Baseline characteristics of study population.

<p>Baseline characteristics of study population.</p

Baseline and end of treatment levels of TNF- α in vitamin E responders and non-responders are shown.

<p>The baseline values in both groups are comparable. At the end of treatment, the levels significantly decreased in vitamin E responders (p = 0.002).</p

Baseline and end of treatment levels of gamma glutamyl transpeptidase in vitamin E responders and non-responders are shown.

<p>The baseline values in both groups are comparable. At the end of treatment, the levels decreased in both groups but the degree of decrease was greater in vitamin E responders. This however was only a trend and not statistically significant.</p

The circulating levels of α-tocopherol, γ-tocopherol and γ-carboxyethylhydroxychroman (CEHC) a metabolite of vitamin E are shown at baseline (panel A) and at end of treatment (panel B) for subjects receiving vitamin E who either met histologic criteria for a response (responders) or met the criteria for non-response.

<p>CEHC was significantly lower at baseline in vitamin E treatment responders. The levels of α-, and γ-tocopherols were similar in the two groups at baseline. There was a similar enrichment of α-tocopherol in both responders and non-responders. Conversely, there was a relative de-enrichment of γ-tocopherol in both groups. These data indicate that the histologic response to vitamin E was not a simple response of the amount of vitamin E enrichment of plasma.</p

End of treatment vitamin E and placebo response biomarkers.

<p>ANCOVA models adjusting for baseline metabolites level with Tukey Method for multiple comparison.</p

Genetic Polymorphism of Cytochrome P450 4F2, Vitamin E Level and Histological Response in Adults and Children with Nonalcoholic Fatty Liver Disease Who Participated in PIVENS and TONIC Clinical Trials

<div><p>Vitamin E improved liver histology in children and adults with NAFLD who participated in TONIC and PIVENS clinical trials, but with significant inter-individual variability in its efficacy. Cytochrome P450 4F2 (CYP4F2) is the major enzyme metabolizing Vit E, with two common genetic variants (V433M, rs2108622 and W12G, rs3093105) found to alter its activity. We investigated the relationship between CYP4F2 genotypes, α-tocopherol levels and histological improvement in these two trials. V433M and W12G variants were genotyped in TONIC (n = 155) and PIVENS (n = 213) DNA samples. The relationships between CYP4F2 genotypes, plasma α-tocopherol levels at baseline and weeks 48 (w48) and 96 (w96) and histological end points (overall improvement in liver histology and resolution of NASH) were investigated. As a result, the V433M genotype was significantly associated with baseline plasma α-tocopherol in the TONIC trial (p = 0.004), but not in PIVENS. Among those receiving Vit E treatment, CYP4F2 V433M genotype was associated with significantly decreased plasma α-tocopherol levels at w48 (p = 0.003 for PIVENS and p = 0.026 for TONIC) but not at w96. The w96 α-tocopherol level was significantly associated with resolution of NASH (p = 0.006) and overall histology improvement (p = 0.021)in the PIVENS, but not in the TONIC trial. There was no significant association between CYP4F2 genotypes and histological end points in either trial. Our study suggested the a moderate role of CYP4F2 polymorphisms in affecting the pharmacokinetics of Vit E as a therapeutic agent. In addition, there may be age-dependent relationship between CYP4F2 genetic variability and Vit E pharmacokinetics in NAFLD.</p></div

Association between α-tocopherol level during treatment and histological endpoints among Vit E treated participants in PIVENS and TONIC.

<p>*See text for definitions.</p

Association between CYP4F2 V433M polymorphism and α-tocopherol levels at baseline (entire cohort) and during the intervention phase (in Vit E treated participants) in PIVENS and TONIC trials.

<p>Data shown in Box (horizontal bar in the box indicates median) and whiskers plot (with 10–90 percentile). Panel A: Relationship between V433M genotype and baseline α tocopherol level in PIVENS (p = ns). Panel B: Relationship between V433M genotype and baseline α tocopherol level in TONIC (p = 0.004). Panel C: Relationship between V433M genotype and week 48 α tocopherol level in PIVENS (p = 0.004). Panel D: Relationship between V433M genotype and week 48 α tocopherol level in TONIC (p = 0.0002).</p

Association between CYP4F2 polymorphisms and histological response.

<p>Association between CYP4F2 polymorphisms and histological response.</p

Plasma α-tocopherol levels at baseline and during PIVENS and TONIC clinical trials.

<p>Data are shown as median and range (min-max) of plasma α-tocopherol adjusted for total cholesterol (mg/g).</p><p>*Baseline plasma α-tocopherol in PIVENS was significantly higher than the TONIC cohort (p = 4.8×10⁻⁵).</p><p>α-toco =  α-tocopherol; Piog = Pioglitazone; Met = Metformin; PLB = placebo.</p