Adults with obesity and hyperglycemia have higher arachidonic and docosahexaenoic acid in subcutaneous adipose tissue

In obesity, fatty acid (FA) accumulation may impair AT function, promoting insulin resistance and development of type 2 diabetes mellitus (T2DM). However, the contribution of visceral AT (VAT) and subcutaneous AT (SAT) specific FAs to metabolic dysregulation in obesity and T2DM remains unclear, highlighting the importance of examining the FA composition between AT depots. This study examined differences in FA profile and lipid fractions across AT depots in individuals with obesity and hyperglycemia. The primary focus was on polyunsaturated fatty acids (PUFAs) given their relevance to cardiometabolic health. Thirty participants matching VAT and SAT samples from bariatric surgery donors (BMI ≥ 30 kg/m²) were examined and were further stratified into groups of fasted normoglycemia or hyperglycemia. For the total FA profile, the concentrations (μmol/g) of arachidonic acid (ARA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) were higher in the SAT compared to VAT depot; ARA and DHA concentrations were higher in the hyperglycemia compared to normoglycemia group. Further analysis in six different lipid fractions including triacylglycerol, diacylglycerol, monoacylglycerol, free fatty acids, phospholipid and cholesteryl esters exhibited similarly higher ARA, EPA, and DHA in the SAT compared to VAT depot. However, differences between normoglycemia and hyperglycemia groups were fraction- and FA-specific, rather than uniform across all lipid classes. These results demonstrate that VAT and SAT depots differentially store FAs as a function of glycemic status in obesity, highlighting distinct differences in PUFA metabolism and availability that may have important implications for AT function and metabolic health.