The Role of Non-Alcoholic Fatty Liver Disease in Acute Pancreatitis Patients: A Propensity-Matched Study

Abstract

Introduction: Non-alcoholic fatty liver disease (NAFLD) is an emerging liver disease over the last decades. Its role in Acute Pancreatitis (AP) has not been established. Our aim is to examine the role of NAFLD in outcomes of hospitalized AP patients. Methods: We utilized the Nationwide Inpatient Sample (NIS) database from 2003 to 2012 to identify patients diagnosed with Acute Pancreatitis (577.0 in DX1-DX3) using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes, after excluding cases with missing data on age, gender or inpatient mortality. Among this cohort, NAFLD (571.8) was identified while excluding other confounding diseases such as cirrhosis, alcoholism, viral hepatitis, and metabolic liver disorders. Extracted hospitalization complications included systemic inflammatory response syndrome (SIRS), sepsis, septic shock, electrolyte imbalance, acute renal injury, acute respiratory failure. Trends were tested with survey-weighted regressions while adjusting for Charlson score and hospital-level variables. NAFLD, together with the variables above, were regressed against inpatient mortality, LOS and hospitalization costs, using multivariable mixed-model regressions. The above analyses were repeated with propensity-matching, that also included the AP etiology, to better isolate the NAFLD effect. Results: A total of 61,630 patients (1.78%) had NAFLD in the AP population from 2003-2012. Mean age of the NAFLD cohort was 50.1 years; 51% were females and 66.3% whites. NAFLD patients had a mean LOS 5.3 days and mean hospitalization costs $11,080, while the non-NAFLD group had a significantly (p < 0.001) longer LOS (12.5 days) and higher costs ($12,105). Inpatient mortality was lower (p < 0.001) in the NAFLD group (0.37%), compared to 1.39% in the non-NAFLD group. Prevalence of NAFLD increased by 3.5 times (0.78% to 2.73%; p < 0.001, Figure 1). Mean costs in NAFLD patients did not show any significant trend. LOS also demonstrated a decreasing trend in both subgroups. NAFLD was not associated with increased inpatient mortality (Odds Ratio [OR]=0.34, p < 0.001; propensity-matched OR [pmOR]=0.49, p < 0.001). NAFLD was associated with slightly shorter LOS (OR=0.96, p < 0.001; pmOR=0.93, p < 0.001), without affecting costs (Figure 2).FigureConclusion: NALFD has tripled over the last decade in AP patients and was not associated with increased mortality among these patients, regardless of etiology, comorbidities or hospitalization complications.Table: No Caption available