Browsing by Author "Sookoian, Silvia"

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    ADH1B*2 is Associated With Reduced Severity of Nonalcoholic Fatty Liver Disease in Adults, Independent of Alcohol Consumption
    (Elsevier, 2020) Vilar-Gomez, Eduardo; Sookoian, Silvia; Pirola, Carlos Jose; Liang, Tiebing; Gawrieh, Samer; Cummings, Oscar; Liu, Wanqing; Chalasani, Naga; Medicine, School of Medicine
    Background & Aims Alcohol dehydrogenase 1B (ADH1B) is involved in alcohol metabolism. The allele A ( ADH1B*2) of rs1229984: A>G variant in ADH1B is associated a higher alcohol metabolizing activity, compared to the ancestral allele G ( ADH1B*1). Moderate alcohol consumption is associated with reduced severity of nonalcoholic fatty liver disease (NAFLD), based on histologic analysis, compared with no alcohol consumption. However, it is unclear whether ADH1B*2 modifies the relationship between moderate alcohol consumption and severity of NAFLD. We examined the association between ADH1B*2 and moderate alcohol consumption and histologic severity of NAFLD. Methods We collected data from 1557 multi-ethnic adult patients with biopsy-proven NAFLD enrolled into 4 different studies conducted by the NASH Clinical Research Network. Histories of alcohol consumption were obtained from answers to standardized questionnaires. Liver biopsies were analyzed by histology and scored centrally according to the NASH CRN criteria. We performed covariate adjusted logistic regressions to identify associations between histologic features of NAFLD severity and moderate alcohol consumption and/or ADH1B*2. Results A higher proportion of Asians/Pacific Islanders/Hawaiians carried the ADH1B*2 allele (86%) than other racial groups (4%–13%). However, the study population comprised mostly non-Hispanic whites (1153 patients, 74%), so the primary analysis focused on this group. Among them, 433 were moderate drinkers and 90 were ADH1B*2 carriers. After we adjusted for confounders, including alcohol consumption status, ADH1B*2 was associated with lower frequency of steatohepatitis (odds ratio [OR], 0.52; P<.01) or fibrosis (odds ratio, 0.69; P=.050) compared with ADH1B*1. Moderate alcohol consumption (g/day) reduced the severity of NAFLD in patients with ADH1B*1 or ADH1B*2. However, ADH1B*2, compared to ADH1B*1, was associated with a reduced risk of definite NASH ( ADH1B*2 OR, 0.80; P<.01 vs ADH1B*1 OR, 0.96; P=.036) and a reduced risk of an NAFLD activity score of 4 or higher ( ADH1B*2 OR, 0.83; P=.012 vs ADH1B*1 OR, 0.96; P=.048) ( P<.01 for the difference in the effect of moderate alcohol consumption between alleles). The relationship between body mass index and NAFLD severity was significantly modified by ADH1B*2, even after we controlled for alcohol consumption. Conclusions ADH1B*2 reduces the risk of NASH and fibrosis in adults with NAFLD regardless of alcohol consumption status. ADH1B*2 might modify the association between high body mass index and NAFLD severity.
