Lipidomic Signature of Changes in Adiposity: A Large Prospective Study of 5,849 Adults from the Australian Diabetes, Obesity and Lifestyle Study

Background: Lipid metabolism is tightly linked to adiposity and weight gain. Comprehensive lipidomic profiling offers new insights into the dysregulation of lipid metabolism in relation to weight gain.  Here, we investigated the relationship of the human plasma lipidome and changes in waist circumference (WC) and body mass index (BMI). Methods: Adults (2,653 men and 3,196 women), 25-95 years old who attended the baseline survey of the Australian Diabetes, Obesity and Lifestyle Study (AusDiab) and the 5-year follow-up were enrolled. A targeted lipidomic approach was used to quantify 706 distinct molecular lipid species in the plasma samples. Multiple linear regression models were used to examine the relationship between the baseline lipidomic profile and changes in WC and BMI. Metabolic scores for change in WC were generated using a ridge regression model. Findings: Alkyl-diacylglycerol such as TG(O-50:2) [NL-18:1] displayed the strongest association with change in WC (β-coefficient = 0.125 cm increment per SD increment in baseline lipid level, p = 2.78E-11). Many lipid species containing linoleate (18:2) fatty acids were negatively associated with both WC and BMI gain. Compared to traditional models, multivariate models containing lipid species identify individuals at a greater risk of gaining WC: top quintile relative to bottom quintile (odds ratio, 95% CI = 5.4, 3.8 – 6.6 for women and 2.3, 1.7 – 3.0 for men). Interpretation: Our findings define metabolic profiles that characterise individuals at risk of weight gain or WC increase and provide important insight into the biological role of lipids in obesity. Funding: National Health and Medical Research Council of Australia (Project grant APP1101320) and the Victorian Government’s Operational Infrastructure Support Program. Declaration of Interest: The authors declare no conflicts of interest Ethical Approval: The study was approved by the Human Research Ethics Committee at the Alfred Hospital, Melbourne, Australia.