BACKGROUND Sphingolipids (SPs) are ubiquitous, structurally diverse molecules that include ceramides, sphingomyelins (SMs), and sphingosines. They are involved in various pathologies, including obesity and type 2 diabetes mellitus (T2DM). Therefore, it is likely that perturbations in plasma concentrations of SPs are associated with disease. Identifying these associations may reveal useful biomarkers or provide insight into disease processes.METHODS We performed a lipidomics evaluation of molecularly distinct SPs in the plasma of 2302 ethnically Chinese Singaporeans using electrospray ionization mass spectrometry coupled with liquid chromatography. SP profiles were compared to clinical and biochemical characteristics, and subjects were evaluated with follow-up visits for 11 years.RESULTS We found that ceramides correlated positively but hexosylceramides correlated negatively with BMI and homeostatic model assessment of insulin resistance (HOMA-IR). Furthermore, SPs with a d16:1 sphingoid backbone correlated more positively with BMI and HOMA-IR, while d18:2 SPs correlated less positively, relative to canonical d18:1 SPs. We also found that higher concentrations of 2 distinct SMs were associated with a higher risk of T2DM (HR 1.45 with 95% CI 1.18–1.78 for SM d16:1/18:0 and HR 1.40 with 95% CI 1.17–1.68 for SM d18:1/18:0).CONCLUSIONS We identified significant associations between SPs and obesity/T2DM characteristics, specifically, those of hexosylceramides, d16:1 SPs, and d18:2 SPs. This suggests that the balance of SP metabolism, rather than ceramide accumulation, is associated with the pathology of obesity. We further identified 2 specific SPs that may represent prognostic biomarkers for T2DM.FUNDING National University Health System (NUHSRO/2014/085/AF-Partner/01) and the National Research Foundation Investigatorship grant (NRF-NRFI2015-05).
Wee Siong Chew, Federico Torta, Shanshan Ji, Hyungwon Choi, Husna Begum, Xueling Sim, Chin Meng Khoo, Eric Yin Hao Khoo, Wei-Yi Ong, Rob M. Van Dam, Markus R. Wenk, E. Shyong Tai, Deron R. Herr
Guidelines: The Editorial Board will only consider letters that we deem relevant and of interest to our readers. We will not post data that have not been subjected to peer review, nor will we post letters that are essentially a reiteration of another letter. All accepted letters will be posted on our website within one week of acceptance. We reserve the right to edit any letter for length, content, and clarity. Authors of all accepted letters will be asked to preview any changes. Authors will be notified by e-mail if their letters were not accepted. As this is a final decision, no appeals will be considered.
Specific requirements: All letters must be 400 words or fewer. You may enter the letter as plain text or HTML. The author's name and e-mail address are required, and will be posted with the letter. All possible conflicts of interest must be noted, even if they are not posted. If you wish to include a figure (keep in mind that non-peer-reviewed data will not be posted), please contact the editors directly at email@example.com.