Impact of steatosis on insulin secretion in chronic hepatitis C patients

Steatosis degree, measured by morphometry, is linked to other liver lesions and metabolic syndrome components in patients with NAFLD

BACKGROUND AND AIM

We carried out morphometric measurements of steatosis to evaluate relationships between steatosis degree and other liver lesions or metabolic syndrome components in nonalcoholic fatty liver disease (NAFLD).

PATIENTS AND METHODS

We developed an algorithm to measure steatosis area. Two hundred and fourteen patients with NAFLD were included in derivation (10) and validation (204) groups. Controls consisted of patients who were steatosis-free (12), patients with chronic hepatitis C (188), and patients with alcoholic chronic liver disease (94).

RESULTS

Accuracy of steatosis area was considered as good or very good in at least 72% of cases by three pathologists. Steatosis areas were as follows: NAFLD = 10.3 ± 9.7%, virus = 2.4 ± 3.1%, alcohol = 7.8 ± 8.2% (P<0.0001). Steatosis area was closely related to steatosis grades in NAFLD (P<0.0001 for linear trend). Steatosis area increased from the fibrosis stage F0 to the fibrosis state F2, then decreased in the stages F3 and F4 (cirrhosis) (P<0.0001 for quadratic trend). Fibrosis was present in an average steatosis area of approximately 4% (defining significant steatosis) and in nonalcoholic steatohepatitis by approximately 8% (defining severe steatosis). Steatosis and fibrosis area increased symmetrically until approximately 10%, then steatosis area decreased to null as average fibrosis area reached 32%. Average fasting glycemia (approximately 92 mg/dl) or triglycerides and BMI plateaued before a steatosis area of approximately 4%, then increased thereafter. Significant steatosis was present in 61.3% of NAFLD versus 20.2% of viral hepatitis (P<0.0001) and in 58.7% of alcoholic liver diseases (P=0.674).

CONCLUSIONS

The average threshold of steatosis area is 4% for the development of fibrosis or metabolic syndrome components and 8% for nonalcoholic steatohepatitis. Steatosis area may contribute to defining the normal range and clinical course of metabolic components.

Change of insulin sensitivity in hepatitis C patients with normal insulin sensitivity: a 5-year prospective follow-up study variation of insulin sensitivity in HCV patients

BACKGROUND

Hepatitis C virus (HCV) infection is associated with a high prevalence of diabetes mellitus (DM). Insulin resistance (IR) is known to play a crucial role in the development of DM in chronic hepatitis C (CHC) patients. We prospectively investigated changes of insulin sensitivity in CHC patients during a 5-year period and analysed the factors significantly associated with IR.

METHODS

Sixty-two CHC patients with normal insulin sensitivity (CHC group), and a healthy control group of 172 subjects matched by age, gender, body mass index and lifestyles were studied. We compared the initial baseline insulin sensitivity, metabolic parameters and incidence of IR at the end of the follow-up period between the two groups. The changes in insulin sensitivity, metabolic parameters and the development of IR were analysed as well as factors associated with the development of IR.

RESULTS

IR developed in 22.5% of 62 CHC patients and 5.2% of 172 normal individuals (P < 0.001). HCV infection per se and the genotype 1 were independent risk factors for the development of IR. The duration of infection > or = 120 months, initial fasting glucose 90-100 mg/dL, fasting insulin > or = 10 microIU/mL and the homeostasis model assessment (HOMA-IR) 2.3-2.7 were significantly associated with the development of IR in the CHC group.

CONCLUSION

HCV infection was an independent risk factor for the development of IR. All CHC patients, even those with normal insulin sensitivity, require careful monitoring for the development of IR.

Host genetics, steatosis and insulin resistance among African Americans and Caucasian Americans with hepatitis C virus genotype-1 infection

Hepatic steatosis is the accumulation of fat in liver cells. Insulin resistance (IR) occurs when normal amounts of insulin do not stimulate insulin activity in cells. Both conditions have been described in hepatitis C virus (HCV) infection and are thought to be biologically related. This study examined the association of genetic variants with steatosis and IR among 167 African Americans and 184 Caucasian Americans with HCV genotype-1. Steatosis was defined as at least 5% of fat in cells on liver biopsy. IR was quantified as a score greater than 2 from the Homeostasis Model Assessment, version 2.2 (HOMA2-IR). Associations were investigated by estimating odds ratios separately by race. Statistically significant associations (p < 0.05) were observed for variants in interleukin-10 (IL10), leptin receptor (LEPR), interleukin-6 (IL6) and transforming growth factor beta-1 (TGF-beta1) for both outcomes. Some significant interactions were observed between IL10,LEPR and TGF-beta1 polymorphisms and HOMA2-IR scores when examining steatosis. The interaction of HOMA2-IR and IL10 was consistent in both races whereas for LEPR and TGF-beta1 the interactions were statistically significant in only one of the racial groups.These results could imply that some IL10,LEPR and TGF-beta1 polymorphisms may modify an association between steatosis and IR.