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    Impact of the Association Between PNPLA3 Genetic Variation and Dietary Intake on the Risk of Significant Fibrosis in Patients With NAFLD
    (Wolters Kluwer, 2021) Vilar-Gomez, Eduardo; Pirola, Carlos Jose; Sookoian, Silvia; Wilson, Laura A.; Belt, Patricia; Liang, Tiebing; Liu, Wanqing; Chalasani, Naga; Medicine, School of Medicine
    Introduction: This study explored the relationship between patatin-like phospholipase domain-containing 3 gene (PNPLA3 rs738409), nutrient intake, and liver histology severity in patients with nonalcoholic fatty liver disease (NAFLD). Methods: PNPLA3-rs738409 variant was genotyped in 452 non-Hispanic whites with histologically confirmed NAFLD who completed Food Frequency Questionnaire within 6 months of their liver biopsy. The fibrosis severity on liver histology was the outcome of interest. Results: The distribution of PNPLA3 genotypes was CC: 28%, CG: 46%, and GG: 25%. High-carbohydrate (% of energy/d) intake was positively associated (adjusted [Adj] odds ratio [OR]: 1.03, P < 0.01), whereas higher n-3 polyunsaturated fatty acids (n-3 PUFAs) (g/d) (Adj. OR: 0.17, P < 0.01), isoflavones (mg/d) (Adj. OR: 0.74, P = 0.049), methionine (mg/d) (Adj. OR: 0.32, P < 0.01), and choline (mg/d) (Adj. OR: 0.32, P < 0.01) intakes were inversely associated with increased risk of significant fibrosis (stage of fibrosis ≥2). By using an additive model of inheritance, our moderation analysis showed that PNPLA3 rs738409 significantly modulates the relationship between carbohydrate (%), n-3 PUFAs, total isoflavones, methionine, and choline intakes and fibrosis severity in a dose-dependent, genotype manner. These dietary factors tended to have a larger and significant effect on fibrosis severity among rs738409 G-allele carriers. Associations between significant fibrosis and carbohydrates (Adj. OR: 1.04, P = 0.019), n-3 PUFAs (Adj. OR: 0.16, P < 0.01), isoflavones (Adj. OR: 0.65, P = 0.025), methionine (Adj. OR: 0.30, P < 0.01), and total choline (Adj. OR: 0.29, P < 0.01) intakes remained significant only among rs738409 G-allele carriers. Discussion: This gene-diet interaction study suggests that PNPLA3 rs738409 G-allele might modulate the effect of specific dietary nutrients on risk of fibrosis in patients with NAFLD.
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    PNPLA3 rs738409 and Risk of Fibrosis in NAFLD: Exploring Mediation Pathways Through Intermediate Histological Features
    (Wiley, 2022) Vilar-Gomez, Eduardo; Pirola, Carlos J.; Sookoian, Silvia; Wilson, Laura A.; Liang, Tiebing; Chalasani, Naga; Medicine, School of Medicine
    Background & Aims It is unclear whether rs738409 (p.I148M) missense variant in patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 promotes fibrosis development by triggering specific fibrogenic pathways or by creating an unfavorable microenvironment by promoting steatosis, inflammation, and ultimately fibrosis. We tested the hypothesis that intermediate histologic traits, including steatosis, lobular and portal inflammation, and ballooning may determine the effect of rs738409 on liver fibrosis among individuals with biopsy-proven NAFLD. Approach and Results Causal mediation models including multiple mediators in parallel or sequentially were performed to examine the effect of rs738409, by decomposing its total effect on fibrosis severity into direct and indirect effects, mediated by histology traits in 1153 Non-Hispanic White (NHW) patients. Total effect of rs738409 on fibrosis was β=0.19 (95% CI: 0.09-0.29). The direct effect of rs738409 on fibrosis upon removing mediators' effects was β=0.09 (95% CI: 0.01-0.17) and the indirect effect of rs738409 on fibrosis through all mediators' effects were β=0.010 (95% CI: 0.04-0.15). Among all mediators, the greatest estimated effect size was displayed by portal inflammation (β=0.09, 95% CI: 0.05-0.12). Among different sequential combinations of histology traits, the path including lobular inflammation followed by ballooning degeneration displayed the most significant indirect effect (β=0.023, 95% CI: 0.011-0.037). Mediation analysis in a separate group of 404 individuals with biopsy-proven NAFLD from other races and ethnicity showed similar results. Conclusions In NAFLD, nearly half of the total effect of the rs738409 G allele on fibrosis severity could be explained by a direct pathway, suggesting that rs738409 may promote fibrosis development by activating specific fibrogenic pathways. A large proportion of the indirect effect of rs738409 on fibrosis severity is mediated through portal inflammation.
