Background & Aim Histologic analysis of liver biopsies allows for grading and staging of nonalcoholic fatty liver disease (NAFLD). We performed a longitudinal study to investigate the long-term prognostic relevance of histologic features for patients with NAFLD. Methods We performed a retrospective analysis of 619 patients diagnosed with NAFLD from 1975 through 2005 at medical centers in the United States, Europe, and Thailand. Patients underwent laboratory and biopsy analyses, and were examined every 3–12 months after their diagnosis. Outcomes analyzed were overall mortality, liver transplantation, and liver-related events. Cumulative outcomes were compared by log-rank analysis. Cox proportional-hazards regression was used to estimate adjusted hazard ratios (HR). Time at risk was determined from the date of liver biopsy to the date of outcome or last follow-up examination. Results Over a median follow-up of 12.6 years (range 0.3–35.1), 193 of the patients (33.2%) died or underwent liver transplantation. Features of liver biopsies significantly associated with death or liver transplantation included fibrosis stage 1 (HR, 1.88; 95% CI, 1.28, 2.77), stage 2 (HR, 2.89; 95% CI, 1.93, 4.33), stage 3 (HR, 3.76; 95% CI, 2.40, 5.89), and stage 4 (HR, 10.9; 95% CI, 6.06, 19.62) compared with stage 0, as well as age (HR, 1.07; 95% CI, 1.05, 1.08), diabetes (HR, 1.61; 95% CI, 1.13, 2.30), current smoking (HR, 2.62; 95% CI, 1.67, 4.10) and statin use (HR, 0.32; 95% CI, 0.14, 0.70). Twenty-six patients (4.2%) developed liver-related events; fibrosis stage 3 (HR 14.2 [95% CI 3.38, 59.68]) and stage 4 (HR 51.5 [95% CI 9.87, 269.2]) compared to stage 0, were significantly associated with the events. Patients with fibrosis, regardless of steatohepatitis or NAFLD activity score, had shorter survival times than patients without fibrosis. Conclusions In a longitudinal study of patients with NAFLD, fibrosis stage, but no other histologic features of steatohepatitis, were independently associated with long-term overall mortality, liver transplantation, and liver-related events.

In a systematic review and meta-analysis, Giovanni Musso and colleagues examine the association between non-alcoholic fatty liver disease and chronic kidney disease. Please see later in the article for the Editors' Summary

BACKGROUND & AIMS Some patients with nonalcoholic fatty liver disease (NAFLD) develop liver-related complications and have higher mortality than other patients with NAFLD. We determined the accuracy of simple, noninvasive scoring systems in identification of patients at increased risk for liver-related complications or death. METHODS We performed a retrospective, international, multicenter cohort study of 320 patients diagnosed with NAFLD, based on liver biopsy analysis through 2002 and followed through 2011. Patients were assigned to mild-, intermediate-, or high-risk groups based on cutoff values for 2 of the following: NAFLD fibrosis score, aspartate aminotransferase/platelet ratio index, FIB-4 score, and BARD score. Outcomes included liver-related complications and death or liver transplantation. We used multivariate Cox proportional hazard regression analysis to adjust for relevant variables and calculate adjusted hazard ratios (aHRs). RESULTS During a median follow-up period of 104.8 months (range, 3–317 months), 14% of patients developed liver-related events and 13% died or underwent liver transplantation. The aHRs for liver-related events in the intermediate-risk and high-risk groups, compared with the low-risk group, were 7.7 (95% confidence interval [CI]: 1.4–42.7) and 34.2 (95% CI: 6.5–180.1), respectively, based on NAFLD fibrosis score; 8.8 (95% CI: 1.1–67.3) and 20.9 (95% CI: 2.6–165.3) based on the aspartate aminotransferase/platelet ratio index; and 6.2 (95% CI: 1.4–27.2) and 6.6 (95% CI: 1.4–31.1) based on the BARD score. The aHRs for death or liver transplantation in the intermediate-risk and high-risk groups compared with the low-risk group were 4.2 (95% CI: 1.3–13.8) and 9.8 (95% CI: 2.7–35.3), respectively, based on the NAFLD fibrosis scores. Based on aspartate aminotransferase/platelet ratio index and FIB-4 score, only the high-risk group had a greater risk of death or liver transplantation (aHR = 3.1; 95% CI: 1.1–8.4 and aHR = 6.6; 95% CI: 2.3–20.4, respectively). CONCLUSIONS Simple noninvasive scoring systems help identify patients with NAFLD who are at increased risk for liver-related complications or death. NAFLD fibrosis score appears to be the best indicator of patients at risk, based on HRs. The results of this study require external validation.

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BackgroundFew studies have compared the prognosis and liver-related mortality in patients with NAFLD (nonalcoholic fatty liver disease) and AFLD (alcoholic fatty liver disease). We aimed to investigate the etiology and liver-related mortality of patients with liver biopsy verified fatty liver disease in a population based setting.MethodsIn this retrospective study, all patients who underwent a liver biopsy 1984–2009 at the National University Hospital of Iceland were identified through a computerized pathological database with the code for fatty liver. Only patients with NAFLD and AFLD were included and medical records reviewed. The patients were linked to the Hospital Discharge Register, the Causes of Death Registry and Centre for Addiction Medicine.ResultsA total of 151 had NAFLD and 94 AFLD with median survival of 24 years and 20 years, respectively (p = NS). A total of 10/151 (7%) patients developed cirrhosis in the NAFLD group and 19/94 (20%) in AFLD group (p = 0.03). The most common cause of death in the NAFLD group was cardiovascular disease (48%). Liver disease was the most common cause of death in the AFLD group (36%), whereas liver-related death occurred in 7% of the NAFLD group. The mean liver-related death rate among the general population during the study period was 0.1% of all deaths. There was a significantly worse survival for patients in the AFLD group compared to the NAFLD group after adjusting for gender, calendar year of diagnosis and age at diagnosis (HR 2.16, p = 0.009). The survival for patients with moderate to severe fibrosis was significantly worse than for patients with mild fibrosis after adjusting for gender, calendar year of diagnosis and age at diagnosis (HR 2.09, p = 0.01).ConclusionsPatients with fatty liver disease showed a markedly higher risk of developing liver-related death compared to the general population. The AFLD group had higher liver-related mortality and had a worse survival than the NAFLD group. Patients with more severe fibrosis at baseline showed a worse survival than patients with none or mild fibrosis at baseline.