Non-alcoholic fatty liver disease, alcohol intake and psoriasis
Authors: Matteo Bordignon, Guido Viel, Andrea Peserico, Mauro Alaibac
Journal: Journal of Hepatology (2010)

We read the interesting report by Gisondi et al. published in a recent issue of the Journal of Hepatology [[1]Gisondi P. Targher G. Zoppini G. Girolomoni G. Non-alcoholic fatty liver disease in patients with chronic plaque psoriasis.J Hepatol. 2009; 51: 758-764Abstract Full Text Full Text PDF PubMed Scopus (198) Google Scholar]. In this study, the authors found that patients affected by severe psoriasis exhibited an undiagnosed non-alcoholic fatty liver disease (NALFD) in almost 50% of cases and suggested that psoriasis might be a major risk factor for NALFD development. The study shed light on this important issue, but there are some concerns regarding selection of patients and the method used to measure alcohol consumption. Gisondi et al. state that the following amounts of alcoholic beverages were considered one drink: "330 ml beer (containing ∼5% of alcohol), 150 ml wine (containing ∼12% of alcohol), and 40 ml strong alcohol (containing ∼50% of alcohol)". Calculating the amount of ethanol (EtOH) of each drink, it appears that the beer contains about 13.2 g of EtOH, the wine 14.4 g and the strong alcohol about 16 g. These data indicate that the group of 33 patients consuming ⩽2 drinks had an alcohol intake of 26.4–32.0 g, depending on the type of beverages, whereas the group of 20 patients consuming 3–4 drinks had an alcohol intake of 39.6–64.0 g. Literature data have demonstrated that male patients consuming more than 30 g and female patients consuming more than 20 g of EtOH daily should be excluded from the cohort when dealing with NAFLD because it is plausible that they may already have an alcohol-related liver disease [[2]Angulo P. Nonalcoholic fatty liver disease.N Engl J Med. 2002; 346: 1221-1231Crossref PubMed Scopus (4204) Google Scholar]. Consequently, the authors should have excluded from their study the group of patients consuming 3–4 beverages/day and apply different cut-offs for males and females to include only patients fitting the above-mentioned criteria for NAFLD. Moreover, Gisondi et al. have calculated the prevalence of NAFLD in non-drinking patients (37%), which is lower compared to the psoriasis-affected population considered in their study, which include drinker and non-drinker patients. However, the prevalence of liver disease should also be calculated in light of moderate drinkers with psoriasis (consuming ⩽2 drinks and 3–4 drinks, respectively) in order to analyze the contribution of these groups in achieving a total NAFLD prevalence of 47% in psoriatic patients. Co-morbidities in psoriasis have been deeply investigated in the last years. The relationship between psoriasis and comorbi-dities is probably related to the underlying chronic inflammatory process. In this regard, emerging co-morbidities of psoriasis include cardiovascular disease and metabolic syndrome, notably obesity, dyslipidemia, and insulin resistance. Therefore, it is plausible that chronic systemic inflammation, as observed in psoriasis, may also be responsible for NAFLD [[3]Haukeland J.W. Damås J.K. Konopski Z. Løberg E.M. Haaland T. Goverud I. et al.Systemic inflammation in nonalcoholic fatty liver disease is characterized by elevated levels of CCL2.J Hepatol. 2006; 44: 1167-1174Abstract Full Text Full Text PDF PubMed Scopus (443) Google Scholar] and this association should be considered when dealing with patients affected by psoriasis, as reported by Gisondi et al. However, the prevalence of this association is probably overestimated and we believe that an accurate evaluation of the daily alcohol intake using the world-wide established alcoholic unit (corresponding to 8 g of EtOH) may improve the selection of patients in which NAFLD prevalence has to be calculated. The authors who have taken part in this study declared that they do not have anything to disclose regarding funding or conflict of interest with respect to this manuscript.