Clinical Implications of Hepatic Steatosis in Patients with Chronic Hepatitis C: A Multicenter Study of U.S. Veterans
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- Hu, K., Currie, S.L., Shen, H. et al. Dig Dis Sci (2007) 52: 570. doi:10.1007/s10620-006-9418-4
Studies have indicated a high prevalence of hepatic steatosis in patients with chronic hepatitis C (CHC). To address the impact of steatosis on the clinical course of CHC and treatment response requires large multicenter studies. The present study analyzed hepatitis C virus (HCV)-infected veterans enrolled in a U.S. Veteran Administration multicenter study of the epidemiology and response to interferon α-2b and ribavirin treatment. Of the 357 patients, 97.1% were males, with a mean age of 48.7±6.4 years, and 184 (51.5%) had hepatic steatosis. The mean body mass index (BMI) was 29.3±5.2 kg/m2, including 37.1% who were obese (BMI, ≥30 kg/m2). Stage III–IV fibrosis was present in 111 of 334 (33.3%) of the patients. After adjusting for age, race, and history of alcohol use in the past 12 months, only stage III–IV fibrosis was independently and significantly associated with hepatic steatosis (P=0.03). There was a trend of association between obesity and steatosis independent of the other factors. Only HCV genotype was independently associated with a sustained virological response (SVR) to interferon α-2b and ribavirin treatment after adjusting for age, alcohol use, steatosis, BMI, stage III–IV fibrosis, serum AFP, and HCV load. In conclusion, analyses of our multicenter trial data demonstrated that the prevalence of hepatic steatosis is 51.5% in HCV-infected U.S. veterans. We found that steatosis is independently associated with stage III–IV fibrosis. However, only HCV genotype, and not steatosis, obesity, or stage III–IV fibrosis, was associated with SVR to interferon α-2b and ribavirin treatment.
KeywordsHepatitis C virusChronic hepatitis CHepatic steatosisObesityBody mass indexHepatic fibrosis
Chronic hepatitis C virus (HCV) infection is estimated to affect 2.7 million individuals in the United States [1–3]. Factors that may impact disease progression, development of cirrhosis, and treatment response have been extensively studied [3–10] but are not yet completely understood. Hepatic steatosis is a common histological feature of HCV infection [11–25]. Although studies have indicated that hepatic steatosis may negatively impact the disease course and treatment response of chronic hepatitis C (CHC), these studies included small cohorts of patients from a single center [11–25]. Thus, studies of large sample size with diverse population from multicenters are needed to better define the association of steatosis with HCV disease progression and treatment response.
Factors associated with steatosis in patients with CHC can be classified by virus or host origins [24, 25]. Obesity is probably one of the most important host risk factors reported to be associated with steatosis in CHC patients [17, 24, 25]. Although many studies have found the association of HCV genotype 3 (HCV-3) infection with steatosis [12, 22, 26, 27], this was not supported by other studies [17, 19]. Whether the presence of steatosis impacts HCV treatment response remains controversial . Some [8, 18, 23], but not all  studies have suggested that steatosis may negatively affect HCV treatment response.
HCV infection is more common in U.S. veterans than the general population [28, 29]. Other potential confounding factors of steatosis such as type 2 diabetes mellitus and obesity are also common among veterans, as is alcohol use. It remains unknown whether the prevalence of hepatic steatosis in veterans is comparable to nonveterans and how steatosis affects HCV disease progression and treatment response. More than 4000 patients with CHC were enrolled in a prospective multicenter study between 1999 and 2000 at 24 Veterans Administration (VA) Medical Centers in the United States [10, 30, 31]. The aims of the current study were to determine the prevalence of and the risk factors for hepatic steatosis and to evaluate the association between steatosis and HCV treatment response in U.S. veterans with CHC.
Patients and methods
The present study was conducted through analysis of a multicenter prospective study conducted between December 1999 and December 2000 that assessed epidemiology, treatment eligibility, and interferon α-2b and ribavirin treatment response of U.S. veterans. A total of 4084 patients were recruited into the study from the gastroenterology, hepatology, and infectious disease clinics at 24 VA medical centers throughout the United States [10, 30, 31]. The study was approved by the local Institutional Review Board at each participating medical center and all subjects signed informed consent to participate.
The inclusion criteria for the present study were (1) positive HCV RNA by reverse transcription polymerase chain reaction (RT-PCR) for at least 6 months; (2) negative serology for HBsAg and anti-HIV; (3) a liver biopsy to stage CHC; (4) documented report for presence or absence of hepatic steatosis; and (5) absence of hepatic decompensation defined as the presence of ascites, jaundice (total bilirubin >3 mg/dl or 51 μmol/L), variceal bleeding, or hepatic encephalopathy . Three hundred fifty-seven of the 4084 patients met all these criteria and were included in the present study.
