Long-term outcomes in patients with gallstones detected by mass screening

Background: Gallstones are detected in about 5% of healthy Japanese. We followed up individuals showing gallstones upon screening, investigating features of those requiring surgery. Methods: In 2002 we performed health evaluations for 21,550 persons (13,986 men and 7,564 women), detecting gallstones ultrasonographically in 837 or 3.9% (561 men, or 4.0%; 276 women, or 3.6%). Up until 2012, we followed up 720 of the 837 persons with gallstones (86.0%) and compared individuals requiring or not requiring cholecystectomy as to age, gender, body mass index, diabetes, liver function, lifestyle, abdominal symptoms, and ultrasonographic findings. We also compared laboratory data obtained before and after surgery. The study was reviewed and approved by our institutional review board, and registered on UMIN-CTR (ID: UMIN000021995). Results: Among 720 persons with gallstones, 55 (7.6%) were treated by surgery. Men tended to undergo surgery more frequently than women (P = 0.086, 43 of 488, or 8%, vs. 12 of 232, or 5.2%). Need for cholecystectomy was significantly more likely among ethanol drinkers (P = 0.008). Gallstone diameters between 6 to 15 mm were more frequent in the surgical group (51.5%) than in subjects requiring only observation (29.5%; P = 0.002). Adenomyomatosis or gallbladder wall thickening was more frequent in the surgical group (P = 0.002), as was presence of abdominal symptoms (P = 0.0002). Hemoglobin A1c was significantly higher after surgery (5.4 ± 0.6) than before (5.3 ± 0.5; P = 0.001). Conclusions: Among persons with gallstones detected by screening, men who drank, had abdominal symptoms, and showed gallbladder wall thickening or adenomyomatosis were more likely to require surgery within 4 years.