Posttransplant diabetes mellitus in renal transplant patients with hepatitis C virus

Effects of preoperative hepatitis B virus infection, hepatitis C virus infection, and coinfection on the development of new-onset diabetes after kidney transplantation

BACKGROUND

The effects of preoperative hepatitis B virus (HBV) infection, hepatitis C virus (HCV) infection, and HBV plus HCV coinfection on the development of new-onset diabetes after transplantation (NODAT) remain unexplored in kidney transplant recipients (KTRs). This study examined the association between preoperative viral status (i.e., HBV, HCV, and HBC + HCV infection) and incident NODAT in a large population of Chinese KTRs.

METHODS

This population-based retrospective cohort study enrolled 557 subjects who underwent kidney transplantation between 1993 and 2014 at Zhongshan Hospital. Pre-, peri-, and postoperative data were extracted and analyzed. Viral status was defined by serological results for hepatitis B surface antigen and anti-HCV antibody. The cumulative incidence of NODAT was compared across four groups of KTRs with different viral status. Multivariate Cox regression models were used to estimate the effects of HBV, HCV, and HBC + HCV infection on incident NODAT after adjusting for important confounders.

RESULTS

Patients seropositive for HCV (both HCV monoinfection and HBC + HCV coinfection) had a significantly higher cumulative incidence of NODAT than KTRs who were not infected with HCV (P < 0.05 for both). However, only HCV infection alone was found to be a risk factor for NODAT, increasing the NODAT risk 3.03-fold (95% confidence interval 1.77-5.18; P < 0.001). There was no independent correlation between HBV infection (alone or combined with HCV) and incident NODAT in KTRs.

CONCLUSIONS

Preoperative HCV infection significantly increased the risk of NODAT in Chinese KTRs, whereas HBV infection and HBC + HCV coinfection were not correlated with NODAT development.

Risk factors for new-onset diabetes after kidney transplantation

New-onset diabetes after transplantation, a common complication following kidney transplantation, is associated with adverse patient and graft outcomes. Our understanding of the risk factors associated with this metabolic disorder is improving and both transplantation-specific and nonspecific factors are clearly involved. Knowledge of these risk factors is important so that clinicians can implement pre-emptive risk stratification strategies and to guide therapeutic, risk-attenuation approaches in patients who develop transplant-associated hyperglycemia. In this Review, we explore the current understanding of the diverse range of risk factors that contribute to abnormal glucose metabolism after transplantation, with the aim of helping to guide clinical decision-making using appropriate risk stratification.

Hepatitis C virus and type 2 diabetes

This review focuses on the relationship between hepatitis C virus (HCV) infection and glucose metabolism derangements. Cross-sectional and longitudinal studies have shown that the chronic HCV infection is associated with an increased risk of developing insulin resistance (IR) and type 2 diabetes (T2D). The direct effect of HCV on the insulin signaling has been analyzed in experimental models. Although currently available data should be considered as preliminary, HCV seems to affect glucose metabolism via mechanisms that involve cellular pathways that have been implicated in the host innate immune response. IR and T2D not only accelerate the histological and clinical progression of chronic hepatitis C, but also reduce the early and sustained virological response to interferon-alpha-based therapy. Thus, a detailed knowledge of the mechanisms underlying the HCV-associated glucose metabolism derangements is warranted, in order to improve the clinical management of chronic hepatitis C patients.

Reduced incidence of new-onset posttransplantation diabetes mellitus during the last decade

BACKGROUND

A previous study (1995-1996) of 173 nondiabetic renal transplant recipients (historical cohort; HC) revealed a 20% incidence of new-onset posttransplantation diabetes mellitus (PTDM) and 32% with impaired glucose tolerance (IGT) or impaired fasting glucose (IFG). We examined whether glucose tolerance has improved after recent changes in our immunosuppressive protocol and a switch from deferred to preemptive cytomegalovirus (CMV) therapy.

METHODS

A total of 321 consecutive, nondiabetic patients (new cohort; NC) were examined 10 weeks after kidney transplantation with an oral glucose tolerance test (n=301) between January 2004 and December 2005.

