Lipidomic markers of processed meat and unprocessed red meat intake and risk of diabetes in American Indians

Objective: To identify lipidomic markers of habitual unprocessed red meat and processed meat intake and evaluate their associations with diabetes risk in American Indians.

Research Design and Methods: We studied 1,816 participants from the Strong Heart Family Study. Using untargeted liquid chromatography-mass spectrometry, we quantified 1,542 lipids (518 known) in fasting plasma at baseline and follow-up (~5 years apart). Meat intake was assessed via Food Frequency Questionnaires. Mixed-effects linear regression was used to identify lipids associated with meat consumption. Mixed-effects logistic regression was used to examine whether these lipids were associated with incident diabetes, independent of conventional risk factors, or with longitudinal glucose/insulin metrics.

Results: Of 1,076 participants with normal baseline glucose, 66 developed diabetes. After multiple testing correction, 15 known lipids, primarily plasmalogens, were associated with unprocessed red meat intake. Three plasmalogens were linked to incident diabetes (OR [95% CI]: 1.32 [1.02–1.70] to 1.39 [1.08–1.78] per SD increase in baseline levels) and higher red meat intake. Eight lipids, mainly sphingomyelins, were associated with processed meat intake. Two sphingomyelins were linked to incident diabetes (OR [95% CI]: 1.33 [1.02–1.75] and 1.36 [1.04–1.80]) and higher processed meat intake. Of 23 meat-related lipids, 20 were associated with altered glucose/insulin metrics, and 11 mediated positive associations between red or processed meat intake and fasting glucose.

Conclusion: We identified lipidomic markers of unprocessed red and processed meat consumption. Several lipids were independently associated with increased diabetes risk, potentially by mediating the association between meat intake and glucose metabolism.