Reuters Health Information (2011-01-12): Metabolic syndrome common after liver transplant
Metabolic syndrome common after liver transplant
Last Updated: 2011-01-12 18:52:14 -0400 (Reuters Health)
NEW YORK (Reuters Health) - Metabolic syndrome is at least twice as common in long-term survivors of liver transplantation as it is in the general public, according to a study scheduled for publication in the January issue of Liver Transplantation.
The researchers saw an association between post-transplant metabolic syndrome (PTMS) and cardiovascular morbidity, but not mortality.
Metabolic abnormalities are "almost universal" after liver transplant, according to senior author Dr. Ziv Ben Ari of the Rabin Medical Center at Beilinson Hospital in Petah Tiqwa, Israel and his colleagues.
They're not the only ones saying that these days. An article published in the same journal in December 2009 by Pagdala et al called metabolic syndrome after liver transplantation "an epidemic waiting to happen."
The problem has been attributed as least in part to side effects from immunosuppressant drugs, which include diabetes, high cholesterol, and high triglycerides. In addition, technical improvements in the surgery and in pre- and post-operative care have been allowing liver recipients to grow old.
Today, long-term graft loss and death after liver transplantation are commonly related to age-related complications. According to Dr. Ben Ari and his team, cardiovascular disease is now the main cause of non-graft related mortality in these patients, and particularly in the older individuals.
To analyze their own center's experience, the researchers looked at medical records for 248 patients who had liver transplantation between 1991 and 2007 at their center and were followed for six months or longer, as well as four patients who received liver transplants elsewhere between 1985 and 1991. Most patients received tacrolimus or cyclosporine, along with mycophenolate mofetil and corticosteroids tapered within 6 months after transplant.
Among the 221 patients for whom pre-transplant data were adequate for assessment, 5.4% had metabolic syndrome. On posttransplant assessments, 51.9% of the 252 patients had metabolic syndrome.
Overall, obesity, hypertriglyceridemia, HDL cholesterol below 40 mg/dL, dyslipidemia, hypertension, and diabetes were all more frequent after transplant.
Patients undergoing transplantation for hepatitis C infection or cryptogenic cirrhosis were significantly more likely to develop post-transplant metabolic syndrome. There was no link between biliary diseases, autoimmune hepatitis, or hepatitis B infection and metabolic syndrome.
While immunosuppression overall wasn't linked to the development of metabolic syndrome, the researchers did find that use of tacrolimus or cyclosporine predicted posttransplant hypertension and hypertriglyceridemia.
Multivariate analysis identified older age, metabolic derangement, and cryptogenic cirrhosis as independent pre-transplant predictors of metabolic syndrome later on -- along with pre-transplant non-alcoholic fatty liver disease and diabetes.
The link between cryptogenic cirrhosis and increased risk could be because many patients may actually have unrecognized non-alcoholic steatohepatitis, Dr. Ben Ari and his team suggest.
Thirteen percent of the patients with post-transplant metabolic syndrome had major vascular events, compared to 5% of patients without it (p=0.027).
Post-transplant metabolic syndrome did not increase the risk of mortality, however (19% of affected patients died during follow-up, compared to 17.3% of patients without metabolic syndrome). Only one death was due to an acute coronary event.
The current findings don't support a role for immunosuppressant drugs in this condition, the researchers add.
"It is possible that other factors predispose liver transplant recipients" to metabolic syndrome, such as "the return to normal daily life and free food intake, together with normalization of the hypermetabolic state of advanced liver diseases, which can contribute to weight gain...; changes in lipoprotein metabolism induced by the new liver; and the underlying liver disease itself."
In an editorial, Dr. Sanjaya K. Satapathy and Dr. Michael Charlton of the Mayo Clinic in Rochester, Minnesota, argue that metabolic syndrome that develops after liver transplantation is likely to be modifiable.
"Screening, prevention and treatment strategies, e.g. with nutritional counseling, lipid-lowering therapy, optimal control of hypertension, and choosing immunosuppressants that would (be) less likely to cause (metabolic syndrome) are needed," they write.
In the meantime, they say, we have an "urgent need for studies of the impact of more aggressive recourse to early diagnosis and sustained implementation of interventions for prevention, diagnosis and treatment" of posttransplant metabolic syndrome.
Liver Transpl 2011.