In findings published in the Canadian Medical Association Journal, researchers from the Karolinska Institute in Stockholm found current or previous HRT users were 1.5 more likely to suffer acute pancreatitis than those who had never used the therapy.
 

"There are no contemporary data that might explain our finding that the risk was sustained among past users of [HRT] or that the risk seemed to increase with duration of use," said researcher Viktor Oskarsson, M.D. "These findings, though speculative, may suggest that exogenous estrogen induces some persistent change in the pancreas for which the duration of exposure may be important."
 

Pancreatitis, a sudden inflammation of the pancreas, has symptoms that range from mild discomfort to severe, debilitating pain, and can even lead to death.
 

For the study, the researchers examined the medical records of 31,494 Swedish postmenopausal women between 1997 and 2010. About 42 percent of the women were current users of HRT, 12 percent were previous users, and the remainder had never used the therapy.
 

In addition to finding women who currently or previously had used HRT were far more likely to suffer acute pancreatitis, the results also showed the risk was higher among women who used systemic therapy and had taken the hormone treatment more than 10 years.