The Impact of Nonalcoholic Fatty Liver Disease and the Metabolic Syndrome on Progression of Fibrosis in Patients With Recurrent HCV After Liver Transplantation

Impact of insulin resistance on sustained response in HCV patients treated with pegylated interferon and ribavirin: a meta-analysis

BACKGROUND & AIMS

Recent studies suggested that SVR rates might be lower in HCV patients with insulin resistance (IR) than in patients without IR, but the extent of the impact of IR on treatment response has not been established. We aimed to confirm the role of IR assessed by the homoeostasis model assessment (HOMA-IR) on SVR and to determine its magnitude.

METHODS

We performed meta-analysis of studies evaluating the impact of IR in HCV patients treated with pegylated interferon and ribavirin.

RESULTS

Fourteen studies involving 2732 patients were included. SVR was less frequent in patients with IR than in patients without IR (mean difference: -19.6%, 95% CI: -29.9% to -9.4%, p<0.001). In sensitivity analyses according to HCV-1 patients, patients with IR also less frequently attained a SVR than patients without IR (mean difference: -13.0%, 95% CI: -22.6% to -3.4%, p=0.008). In addition, the baseline HOMA-IR index was lower in responders than in non-responders (mean difference: -0.92, 95% CI: -1.53 to -0.32, p<0.001). In sensitivity analyses restricted to HCV-1 patients, the baseline HOMA-IR index remained lower in responders than in non-responders (mean difference: -0.63, 95% CI: -1.13 to -0.14, p<0.001).

CONCLUSIONS

HCV patients with IR have a 20% lower SVR than patients without IR. The baseline HOMA-IR index is a major determinant of SVR.

Metabolic syndrome in liver transplantation: relation to etiology and immunosuppression

Excessive weight gain, hypertension, hyperlipidemia, and diabetes are frequently observed in patients having undergone liver transplantation (LTx). These alterations are probably multifactorial in origin, and cluster to generate a metabolic syndrome (MS), increasing the risk of cardiovascular events. We assessed the prevalence of MS (National Cholesterol Education Program-Adult Treatment Panel III criteria) in 296 LTx patients in the course of regular follow-up, at least 6 months after transplantation (median, 38 months). Several pre-LTx and post-LTx data were collected to identify the factors associated with the presence of MS. In a subset of 99 patients, insulin resistance was measured by the homeostasis model assessment. High blood pressure was present in 53% of cases, hyperlipidemia in 51%, high glucose in 37%, and enlarged waist circumference in 32%. Overall, MS (defined as 3 or more of the above features) was present in 44.5% of cases. Insulin resistance (homeostasis model assessment > 2.7) was observed in 41% of cases. Hypertension and hyperlipidemia were more frequent in subjects on cyclosporine than in tacrolimus-treated cases, whereas the type of immunosuppressive drug had no effect on the prevalence of diabetes, enlarged waist, and MS. In a logistic regression analysis, only pre-LTx body mass index (odds ratio, 1.20), body mass index increase (odds ratio, 1.18), and pre-LTx diabetes (odds ratio, 2.36) predicted MS; age, gender, etiology of liver disease, time from LTx, type of immunosuppressive drug, and previous hepatocellular carcinoma were removed from the model. Disorders related to MS are frequent in LTx patients, and are related to both pre-LTx conditions and to weight gain. Weight control is mandatory in LTx patients to prevent risk factors of premature atherosclerosis.

Transplant-associated hyperglycemia

As patient survival after solid organ transplantation continues to improve, comorbidites associated with chronic hyperglycemia will assume increasing importance in limiting outcomes and quality of life. New-onset diabetes mellitus commonly occurs in the posttransplant setting and is associated with multiple complications including graft loss, cardiovascular disease, infection, and death. Furthermore, recent studies have begun to highlight the very high posttransplant prevalence and the significant cardiovascular implications of the prediabetic states of impaired fasting glucose and impaired glucose tolerance, indicating that the overall burden of transplantation-associated hyperglycemia is far greater than previously appreciated. Shared and distinct pathogenic factors and clinical repercussions exist among the organ-specific transplant scenarios. Diabetogenic immunosuppressive agents are common to all organ transplant settings, whereas glucose regulation is also strained by the restoration of failed hepatic and renal function. The atherogenic properties of hyperglycemia are particularly significant in the kidney transplant population, which has a marked predisposition to cardiovascular disease, whereas accelerated cardiac allograft vasculopathy and liver fibrosis have been associated with hyperglycemia in the heart and liver transplant settings, respectively. Aggressive screening will effectively detect transplant-associated hyperglycemia, whereas risk factor modification, lifestyle intervention and, where appropriate, drug therapy, may decrease its impact. Topics of future investigation should include the use of emerging diabetes therapies and avenues for the prevention and reversal of transplant-associated hyperglycemia.

Male hypogonadism in cirrhosis and after liver transplantation

Liver is deeply involved in the metabolism of proteins, hormones, enzymes, cytokines, as well as in sex hormones catabolism. Gonadal function requires a normal liver function, and it is well known that clinical signs of hypogonadism are common in patients with liver cirrhosis. Few studies have focused on hypothalamic- pituitary-gonadal alterations in male cirrhotic patients or after orthotopic liver transplantation (OLT). The pathogenesis of hypogonadism in cirrhotic patients is complex and not well explained. It involves both a gonadal and a hypothalamic- pituitary dysfunction. After OLT the hypothalamic-pituitary-gonadal function partially improves, showing that the hepatic dysfunction before OLT is deeply involved in its pathogenesis. After OLT some alterations persist in some patients, both because of pre-existing gonadal alterations (toxic-metabolic damage) and immunosuppressive pharmacological side effects. Further studies will explain the relationship between hypogonadism and OLT outcome, and the role of androgen therapy in hypogonadism after OLT, in the early months and in the long term.

Hepatitis C virus and liver transplantation

Hepatitis C virus (HCV) infection remains the most common cause of hepatic failure requiring orthotopic liver transplantation, and the disparity between the number of patients in need of liver replacement and the number of organs available continues to grow. Unfortunately, without viral eradication before transplantation, HCV recurrence is universal and is associated with poor graft and patient survival. Despite expansion of the donor pool and attempts to suppress HCV activity with various pretransplant and posttransplant antiviral therapies, many questions remain. This article reviews the literature regarding the evaluation of patients for transplantation, the antiviral therapies available in the peritransplant period, the immunosuppressive regimens, used, and the approach to patients with recurrent HCV infection.