein metabolism, cholesterol efflux capacity (CEC), homocysteine, thyroid hormones, antioxidant defence markers (reduced glutathione (GSH), glutathione peroxidase 1 (GPX1), glutathione reductase (GR), catalase (CAT) and paraoxonase 1 (PON1)) and oxidative stress markers (concentration of conjugated dienes (CD)). A decreased apolipoprotein B/apolipoprotein A1 (ApoB/ApoA1) ratio was found in the CA group (p<0.05), but other lipoprotein parameters, including CEC, did not differ significantly. Plasma homocysteine was lower in CA subjects in comparison with controls (p<0.05). Higher triiodothyronine (T3) values were observed in the CA compared to the CON (p<0.05) group, but TSH and other thyroid hormones did not differ between both groups. CA subjects had lower activity of GPX1 (p<0.05), lower concentrations of CD (p<0.05) and increased activities of PON1 (p<0.001) compared to CON subjects. A trend for decreased activity of CAT (p=0.06) in CA compared to CON groups was also observed, but GSH levels did not differ significantly. Zn concentration was higher in the CA group than in the CON group (p<0.001). Human cold adaptation can influence oxidative stress markers. Trends towards the improvement of cardiovascular risk factors in cold-adapted subjects also indicate the positive effect of cold adaptation on cardio-protective mechanisms.