Fig 1.
Major products of the DNL pathway.
Acetyl-Coenzyme A (acetyl CoA) is polymerized to form FAs. The initial major product of DNL is palmitic acid (16:0) which can be transformed to palmitoleic acid (16:1n-7) by Δ9 desaturation catalyzed by the Stearoyl-Coenzyme A desaturase and subsequently elongated to cis-vaccenic acid (18:1n-7) or elongated to stearic acid (18:0) and subsequently desaturated to oleic acid (18:1n-9). Myristic acid (14:0) is another possible minor product of FA synthesis. Experimental studies found that 7-hexadecanoic acid (16:1n-9) could be derived from the β-oxidation of 18:1n-9 [21]. The DNL-index is the ratio of the endogenously produced palmitic acid (16:0), the main product of DNL, and the essential FA linoleic acid (18:2n-6) whose origin is from dietary lipids. The DNL-index has been proposed as a tool to assess FA synthesis in humans [19,20].
Table 1.
Characteristics by tertiles of the DNL-index (16:0 / 18:2n-6), palmitic acid (16:0) and palmitoleic acid (16:1n-7) in men, EPIC-Potsdam study (n = 573) a.
Table 2.
Characteristics by tertiles of the DNL-index (16:0 / 18:2n-6), palmitic acid (16:0) and palmitoleic acid (16:1n-7) in women, EPIC-Potsdam study (n = 989) a.
Table 3.
Adjusted geometric means of the fatty liver index (FLI), plasma GGT and ALT and adjusted arithmetic means (95% CI) of plasma fetuin-A by tertiles of erythrocyte FA proportions for men (n = 573) and women (n = 989), EPIC-Potsdam study a.