According to a new meta-analysis, patients with autosomal dominant polycystic kidney disease (ADPKD) are more likely to develop diabetes following kidney transplantation.

The analysis was carried out by researchers at the Mayo Clinic who looked at 12 separate studies to determine the risk of ADPKD patients developing diabetes following kidney transplant. Results were presented in a poster presentation at an April meeting of the National Kidney Foundation.

According to Dr. Wisit Cheungpasitporn, the risk ratio of new onset diabetes following transplantation was 1.92 (95 percent CI, 1.36-2.70). However, some of the studies did not control for confounders. When those studies were excluded, the risk ratio increased to 1.98 (95 percent CI, 1.33-2.94).

"The findings of this study may impact clinical management and follow-up for ADPKD patients after kidney transplantation," the researchers wrote in the analysis.

While the link between ADPKD and new-onset diabetes following transplantation isn't clear, the number of cases of new-onset diabetes after transplant is increasing. The incidence in these patients range from 7 to 46 percent.

"It has been proposed that insulin resistance genes co-transmitted with polycystic kidney disease 1 and polycystic kidney disease 2 mutations may interfere with insulin secretion and hepatic gluconeogenesis," the authors wrote.

Additionally, ADPKD patients who have normal kidney function also have increased insulin resistance, evidence suggests.

In the analysis, researchers looked at a total of 9,849 patients who had undergone kidney transplantation, 1,379 of whom had ADPKD. The only studies that were included reported relative risk, odd ratio or hazard ratios for the risk of new-onset diabetes following transplantation in patients with ADPKD.

They pointed out that other risk factors for developing diabetes after transplantation include:

  • Obesity
  • Hepatitis C
  • Cytomegalovirus infection
  • Impaired fasting glucose
  • Ethnicity
  • Patients using corticosteroids or calcineurin inhibitors

Cheungpasitporn said the studies analyzed included a lack of causation. Therefore, it's not clear what actually causes the cases of new-onset diabetes following transplantation; it's just clear that the risk increases. Researchers suggested the transplant could affect insulin in such a way that these patients become insulin resistant instead of insulin deficient.

"Since we found a significant association, the next step is how to meaningfully address the clinical implications in the future — how to catch early, how to prevent early, and how to reduce risk of diabetes," Cheungpasitporn said.

Dr. Nwamaka Eneanya of Boston's Massachusetts General Hospital said the study was a great look at a highly specific patient population.

"Yes, their kidney function may be normal after transplantation, but we know they have a genetic predisposition to developing diabetes," he said.

Other doctors say the study's results don't indicate a need to change clinical management of patients with AKPKD.

"The unfortunate truth is that the majority of patients with ADPKD will ultimately progress to end-stage renal disease and require renal replacement therapy," said Dr. Joel Topf, a physician at St. Clair Nephrology in Detroit who was not involved in the study. "New-onset diabetes after transplantation is a too common complication of transplant, and telling me that a patient has a higher likelihood of developing this complication is not going to change the reality that transplant is the best treatment for renal failure."