Assessment of hepatic steatosis: comparison of quantitative and semiquantitative methods in 108 liver biopsies

BACKGROUND

There is growing interest in the role of hepatic steatosis in liver injury. The current standard for steatosis assessment is histological grading, although there is variability in the scoring systems used.

AIMS

The aim of this study was to compare steatosis assessment by image analysis and histological grading.

METHODS

Three methods were used to measure steatosis: histological grading (from 0 to 4); estimation of the percentage of hepatocytes (to nearest 5%) with steatosis; and computer-assisted image analysis. Image analysis was performed on multiple fields for each biopsy with image pro plus 4.5, with steatotic droplets identified on the basis of shape, colour and size. Computer-selected objects were reviewed to ensure that these were steatotic droplets. The predictive accuracy of the three techniques was assessed using measures of obesity and insulin resistance (homeostasis model assessment) as the outcome variables.

RESULTS

There was a strong correlation between the results of image analysis and histological grade (r(s)=0.89, P<0.01), and estimated per cent steatosis (r(s)=0.93, P<0.01). The variability in the area of steatosis calculated by image analysis in different fields of a biopsy correlated with the total steatosis area (r(s)=0.93, P<0.01).

CONCLUSIONS

Image analysis did not offer any additional predictive value when the association between degree of obesity or insulin resistance was correlated with the different methods of assessing steatosis. Image analysis allows measurement of area of steatosis in liver biopsy material and generates a continuous variable that facilitates statistical analysis. These aspects may prove beneficial in research settings.

Insulin resistance and hepatitis C virus: a case-control study of non-obese, non-alcoholic and non-steatotic hepatitis virus carriers with persistently normal serum aminotransferase

BACKGROUND/AIMS

Recent studies using transgenic mouse models have demonstrated that the presence of hepatitis C virus (HCV) singularly induces insulin resistance (IR). When evaluated in humans, the exclusion of other factors influencing IR, such as obesity, alcohol intake, hepatic inflammation and steatosis is needed, but only few studies have been performed to these ends. Therefore, we aimed at exploring the singular effects of HCV on glucose metabolism through analysis of HCV carriers with persistently normal serum aminotransferase.

METHODS

Non-obese, non-diabetic and non-alcoholic HCV carriers (n=30) were enrolled with 30 hepatitis B virus carriers matched by age, gender, body mass index and waist-to-hip ratio. All patients maintained normal serum aminotransferase (<30 U/L), hyaluronic acid (<50 ng/ml) and platelet count (>150 x 10(3)/microl) for more than 5 years without additional treatments, and had no signs of steatosis. We then compared fasting plasma glucose, serum insulin and adiponectin, and homoeostasis model assessment of IR (HOMA-IR) and HOMA-beta indices between the groups.

RESULTS

There were no significant differences in IR/secretion-associated markers or serum adiponectin. Multivariate analysis demonstrated that the presence of HCV was not an independent predictor of IR. HOMA-IR was strongly correlated with waist circumferences and serum gamma-glutamyltransferase in HCV carriers, but not with serum aminotransferase, high-sensitivity C-reactive protein, hyaluronic acid or HCV core antigen.

CONCLUSIONS

These results suggest that the presence of HCV alone does not affect IR. Coexistence of hepatitis, steatosis and/or fibrosis may be important to the pathogenesis of IR induced by chronic HCV infection.

Treatment responses in Asians and Caucasians with chronic hepatitis C infection

AIM: To conduct a multicentre retrospective review of virological response rates in Asians infected with genotype 1 chronic hepatitis C (CHC) treated with combination interferon and ribavirin and then to compare their responses to that among Caucasians.

METHODS: Asian patients infected with genotype 1 CHC treated at 4 Australian centres between 2001 to 2005 were identified through hospital databases. Baseline demographic characteristics, biochemical, virological and histological data and details of treatment were collected. Sustained virological responses (SVR) in this cohort were then compared to that in Caucasian subjects, matched by genotype, age, gender and the stage of hepatic fibrosis.

RESULTS: A total of 108 Asians with genotype 1 CHC were identified. The end of treatment response (ETR) for the cohort was 79% while the SVR was 67%. Due to the relatively advanced age of the Asian cohort, only sixty-four subjects could be matched with Caucasians. The ETR among matched Asians and Caucasians was 81% and 56% respectively (P = 0.003), while the SVR rates were 73% and 36% (P < 0.001) respectively. This difference remained significant after adjusting for other predictive variables.

CONCLUSION: Genotype 1 CHC in Asian subjects is associated with higher rates of virological response compared to that in Caucasians.