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    PNPLA3 rs738409 and Risk of Fibrosis in NAFLD: Exploring Mediation Pathways Through Intermediate Histological Features
    (Wolters Kluwer, 2022) Vilar-Gomez, Eduardo; Pirola, Carlos J.; Sookoian, Silvia; Wilson, Laura A.; Lian, Tiebing; Chalasani, Naga; Medicine, School of Medicine
    Background and aims: It is unclear whether rs738409 (p.I148M) missense variant in patatin-like phospholipase domain-containing 3 rs738409 promotes fibrosis development by triggering specific fibrogenic pathways or by creating an unfavorable microenvironment by promoting steatosis, inflammation, and ultimately fibrosis. We tested the hypothesis that intermediate histologic traits, including steatosis, lobular and portal inflammation, and ballooning may determine the effect of rs738409 on liver fibrosis among individuals with biopsy-proven NAFLD. Approach and results: Causal mediation models including multiple mediators in parallel or sequentially were performed to examine the effect of rs738409, by decomposing its total effect on fibrosis severity into direct and indirect effects, mediated by histology traits in 1153 non-Hispanic White patients. Total effect of rs738409 on fibrosis was β = 0.19 (95% CI: 0.09-0.29). The direct effect of rs738409 on fibrosis after removing mediators' effects was β = 0.09 (95% CI: 0.01-0.17) and the indirect effect of rs738409 on fibrosis through all mediators' effects were β = 0.010 (95% CI: 0.04-0.15). Among all mediators, the greatest estimated effect size was displayed by portal inflammation (β = 0.09, 95% CI: 0.05-0.12). Among different sequential combinations of histology traits, the path including lobular inflammation followed by ballooning degeneration displayed the most significant indirect effect (β = 0.023, 95% CI: 0.011-0.037). Mediation analysis in a separate group of 404 individuals with biopsy-proven NAFLD from other races and ethnicity showed similar results. Conclusions: In NAFLD, nearly half of the total effect of the rs738409 G allele on fibrosis severity could be explained by a direct pathway, suggesting that rs738409 may promote fibrosis development by activating specific fibrogenic pathways. A large proportion of the indirect effect of rs738409 on fibrosis severity is mediated through portal inflammation.
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    The Protection Conferred by HSD17B13 rs72613567 Polymorphism on Risk of Steatohepatitis and Fibrosis May Be Limited to Selected Subgroups of Patients With NAFLD
    (Wolters Kluwer, 2021-09-10) Vilar-Gomez, Eduardo; Pirola, Carlos J.; Sookoian, Silvia; Wilson, Laura A.; Liang, Tiebing; Chalasani, Naga; Medicine, School of Medicine
    Introduction: Our study aimed to explore how PNPLA3 rs738409 or phenotypic risk factors may moderate the relationship between HSD17B13 rs72613567 and risk of steatohepatitis and fibrosis. Methods: This analysis consisted of 1,153 non-Hispanic whites with biopsy-proven nonalcoholic fatty liver disease enrolled in the nonalcoholic steatohepatitis Clinical Research Network studies. Nonalcoholic fatty liver disease severity was determined by liver histology scored centrally according to the nonalcoholic steatohepatitis Clinical Research Network criteria. Moderation and logistic regression analyses were performed to identify the influence of moderators (PNPLA3 rs738409, age, sex, body mass index, and diabetes) on the relationship between HSD17B13 rs72613567 and risk of steatohepatitis and fibrosis. Results: HSD17B13 rs72613567 genotype frequency was as follows: (-/-), 64%; (-/A), 30%; (A/A), 6%. Moderation analysis showed that the protective effect of HSD17B13 rs72613567 A-allele on risk of steatohepatitis remained only significant among patients with PNPLA3 rs738409 genotype CC (β coeff: -0.19, P = 0.019), women (β coeff: -0.18, P < 0.001), patients of age ≥ 45 years (β coeff: -0.18, P < 0.001), patients with body mass index ≥ 35 kg/m2 (β coeff: -0.17, P < 0.001), and patients with diabetes (β coeff: -0.18, P = 0.020). Among women, the protective effect of HSD17B131 rs72613567 A-allele on risk of steatohepatitis was stronger in those aged ≥ 51 years. Logistic regression-based sensitivity analysis including various important subgroups confirmed our observations. Discussion: The protection conferred by HSD17B13 rs72613567 A-allele on risk of steatohepatitis and fibrosis may be limited to selected subgroups of individuals who are aged ≥ 45 years, women and have class ≥ 2 obesity or diabetes, and those with PNPLA3 rs738409 CC genotype.