Lipidomics analysis of impaired glucose tolerance and type 2 diabetes mellitus in overweight or obese elderly adults

AIMS: Aging, obesity, and type 2 diabetes mellitus (T2DM) form a metabolic disease continuum that has a continuously increasing prevalence. Lipidomics explains the complex interactions between lipid metabolism and metabolic diseases. We aimed to systematically investigate the plasma lipidome changes induced by newly diagnosed impaired glucose tolerance (IGT) and T2DM in overweight/obese elderly individuals and to identify potential biomarkers to differentiate between the IGT, T2DM, and control groups. METHODS: Plasma samples from 148 overweight/obese elderly individuals, including 52 patients with IGT, 47 patients with T2DM, and 49 euglycemic controls, were analyzed using a high-coverage nontargeted absolute quantitative lipidomics approach. RESULTS: We quantified 1840 lipids from thirty-eight classes and seven lipid categories. Among overweight/obese elderly individuals, the lipidomic profiles of IGT and T2DM patients were significantly different from those of controls, while they were similar in the IGT and T2DM groups. The concentrations of diglycerides, triglycerides, phosphatidylcholines, and ceramides were obviously altered in the IGT and T2DM groups. Particularly, IGT and T2DM induced the accumulation of triglycerides with longer carbon atom numbers (C44–50) and saturated or lower double bond numbers (n (C=C) = 0–2). Furthermore, a total of 17 potential lipidic biomarkers were identified to successfully differentiate between the IGT, T2DM, and control groups. CONCLUSIONS: In overweight/obese elderly patients, IGT and T2DM induced apparent lipidome-wide changes. This study’s results may contribute to explaining the complex dysfunctional lipid metabolism in aging, obesity, and diabetes.