Do alcohol-metabolizing enzyme gene polymorphisms increase... : Hepatology (original) (raw)

Liver Failure and Liver Disease

Do alcohol-metabolizing enzyme gene polymorphisms increase the risk of alcoholism and alcoholic liver disease?

Zintzaras, Elias1,*; Stefanidis, Ioannis2; Santos, Mauro3; Vidal, Francesc4

1_Department of Biomathematics, University of Thessaly School of Medicine, Larissa, Greece_

2_Department of Internal Medicine, University of Thessaly School of Medicine, Larissa, Greece_

3_Department de Genètica i de Microbiologia, Grup de Biologia Evolutiva (GBE), Universitat Autònoma de Barcelona, Barcelona, Spain_

4_Department of Internal Medicine, Hospital Universitari de Tarragona Joan XXIII, Universitat Rovira i Virgili, Tarragona, Spain_

*Department of Biomathematics, University of Thessaly School of Medicine, Papakyriazy 22, Larissa 41222, Greece

Email:[email protected]

Received 1 June 2005; Accepted 15 November 2005

Published online in Wiley InterScience (www.interscience.wiley.com).

Grant sponsor: Red de Centros de Metabolismo y Nutrición C03/08; Grant sponsor: Fundación Ramón Areces.

Potential conflict of interest: Nothing to report.

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Abstract

Case–control studies that have investigated the association between alcoholism and alcohol-induced liver damage and the ADH2 , ADH3 , CYP2E1 , and ADLH2 polymorphisms have reported controversial or inconclusive results. Thus, we conducted a meta-analysis of 50 association studies of the above polymorphisms. We explored potential sources of heterogeneity and bias, performed subgroup analyses by racial background and sex, performed sensitivity analyses for studies not in Hardy-Weinberg equilibrium, and performed a subgroup analysis for cases that met strict criteria for alcoholism. The present meta-analysis underscores significant associations of ADH2 * 1 , ADH3 * 2 , and ALDH2 * 1 alleles and the risk of alcoholism (OR = 1.89 [95% CI 1.56–2.28], 1.32 [95% CI 1.12–1.57], and 4.35 [95% CI 3.04–6.23], respectively). The subsequent subgroup analyses showed association for ADH2*1 and ADH3*2 only in East Asians (OR = 2.23 [95% CI 1.81–2.74] and 1.91 [95% CI 1.45–2.53], respectively) and East Asian males (OR = 2.21 [95% CI 1.57–3.10], 1.69 [95% CI 1.10–2.59], respectively). In East Asian males, the OR for ALDH2*1 was 3.66 (95% CI 1.68–7.96). In Caucasians, sensitivity analysis revealed an association for ADH2*1 in alcoholism (OR = 1.62 [95% CI 1.22–1.89]). When strict criteria were imposed, the pattern of results remained unaltered. For liver disease, there were no significant associations for ADH2*1, ADH3*2, or ALDH2*1 in all subpopulations. The CYP2E1 polymorphism showed no association whatsoever. There is evidence that alleles are mainly dominant. In conclusion , there was heterogeneity between studies in alcoholism for ADH2, ADH3, and ALDH2, and lack of bias in all polymorphisms. The above findings reinforce the need for more rigorous studies, and for regular synthesis of studies' results. Supplementary material for this article can be found on the HEPATOLOGY website (http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html). (Hepatology 2006;43:352–361.)