The original study consisted of two phases. The first phase of the study (screening phase) evaluated the epidemiology of HCV and treatment candidacy among U.S. veterans. The second phase of the study (treatment phase) determined the response to therapy in those who were subsequently treated with interferon α-2b and ribavirin . At the time of enrollment, all patients received comprehensive counseling regarding HCV disease, risk of transmission, lifestyle changes, medical prognosis, and treatment options. Patients were interviewed by trained research coordinators who obtained detailed demographic and risk factor information. Data collected on each patient included age, gender, ethnicity, era of military service, level of education, annual household income, use of alcohol, and risk factors for HCV, including blood contact during combat, blood transfusions, injection drug use, needle stick injuries, acupuncture, tattoo, body piercing, incarceration for more than 48 hr, intranasal cocaine use, and sexual history. Information on patients’ height and weight were also recorded to determine the body mass index (BMI). In accordance with the National Institutes of Health criteria, patients with a BMI between 25 and 29.9 kg/m2 were categorized as overweight, and patients with a BMI ≥30 kg/m2 were categorized as obese .
In addition, results of standard laboratory testing (complete blood count, hepatic panel, prothrombin time, electrolytes, and α-fetoprotein [AFP]), HCV RNA level, and HCV genotype were recorded on standardized data collection sheets. The presence of HCV RNA was determined using the COBAS Amplicor HCV Monitor Test version 2.0 or the COBAS Amplicor HCV Test version 2.0 (Roche Diagnostics, Branchburg, NJ), while HCV genotyping was performed using the Inno-LiPA HCV II assay (Innogenetics, Gent, Belgium). All data were entered on case report forms and faxed to a central location (Therapeias Health Management, Claremont, CA) for review and processing.
A standard course of interferon α-2b and ribavirin treatment was prescribed according to the VA Treatment Recommendations at the time of the study, which was 24 weeks for HCV genotype 2 or 3 infection and 48 weeks for all other genotypes of HCV infection. To assess the association of treatment response with steatosis, an intent-to-treat analysis (ITT) was conducted for sustained virological response (SVR), which was defined as undetectable HCV RNA 24 weeks after a full course of HCV treatment is accomplished [10, 30, 31].
All liver tissue were fixed and stained with hematoxylin–eosin and trichrome. The liver biopsy slides were reviewed by experienced pathologists at each study site using a modified Knodell scoring system to stage hepatic fibrosis [17, 33]. While stage 0 represented the absence of hepatic fibrosis, stages III–IV represented advanced hepatic fibrosis. Steatosis was reported as a dichotomous variable indicating its presence or absence.
The descriptive data were presented as percentage or mean with standard deviation or range. Median HCV RNA viral load was provided and stratified as a dichotomous variable due to variation in viral load reporting between centers. Medians for other categorical variables were also provided. Either chi-square test, Student t test, or ANOVA was used to compare frequencies or means, respectively. Univariate analyses were conducted for associations between clinical, biochemical, and virological parameters and steatosis and SVR. Multivariate analyses were then conducted using factors that were significant in the univariate analyses or that had been identified as significant in previous studies. Odds ratios and 95% confidence interval ranges were calculated using logistic regression models [17, 35, 36] to identify the clinical and biochemical/virologic parameters associated with steatosis and sustained virologic response to interferon α-2b and ribavirin treatment. A P value ≤0.05 was considered statistically significant. All statistical analyses were conducted using SAS and SPSS statistical software.
Baseline demographic findings
Baseline demographics of the 357 enrolled patients
Mean ± SD (%)
Mean age at entry
48.7 ± 6.4
49.0 (19.0–72.0) yr
History of regular alcohol
Alcohol in the past 12 months
29.3 ± 5.2
28.6 (18.6–51.0) kg/m2
1.6×106 ± 1.5×106
1×106 (1×103–5×106) copies/ml
95.9 ± 53.2
80.5 (15.0–296.0) IU/L
73.6 ± 45.9
59.0 (20.0–288.0) IU/L
199.5 ± 56.7
7.3 ± 7.2
5.0 (0.0–44.2) ng/L
Sustained virologic response
The liver biopsy showed stage 0–II fibrosis in 223 (66.4%), while 72 (21.6%) and 39 (11.7%) had stage III and IV fibrosis, respectively. In the present study, patients with stage III and IV fibrosis were combined into a group defined as having advanced fibrosis (33.6%). Of the 357 patients with histological reports on steatosis, 184 (51.5%) cases recorded the presence of hepatic steatosis.
