N-6 from different sources protect from metabolic alterations to obese patients: a factor analysis

First, to analyze the interactions among fatty acids (FAs) from diet, plasma and subcutaneous and visceral adipose tissue (AT), and second, the relationship among FAs from these different sources and obesity-related alterations in extreme obesity. We studied 20 extreme obese subjects. A food-frequency questionnaire was used to determine the FA intakes. Serum and AT (subcutaneous and visceral) FA concentrations were determined by gas chromatography. Cardiometabolic risk parameters were assessed. Principal factor analysis was performed to define specific FA factors in the metabolic alterations. We found important associations among diet, plasma, and AT FA and cardiometabolic parameters. In this regard, it is interesting to highlight the negative associations between plasma cholesterol and dietary n-3 FA. In the subcutaneous depot, as occurred in plasma, n-6 and polyunsaturated FAs (PUFA) were negatively associated with triacylglycerols (TGs). Factor analysis revealed TGs as the unique cardiovascular risk parameter appearing in the first factor (F1), together with n-6 (load factor = 0.94) and PUFA (0.91). Besides, n-3 from diet and plasma appeared in the third factor inversely related to cholesterol, low-density lipoprotein cholesterol (LDL-c), and insulin. In an opposite way, dietary and AT trans FAs and saturated FA (SFA) were associated to an increase of the metabolic risk. We have shown, for the first time, the importance of n-6 and PUFAs composition as protective factors against metabolic alterations in extreme obese subjects. These findings support current dietary recommendations to increase PUFA intakes and restrict saturated and trans FA intakes even in extreme obesity.