RESULTS

Although recipients in the NC were on average 3 years older [mean (SD): 50.3 (14.6) vs. 47.4 (16.0), P=0.038] and had a higher mean body mass index [24.5 (3.6) vs. 23.5 (3.8) kg/m(2), P=0.003], a significantly lower incidence of both PTDM (13%) and IGT/IFG (18%) was observed in the NC (P<0.001) as compared to the HC. The patients in the NC received a significantly lower mean daily oral prednisolone dose [13.2 (4.7) vs. 15.3 (6.6) mg/day, P<0.001], and had lower frequencies of rejections (36% vs. 57%, P<0.001) and CMV infection (54% vs. 63%, P=0.071). Patients in the NC had significantly lower odds of developing PTDM, even after adjustment for age, prednisolone dose, HLA-B27 status and CMV infection (odds ratio: 0.42, 95% CI: 0.23-0.77, P=0.005).

CONCLUSIONS

The odds of developing PTDM are more than halved over the last decade. Possible explanations are changes in immunosuppressive therapy, fewer rejections, and lower doses of steroids.

Hepatic dysfunction in kidney transplant recipients: prevalence and impact on graft and patient survival

BACKGROUND

Liver disease has emerged as an important cause of morbidity and mortality in renal transplant recipients. Liver insufficiency is the cause of death in up to 28% of long-term survivors after renal transplantation. The aim of this work was to evaluate the prevalence and causes of hepatic dysfunction in renal transplant recipients in Egypt, and its impact on both renal graft function and patient survival.

METHODS

This study comprised 447 kidney transplant recipients who received their grafts between January 1999 and December 2003 at Mansoura Urology and Nephrology Center. Among these recipients, 104 patients showed persistent hepatic dysfunction, while the remaining 343 had normal liver function or transient hepatic dysfunction of less than 6 months' duration.

RESULTS

We found that the prevalence of persistent hepatic dysfunction in our recipients was 23.3%. Infections such as hepatitis C virus (HCV;, with longer dialysis duration and blood transfusion as risk factors), HBV, and cytomegalovirus (CMV), were the main causes of persistent hepatic dysfunction. Drugs (e.g., the sirolimus and tacrolimus; cyclosporine; and azathioprine) were also associated with hepatic dysfunction. We did not find a significant impact of hepatic dysfunction on either patient or graft survival.

CONCLUSIONS

Viral infections-especially HCV and CMV-were more prevalent in the group of patients with persistent hepatic dysfunction, with duration of dialysis as an important risk factor for HCV infection. Dose-dependent cyclosporine-induced hepatic dysfunction was observed early post-transplant. Neither tacrolimus- nor sirolimus-associated hepatic dysfunction was dose-dependent. Hepatic dysfunction had no significant impact on either patient or graft survival; however, this finding may be due to the relatively short duration of follow up.

Risk Factors for Development of Posttransplant Diabetes Mellitus in Renal Transplant Recipients

Diabetes mellitus appearing after kidney transplantation--posttransplant diabetes mellitus (PTDM)--is a common complication associated with poor graft and patient survival. The purpose of the current study was to determine the risk factors for developing PTDM in 204 renal transplant recipients who had been followed for at least 30 months. Posttransplant diabetes mellitus was diagnosed according to the American Diabetic Association/WHO criteria, or a requirement for insulin, an oral hypoglycemic agent, or both. Analyses of possible risk factors for PTDM included demographic features, dialysis and posttransplantation duration, smoking, body mass index, medications, co-morbid diseases, HLA mismatches, as well as laboratory metrics of serum creatinine, albumin, calcium, phosphorus, C-reactive protein, parathyroid hormone, and lipid profiles. Twenty-six patients displayed PTDM. Univariate analysis showed that older age, greater body mass index, presence of hepatitis C virus (HCV) infection, and smoking at the time of renal transplantation were associated with PTDM development. In a multivariate analysis, HCV infection, smoking, and patient age at the time of transplantation were independent risk factors for PTDM. In conclusion, the presence of HCV infection or a smoking habit in addition to older age at the time of transplantation were the main predictors for developing PTDM. Patients should be closely followed regarding their smoking habit and weight gain as modifiable risk factors for PTDM.