The mean ALT, AST, and platelet count were 95.9 ± 53.2 (15.0–296.0) IU/L, 73.6 ± 45.9 (15.0–296.0) IU/L, and 199.5 ± 56.7 (79.0–361.0)×109/L, respectively. ALTs >45 IU/L and ASTs >40 IU/L were seen in 303 of 346 (87.6%) and 284 of 349 (81.4%) patients, respectively. Platelet counts <130×109/L were seen in 43 of 350 (12.3%) patients. In 294 cases who had an AFP done, the mean AFP was 7.3 ± 7.2 (0.0–44.2) μg/L, including 46 (15.7%) who had an AFP >10 μg/L. Virologically, 230 of 340 (67.7%) had HCV genotype 1 infection. The mean HCV RNA level was 1.6×106 copies/ml, and 95 of 339 (28.0%) had HCV RNA levels >2×106 copies/ml.
Parameters associated with hepatic steatosis
Univariate analysis of clinical, biochemical, and virological factors associated with hepatic steatosis
Presence of steatosis
OR (95% CI)
Alcoholic drink in past 12 mo
Drink on regular basis
Duration of alcohol history
Body mass index (BMI)
Biochemical and virological
<2.0 million copies/ml
≥2.0 million copies/ml
HCV genotype 3
Multivariate analysis of the risk factors for steatosis
Steatosis presence vs. absence
Odds ratio (95% CI)
Age (≥50 yr old)
Race (African American)
History of drinking in past 12 mo
BMI (≥30 kg/m2)
Stage III–IV fibrosis
Biochemical and virological
HCV genotype 3
HCV RNA ≥2×106 copies/ml
ALT >45 IU/L
AST >40 IU/L
AFP >10 ng/L
Univariate analysis was then used to assess six biochemical and virological parameters for their association with hepatic steatosis. As shown in Table 2 (lower panel), elevated ALT and AST and serum AFP, but not platelet counts, HCV RNA, or HCV genotype 3, were significantly associated with presence of steatosis. However, in multivariate analysis none of the five parameters, including elevated ALT, AST, and AFP, a higher HCV RNA load, and HCV genotype 3, were significantly and independently associated with steatosis (Table 3, lower panel).
Parameters associated with Sustained Virologic Response (SVR) to interferon alfa-2b and ribavirin treatment
Univariate analysis of the factors associated with a sustained virologic response (SVR)
Odds ratio (95% CI)
Alcohol use in past 12 mo
History of ≥3 drinks/day
Duration of drinking history
Fibrosis stages III–IV
Multivariate analysis of factors associated with SVR
Sustained virologic response
Odds ratio (95% CI)
Race (African American)
Alcohol in past 12 mo
BMI ≥30 kg/m2
Presence of steatosis
Presence of stage III–IV fibrosis
AFP >10 ng/L
HCV genotype 1 infection
HCV RNA ≥2×106 copies/ml
It was previously reported that the prevalence of hepatic steatosis was as high as 66% in a large cohort of U.S. patients . Data also suggest that the presence of hepatic steatosis in patients with CHC varied depending on ethnicity, BMI, and other variables of the studied population [11–23]. Our recent multicenter VA study on epidemiology and treatment of veterans with CHC [30, 31] provided us an opportunity to examine these issues. Among the 4084 patients enrolled in the National VA HCV study [30, 31], 357 qualified for the present retrospective study. The baseline demographics, including mean age, BMI, HCV genotype distribution, and history of alcohol use, were comparable to those in other studies of nonveterans [17, 22, 23], except that this cohort was predominantly male. The prevalence of hepatic steatosis in our study population was 51.5%, which is slightly lower than in U.S. nonveteran patients reported by previous single-center studies [17, 22]. Since the present study included patients from 24 geographically diverse VA medical centers, we believe that the reported prevalence may be more generalizable and better reflect the actual prevalence of steatosis in male patients with CHC in the United States.
Determining factors associated with hepatic steatosis in HCV infection will help us to understand the natural history of CHC. Among host factors, the association between obesity as determined by BMI and steatosis was found in many previous studies [11, 17, 22]. In the present study, univariate analysis of eight clinical variables suggested that BMI and race, but not age, gender, hepatic fibrosis, or alcohol history (duration, amount, and time of last drink), were associated with steatosis. Multivariate analysis indicated that stage III–IV fibrosis was independently associated with presence of steatosis (P = 0.03) and, although not statistically significant, a trend toward a significant association with BMI (P =0.06). Our results support previous single-center studies [11, 17, 22] reporting that obesity may serve as an important risk factor for steatosis in U.S. patients with CHC. Unlike some of the previous studies, we were unable to assess the degree of steatosis in this cohort study because data were only collected on the presence or absence of steatosis. It is also well known that hepatic steatosis in both HCV-infected and uninfected patients is associated with metabolic syndrome characterized by obesity, diabetes mellitus, and hypertriglyceridemia . Because the present study did not collect data on diabetes mellitus or triglyceride levels, we were unable to assess the association of diabetes mellitus and hypertriglyceridemia with hepatic steatosis.
