The Evolution of Iron-Related Comorbidities and Hospitalization in Patients with Hemochromatosis: An Analysis of the Nationwide Inpatient Sample

Abstract

Hemochromatosis, either hereditary hemochromatosis (HH) or secondary hemochromatosis, consists of the accumulation of iron in the liver, heart, and other organs. It leads to end-organ damage in a proportion of affected subjects. Although liver-related morbidity (cirrhosis and hepatocellular carcinoma [HCC]) and mortality are well established, the frequency of these complications remains controversial. The aim of this study is to examine the rate of hospitalization and the incidence of iron overload-related comorbidities in patients with hemochromatosis between the years of 2002 and 2010. We queried the Nationwide Inpatient Sample (NIS) database from the year 2002 to 2010. We included adults (age ≥18 years) and used the ICD-CM 9 code 275.0x to identify hospitalized patients with a diagnosis of hemochromatosis. Data analysis for this study was generated using SAS software version 9.4. A total of 168,614 hospitalized patients between 2002 and 2010 had a diagnosis of hemochromatosis. The majority were males (57%) with a median age of 54 years (37–68), with a predominance of white patients (63.3%) followed by black (26.8%). The rate of hospitalization among patients with hemochromatosis increased by 79% between the years 2002 and 2010 (34.5/100,000 in 2002 vs 61.4/100,000 in 2010). The main associated diagnoses were diabetes mellitus (20.2%), cardiac disease, including arrhythmias (14%) and cardiomyopathy (dilated 3.8%; peri-, endo-, myocarditis 1.3%), liver cirrhosis (8.6%), HCC (1.6%), and acute liver failure (0.81%). Of note, HCC was associated with cirrhosis in 1188 patients (43% of HCC patients) and male sex (87%). Diagnostic biopsies were performed in 6023 (3.6%) of those patients and liver transplant was performed in 881 (0.5%). In-hospital mortality occurred in 3638 (2.16%) patients. In this large database study, we found a rising trend in hospitalization for hemochromatosis, possibly due to the increased recognition of this entity and billing for the condition. The incidence of cirrhosis in hemochromatosis was found to be similar to other studies (8.6% vs 9%). However, the rate of HCC was lower than previous reports (1.6% vs 2.2%–14.9%), and only 43% of HCC was associated with cirrhosis. This raises important pathophysiologic questions regarding the impact of iron overload in HCC. There has been an increase in the rate of hospitalization for patients with a diagnosis of hemochromatosis. This may be related to an increased recognition of hemochromatosis as the underlying etiology for conditions such as diabetes, cardiomyopathy, cirrhosis, and HCC. Further prospective studies are needed to clarify the burden of liver disease in HH and secondary iron overload.