Several individual studies have shown that circulating levels of odd-chain SFAs and very-long-chain SFAs (VLSFAs) may have beneficial effects, but the results are mixed. While the dietary and metabolic factors that may influence VLSFAs are not well-known, a previous study observed associations of VLSFA concentrations with variants in serine palmitoyl-transferase long-chain base subunit 3 (SPTLC3) gene.
We investigated the associations of individual plasma SFAs and SPTLC3 gene rs680379 polymorphism with metabolic risk factors and type 2 diabetes (T2D).
We measured plasma SFAs using gas chromatography among 898 T2D cases and 1618 matched controls, and genotyped the SPTLC3 gene rs680379 polymorphism using the MassArray System among 1178 T2D cases and 1907 matched controls. Conditional logistic regression was used to estimate ORs and 95% CIs.
We found that plasma odd-chain SFAs and VLSFAs were correlated with favorable blood lipids and insulin resistance marker profiles. After multivariable adjustment, pentadecanoic acid (15:0) was inversely associated with the odds of T2D (OR per 1 SD difference: 0.63; 95% CI: 0.57, 0.70), as were measurements of 3 individual VLSFAs [arachidic acid (20:0), behenic acid (22:0), and lignoceric acid (24:0)], with ORs ranging from 0.60 to 0.72 (95% CIs ranging between 0.52 and 0.79). The associations between 3 individual VLSFAs and T2D were attenuated after further adjustment for triglycerides. Meanwhile, compared with the rs680379 GG genotype carriers, the ORs of T2D for the GA and AA genotype carriers were 0.81 (95% CI: 0.68-0.97) and 0.76 (95% CI: 0.61-0.96), respectively.
Plasma 15:0 and VLSFAs were inversely associated with T2D. Meanwhile, compared with the rs680379 GG genotype carriers, subjects with GA and AA genotypes were associated with decreased odds of T2D. More investigations are warranted to confirm our findings.

© The Author(s) 2021. Published by Oxford University Press on behalf of the American Society for Nutrition.