Several studies have found an association between steatosis and progression of hepatic fibrosis in CHC patients of various ethnicities [12, 14, 21]. However, data on this issue remain limited and controversial in U.S. patients [13, 17, 19, 20, 22]. Although univariate analysis in the current study did not find an association between steatosis and hepatic fibrosis, multivariate analysis indicated that presence of steatosis was significantly associated with stage III–IV fibrosis independent of age, race, history of alcohol use in the past 12 months, and BMI. Our results support most recent reports [17, 23] that the presence of steatosis is associated with more advanced fibrosis in U.S. patients with CHC.
Alcohol use can cause hepatic steatosis. Although it was reported that a history of alcohol use may not be associated with hepatic steatosis in HCV-infected patients [11, 17, 21, 22], these data were generated from smaller, single-center cohorts. This multicenter national VA study prospectively collected detailed information regarding past and recent alcohol use [30, 31]. Thus, we were able to assess whether alcohol use serves as a risk factor for steatosis in patients with CHC. This cohort of patients included 50.7% who drank ≥3 drinks per day and almost 55.0% who had been drinking for more than 10 years. Interestingly, our data did not reveal an association between any of the alcohol factors such as a history of moderate alcohol use (≥3 drinks/day), duration (regular alcohol use for more than 10 years), or recent use (drinking in the past 12 months) with hepatic steatosis. These results confirm previous findings [11, 17, 21, 22] that a history of alcohol use may not be associated with hepatic steatosis in HCV-infected patients.
In transgenic mice, expression of HCV proteins has been associated with hepatic steatosis [38, 39]. Recent studies suggested that both HCV core and nonstructural proteins play a pathogenic role in hepatic steatosis [40, 41]. Some [12, 22, 26, 27], but not all [17, 19] studies have revealed a higher frequency and grade of hepatic steatosis in patients with HCV genotype 3 infection. A recent study indicated that effective HCV treatment is associated with reduced steatosis in patients with HCV-3 infection . Similar to the genotype distribution in the general population in the United States, we have a relatively small percentage of genotype 3 patients in our study. Based on our data, it does appear that there may be a trend (49.5% vs. 63.9%; P = 0.11) suggesting that steatosis is more common in genotype 3 patients, however, this was not statistically significant, likely due to the small sample size. There may also be other explanations. A recent in vitro study demonstrated that expression of HCV core protein derived from different patients with HCV genotype 3 infection resulted in variable degrees of steatosis in human hepatoma cells . This indicated that, besides genotype 3 infection, other factors might also play important roles in HCV-related steatosis. Additional studies will be required to elucidate the association of HCV genotype 3 infection with steatosis.
The impact of steatosis on HCV treatment response remains controversial. Some studies reported that its presence may reduce SVRs to antiviral treatment [8, 25]. Other studies did not support this notion . In our cohort, 254 patients completed a full course of HCV antiviral treatment with posttreatment follow-up to determine treatment outcome. The SVR rate (22.8%) was lower than previously reported . Univariate analysis revealed that African American race, elevated AFP, and genotype 1 infection were associated with a lower SVR rate. However, after adjusting for race, alcohol use in the past 12 months, BMI, presence of steatosis, stage III–IV fibrosis, elevated AFP, and HCV RNA load, only HCV genotype-1 was independently associated with a lower SVR rate. Thus, steatosis was not independently associated with lower SVR in our cohort of patients. It was reported that mild elevation of AFP is associated with advanced stage of fibrosis and active liver injury in HCV-infected patients . In the present study, univariate analysis suggested an association of elevated AFP with a low SVR rate. Failure to confirm this association by multivariate analysis indicated that it might be confounded by other clinical and/or biochemical variables. However, large sample studies are necessary to further elucidate this issue.
In conclusion, this study reveals a high prevalence of hepatic steatosis in HCV-infected U.S. veterans that is significantly associated with stage III–IV fibrosis and trends toward statistical significance with obesity. However, neither presence of steatosis, stage III–IV fibrosis, nor obesity was independently associated with a lower SVR to interferon α-2b and ribavirin treatment other than genotype 1 infection.
Part of this work was published as an abstract in Hepatology, Volume 38 (Supplement 1), 445A, 2003, and presented at the 54th AASLD annual meeting, November 2003, in Boston. This work was funded in part by a grant from Schering-Plough Corporation and the VA National HIV/Hepatitis C Program. We would also like to thank Roche Molecular Systems, Inc., for providing Amplicor HCV Monitor Test Kits for the study of HCV RNA testing.