Pancreatitis often caused by gallstones—also statins increase risk
Idiopathic pancreatitis is often caused by small gallstones that are difficult to observe prior to surgery, shows a study from the University of Eastern Finland. Small gallstones were found in surgery from two out of three idiopathic pancreatitis patients. The study also showed that acute pancreatitis was more common in statin users than non-users.
The main causes of acute pancreatitis in Finland are alcohol and cholelithiasis. In up to 10-20 per cent of cases, the underlying cause remains unclear. These cases may be explained by small gallstones that are not found during regular examination. A gallstone can get stuck in the junction of the common bile duct and the pancreatic duct, thus causing pancreatitis.
In a multi-centre gastrointestinal surgery study, first-time idiopathic pancreatitis patients were randomized into a surgery group and a control group.. 39 patients underwent gallbladder removal surgery, and 46 were controls. During an average follow-up of three years, pancreatitis recurred in 14 persons in the control group and in four persons in the surgery group, so recurrence was clearly more likely in controls. Similarly, there were 23 pancreatitis cases in controls and only eight in the surgery group. Small gallstones were found in surgery from two out of three patients, although not observed in repeated abdominal ultrasound prior to surgery.
This finding is important when charting the causes of idiopathic pancreatitis and courses of treatment. For instance, alcohol use may too often be suspected as the cause. The recurrence of idiopathic pancreatitis can in many cases be prevented by laparoscopic gallbladder removal surgery.
Risk of pancreatitis elevated especially during the first year of statin use
The study also analysed the association of pancreatitis with the use of cholesterol-lowering drugs, statins, as gallstones often contain crystallised cholesterol. Animal studies have shown statins to dissolve gallstones. The majority of gallstones are found in the elderly, often asymptomatic. Researchers assumed that statins may also reduce the size of gallstones in humans, enabling gallstones to travel from the gallbladder to the junction of the common bile duct and the pancreatic duct, and then manifest as pancreatitis.
In a retrospective study carried out in Kuopio University Hospital, idiopathic pancreatitis was found to be more common in statin users than in non-users. On the other hand, statin users' gallbladder removal surgery outcomes were as good as non-users', and the surgery was ten per cent faster than that of non-users. The study involved 461 acute pancreatitis patients and 1,140 cholelithiasis patients as well as a cohort of 272 statin users and 272 controls.
In a nationwide study, statin use was found to significantly increase the risk of acute pancreatitis. The risk was especially elevated during the first year of statin use. The anonymous register-based study was carried out with the Finnish Medicines Agency and involved all Finnish first cases of pancreatitis not caused by alcohol or gallstones in 2008-2010, i.e. nearly 4,500 persons, as well as nearly 25,000 controls.
"Despite these findings, no one should discontinue their statin medication without consulting their physician," says Jukka Pulkkinen, MD, who presented the results in his doctoral thesis.