BACKGROUND: Adiposity contributes to dyslipidaemia and increased risk of chronic diseases, including type 2 diabetes. Novel lipidomic profiling methods are providing new insights into the pathophysiology of chronic diseases; however limited human studies have examined the association between adiposity and lipidomic profiles. We examined whether whole plasma lipidomics were related to adiposity measured by gold-standard methods, in overweight and obese, non-diabetic adults.
METHODS: In 65 overweight or obese (BMI≥25 kg/m2), non-diabetic adults (35M/19F; age=31.3±8.5), we examined the associations between 459 lipid species across 26 lipid classes (liquid-chromatography mass-spectrometry) and adiposity (gold-standard dual X-ray absorptiometry). Additional obesity indices including BMI and waist-to-hip-ratio (WHR) were also measured. Multivariable regression was performed with adjustment for age and sex, and all analyses were adjusted for multiple testing using Benjamini-Hochberg correction.
RESULTS: Mean BMI of participants was 31.5±5.2 kg/m2 and mean % body fat was 40.1±8.7%. On univariable analyses, BMI and WHR were not associated with lipid species or classes (all p>0.05 after Benjamini-Hochberg correction). However, higher % body fat was associated with lower levels of nine lipid classes including diacylglycerols (DG) (r=-1555.1, p=0.02), triacylglycerols (TG) (r=-8747.9, p=0.03), ceramides (Cer) (r=-122.4, p=0.002), lysophosphatidylcholine (LPC) (r=-2907.1, p=0.004), alkyllysophosphatidylethanolamines (LPEp) (r=-85.5, p=0.04), phosphatidylcholines (PC) (r=-9629.1, p=0.03), alkylphosphatidylethanolamine (PEp) (r=-956.9, p=0.01), GM3 ganglioside (GM3) (r=-49.3, p=0.002), and monohexosylceramide (MHC) (r=-43.7, p=0.003). After adjustment for age and sex, % body fat remained negatively associated with the PEp and PC lipid classes (p=0.02 and p=0.049, respectively), as well as 6 individual species from the LPC lipid class (all p<0.05) and 1 from the LPE lipid class (all p=0.04).
CONCLUSION: Our novel data from a well-characterized cohort of overweight or obese but otherwise healthy non-diabetic adults suggest that increased body fat is associated with lower concentrations of several lipid species and classes. Further large-scale studies are needed to confirm this finding.