Table 5.

Diagnostic accuracy of plasma oxylipin or free fatty acid levels for grading hepatic steatosis.

	Steatosis Grade	AUCROC	p	95% Interval Confidence	Threshold (nM)	TPF (%)	FPF (%)
12HEST (nM)	IFC0 vs. ≥IFC1	0.572	0.338	0.425–0.718
	≤IFC1 vs. ≥IFC2	0.661	0.014	0.535–0.788	12.3	83	72
	≤IFC2 vs. IFC3	0.694	0.047	0.477–0.910	30	80	53
	IFC0 vs. IFC3	0.690	0.110	0.439–0.942
PGF2α (nM)	IFC0 vs. ≥IFC1	0.572	0.338	0.422–0.722
	≤IFC1 vs. ≥IFC2	0.581	0.215	0.441–0.721
	≤IFC2 vs. IFC3	0.748	0.011	0.537–0.958	0.675	80	14
	IFC0 vs. IFC3	0.731	0.050	0.494–0.968	0.665	78	16
15HETE (nM)	IFC0 vs. ≥IFC1	0.579	0.292	0.430–0.728
	≤IFC1 vs. ≥IFC2	0.552	0.430	0.415–0.688
	≤IFC2 vs. IFC3	0.689	0.050	0.484–0.895	0.675	80	14
	IFC0 vs. IFC3	0.696	0.099	0.464–0.927
ETA (nM)	IFC0 vs. ≥IFC1	0.647	0.050	0.525–0.768	0.42	82	79
	≤IFC1 vs. ≥IFC2	0.573	0.267	0.434–0.711
	≤IFC2 vs. IFC3	0.626	0.197	0.397–0.854
	IFC0 vs. IFC3	0.661	0.176	0.390–0.932

The discriminatory capability of plasma oxylipin or fatty acid concentrations for different steatosis grades was tested by using the following dichotomizations: IFC0 vs. IFC1 or greater (IFC0 vs. ≥IFC1); IFC1 or less vs. IFC2 or greater (≤IFC1 vs. ≥IFC2); IFC2 or less vs. IFC3 (≤IFC2 vs. IFC3); IFC0 vs. IFC3 (IFC0 vs. IFC3). For each set of dichotomized steatosis grades, the area under the receiver operating characteristic curve (AUCROC) was calculated. The oxylipins or fatty acids with an AUCROC significantly different from 0.5 were selected as parameters with discriminant capability. The lowest plasma oxylipin or fatty acid threshold value that provided 80% or greater specificity to distinguish between dichotomized steatosis grades was selected. At that oxylipin or fatty acid threshold value, the positive predictive value and negative predictive value to distinguish between dichotomized steatosis grades were calculated. AUCROC: area under the curve receiver operating characteristic; FPF: false positive fraction; IFC: intrahepatic fat content; TPF: true positive fraction; p: significance vs. 0.5 as non-discriminating AUCROC value. ETA: 8,11,14,17-eicosatetraenoic acid; 15HETE: 15-Hydroxy-5,8,11,13-Eicosatetraenoic; 12HEST: 12-Hydroxyoctadecanoic acid. PGF2α: (Z)-7-[(1R,2R,3R,5S)-3,5-dihydroxy-2-[(E,3S)-3-hydroxyoct-1-enyl]cyclopentyl]hept-5-enoic acid (Prostaglandin 2α). IFC0 (stage 0 or control group without steatosis) IFC < 6.4%; IFC1 (stage 1 with mild steatosis) 6.4% ≤ IFC < 17.4%; IFC2 (stage 2 with moderate steatosis) 17.4% ≤ IFC < 22.1%; and IFC3 (stage 3 with severe steatosis) IFC ≥ 22.1%.