Objective: While small amounts of odd-chain fatty acids (OCFAs) and branched-chain fatty acids (BCFAs) were known to be present in mammals, it was quite recently that they were shown to play an important role in human health. However, still little is known on OCFA and BCFA profiles in subjects who have obesity. The aim of this study was to verify whether obesity is associated with changes in serum OCFA and BCFA profiles. Methods: Serum content of fatty acids was determined by gas chromatography-mass spectroscopy in 23 patients with excess weight and 21 nonobese controls. Results: Six OCFAs and six BCFAs (three iso-BCFAs and three anteiso-BCFAs) were found in sera from the examined subjects. Patients with excess weight presented with significantly lower serum iso-BCFA levels than the controls. Total serum content of iso-BCFAs correlated inversely with serum insulin, triglycerides, and 18:1/18:0 desaturation index. Both OCFA and iso-BCFA levels correlated inversely with Creactive protein concentration. Conclusions: Lower iso-BCFA content in patients with excess weight may be involved in elevation of serum concentration of triglycerides and inflammation. Decreased contents of iso-BCFAs in subjects with have obesity, and established anti-inflammatory, antidiabetic, and anticancer properties of these fatty acids, point to potential beneficial effects of an iso-BCFA-rich diet.

We recently reported the presence of various cyclopropane fatty acids—among them, cyclopropaneoctanoic acid 2-hexyl—in the adipose tissue of obese women. The aim of this study was to verify whether the presence of cyclopropaneoctanoic acid 2-hexyl in human serum was associated with obesity or chronic kidney disease (both being related to dyslipidemia), and to find potential associations between the serum level of this compound and specific markers of the these conditions. The serum concentration of cyclopropaneoctanoic acid 2-hexyl was determined by gas chromatography–mass spectrometry (GC–MS) in non-obese controls, obese patients, obese patients after a 3-month low-calorie diet, and individuals with chronic kidney disease. Obese patients and those with chronic kidney disease presented with higher serum levels of cyclopropaneoctanoic acid 2-hexyl than controls. Switching obese individuals to a low-calorie (low-lipid) diet resulted in a reduction in this fatty acid concentration to the level observed in controls. Cyclopropaneoctanoic acid 2-hexyl was also found in foods derived from animal fat. Serum concentrations of triacylglycerols in the analyzed groups followed a pattern similar to that for serum cyclopropaneoctanoic acid 2-hexyl, and these variables were positively correlated with each other among the studied groups. Patients with hypertriglyceridemia-related conditions presented with elevated serum levels of cyclopropaneoctanoic acid 2-hexyl. Our findings suggest that its high serum level is related to high serum triacylglycerol concentrations rather than to body mass or BMI.

Chronic kidney disease (CKD) is associated with an increased level of leptin and an abnormal fatty acid (FA) profile in the serum. However, there are no data on the associations between them, and the reason for increased serum levels in patients with CKD is not well elucidated. Recently, we found that a CKD-related abnormal FA profile caused significant changes in the expression of genes involved in lipid metabolism in hepatocytes. The aim of this study was to examine whether leptin gene expression in subcutaneous adipose tissue (SAT) of patients with CKD may contribute to increased serum levels of this adipokine and whether the abnormal serum FA profile observed in CKD patients has an impact on leptin gene expression in adipocytes. The FA profile was measured in serum samples from patients with CKD and controls by GC-MS. The relative mRNA levels of leptin were measured in SAT by Real-Time PCR. Moreover, the effect of the CKD-related abnormal FA profile on leptin gene expression was studied in in vitro cultured 3T3-L1 adipocytes. Patients with CKD had higher concentrations of serum leptin than controls and higher expression level of the leptin gene in SAT. They also had increased serum monounsaturated FAs and decreased polyunsaturated FAs. The incubation of adipocytes with FAs isolated from CKD patients resulted in an increase of the levels of leptin mRNA. Increased leptin gene expression in SAT may contribute to elevated concentrations of these adipokine in patients with CKD. CKD-related alterations of the FA profile may contribute to elevated serum leptin concentrations in patients with CKD by increasing the gene expression of this adipokine in SAT.

Our results indicate that improvement of insulin resistance, lipidemia, and blood pressure as well as reduction of systemic inflammation after bariatric surgery were associated with the increase of serum NO concentration. We propose that the increase in serum NO concentration contribute to diverse beneficial effects of weight loss after bariatric surgery especially in the context of risk of atherosclerosis.

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