Post-transplant diabetes mellitus and HCV seropositive status after renal transplantation: meta-analysis of clinical studies

Hepatitis C virus (HCV) infection has a detrimental role on patient and graft survival after renal transplantation (RT). Some studies have also implicated HCV in the development of post-transplant diabetes mellitus (PTDM). We conducted a systematic review of the published medical literature of the relationship between anti-HCV seropositive status and DM after RT. The risk of DM occurrence in anti-HCV-positive and -negative patients after RT was regarded as the most reliable outcome end-point. We used the random effects model of DerSimonian and Laird to generate a summary estimate of the Odds Ratio (OD) of new onset DM in HCV-positive and -negative patients after kidney transplantation. Ten studies involving 2502 unique RT recipients were identified. The incidence of PTDM after RT ranged between 7.9% and 50%. The summary estimate for adjusted OR was 3.97 with a 95% confidence interval (CI) of 1.83-8.61 (p-value for homogeneity <0.0473). Thus, pooling of study results demonstrated the presence of a significant link between anti-HCV seropositive status and DM after RT. This relationship provides one potential explanation for the adverse effects of HCV on patient and graft survival after RT.

Natural history of hepatitis B and C in renal allograft recipients

BACKGROUND

In renal allograft recipients, most cases of liver dysfunction are caused by hepatitis B virus and hepatitis C virus (HCV). The natural history of hepatitis C and B was studied in 286 renal allograft recipients who received a kidney allograft between 1972 and 1989 when tests for anti-HCV became available.

METHODS

In all patients, hepatitis B (HB) surface (s) antigen (Ag) was tested before and anti-HCV (by enzyme-linked immunosorbent assay II) after transplantation.

RESULTS

At enrollment in 1989 (5.5+/-4 years after transplantation), 209 patients were anti-HCV positive (C+), 42 patients were HBsAg-positive (B+), and 35 patients were both B+ and C+ (C+B+). One hundred four patients were receiving azathioprine (AZA) and 182 were on cyclosporine A (CsA). Since transplantation, the median follow-up was 18 years in AZA-treated and 13 years in CsA-treated patients. Liver biopsy showed chronic hepatitis in 73 patients, cirrhosis in 20 patients, and fibrosing cholestatic hepatitis in 2 patients. In 34 patients, liver biopsy was repeated, and progression of fibrosis was observed in 24 patients. The 12-year patient survival rate was similar in B+, C+, and B+C+ patients (67%, 78%, and 71%, respectively; P=not significant). Liver-related death was the first cause of death in B+ and B+C+ infected patients (58% and 72%, respectively), whereas cardiovascular disease was the leading cause of death in C+ patients (40%). Multivariate analysis showed that older age (>40 years) (relative risk [RR], 2.8), B+ status (RR, 2.36), and C+ status (RR, 1.65) were independently associated with a worse patient survival.

CONCLUSIONS

In the long term, B+ patients had a higher risk of death related to liver disease than C+ patients, and co-infection did not worsen patient survival.

Review article: hepatitis C virus infection and type-2 diabetes mellitus in renal diseases and transplantation

A link between hepatitis C virus infection and development of diabetes mellitus has been suggested by many investigators; however, this remains controversial. The mechanisms underlying the association between hepatitis C virus and diabetes mellitus are unclear but a great majority of clinical surveys have found a significant and independent relationship between hepatitis C virus and diabetes mellitus after renal transplantation and orthotopic liver transplantation. We have systematically reviewed the scientific literature to explore the association between hepatitis C virus and diabetes mellitus in end-stage renal disease; in addition, data on patients undergoing orthotopic liver transplantation were also analysed. The unadjusted odds ratio for developing post-transplant diabetes mellitus in hepatitis C virus-infected renal transplant recipients ranged between 1.58 and 16.5 across the published studies. The rate of anti-hepatitis C virus antibody in serum was higher among dialysis patients having diabetes mellitus (odds ratio 9.9; 95% confidence interval 2.663-32.924). Patients with type-2 diabetes-related glomerulonephritis had the highest anti-hepatitis C virus prevalence [19.5% (24/123) vs. 3.2% (73/2247); P < 0.001] in a large cohort of Japanese patients who underwent renal biopsy. The link between hepatitis C virus and diabetes mellitus may explain, in part, the detrimental role of hepatitis C virus on patient and graft survival after orthotopic liver transplantation and/or renal transplantation. Preliminary evidence suggests that anti-viral therapies prior to renal transplantation and novel immunosuppressive regimens may lower the occurrence of diabetes mellitus in hepatitis C virus-infected patients after renal transplantation. Clinical trials are under way to assess if the hepatitis C virus-linked predisposition to new onset diabetes mellitus after renal transplantation may be reduced by newer immunosuppressive medications.