Serum saturated fatty acids containing triacylglycerols are better markers of insulin resistance than total serum triacylglycerol concentrations

Abstract

Aims/hypothesis The weak relationship between insulin resistance and total serum triacylglycerols (TGs) could be in part due to heterogeneity of TG molecules and their distribution within different lipoproteins. We determined concentrations of individual TGs and the fatty acid composition of serum and major lipoprotein particles and analysed how changes in different TGs and fatty acid composition are related to features of insulin resistance and abdominal obesity. Methods We performed lipidomic analyses of all major lipoprotein fractions using two analytical platforms in 16 individuals, who exhibited a broad range of insulin sensitivity. Results We identified 45 different TGs in serum. Serum TGs containing saturated and monounsaturated fatty acids were positively, while TGs containing essential linoleic acid (18:2 n−6) were negatively correlated with HOMA-IR. Specific serum TGs that correlated positively with HOMA-IR were also significantly positively related to HOMA-IR when measured in very-low-density lipoproteins (VLDLs), intermediate-density lipoproteins (IDLs) and LDL, but not in HDL subfraction 2 (HDL 2 ) or 3 (HDL 3 ). Analyses of proportions of esterified fatty acids within lipoproteins revealed that palmitic acid (16:0) was positively related to HOMA-IR when measured in VLDL, IDL and LDL, but not in HDL 2 or HDL 3 . Monounsaturated palmitoleic (16:1 n−7) and oleic (18:1 n−9) acids were positively related to HOMA-IR when measured in HDL 2 and HDL 3 , but not in VLDL, IDL or LDL. Linoleic acid was negatively related to HOMA-IR in all lipoproteins. Conclusions/interpretation Serum concentrations of specific TGs, such as TG(16:0/16:0/18:1) or TG(16:0/18:1/18:0), may be more precise markers of insulin resistance than total serum TG concentrations.

Circulating Triacylglycerol Signatures in Nonalcoholic Fatty Liver Disease Associated With the I148M Variant in PNPLA3 and With Obesity

“…In serum, the relative concentrations of 16:0, 16:1, and 18:0 esterified fatty acids were positively correlated with insulin resistance, and those of essential fatty acids were inversely correlated with insulin resistance (48). Similar data were observed when liver fat was plotted against the splanchnic production rate of TAGs (47).…”

Nutrition and nutrigenomics: an overview

“…However, the anthropometric data is often sufficient: height, body weight, body mass index (weight ratio in kg/height in m high per square), fat mass percentages and lean mass (measured by impedance measurement). Table 1 shows the main anthropometric and bioumoral parameters used in the general evaluation of nutrition status [40][41][42][43][44][45][46][47][48][49][50][51][52][53].…”

“…A classic nutritional deficiency index is hypoalbuminemia, particularly in elderly subjects. Other laboratory indices useful in this regard are quantization of transferrin and lymphocytes in the blood [40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57] (Table 2).…”

First-Trimester Maternal Serum Amino Acids and Acylcarnitines Are Significant Predictors of Gestational Diabetes

“…Metabolic profiles have been shown to be altered as early as 3-12 years before the diagnosis of T2DM [15][16][17]. Metabolites associated with T2DM include carbohydrates, lipids like lyso-phosphatidylcholines [17,18], fatty acids [19], acylcarnitines [20], and amino acids, particularly branched-chain amino acids (BCAAs, leucine, isoleucine, and valine) and aromatic amino acids (phenylalanine and tyrosine) [16]. Leucine, isoleucine, and valine are first converted to branched-chain keto acids (BCKAs) 4-methyl-2-oxopentanoate, 3-methyl-2-oxovalerate, and 3-methyl-2-oxobutyrate, respectively, and eventually lead to the production of C3 and C5 acylcarnitines.…”