Elevated Serum Lipase Levels in Patients with Dyspepsia of Unknown Cause in General Practice

<i>Objective:</i> To study the cause(s) of chronic dyspepsia among patients with no findings on general practice screening tests. <i>Materials and Methods:</i> A total of 272 consecutive patients at a general practice in Japan (125 males and 147 females, aged 14–89 years) who underwent abdominal ultrasound (US) and who had serum pancreatic enzyme (lipase or p-amylase) levels measured, were included in a 1-year study. Serum pancreatic enzyme levels were compared according to the duration of the symptoms and causes of dyspepsia, and then compared between two groups: a ‘known-cause group’ of 38 patients in whom the cause of the chronic (over 1 month) dyspepsia was determined by US or other diagnostic procedures; and an ‘unknown-cause group’ of 112 patients in whom no cause was found. <i>Results:</i> The mean lipase level in the unknown-cause group was significantly higher than that in the known-cause group (40.6 vs. 35.3 U/l, p = 0.008 after adjustment for age, sex, and serum creatinine). No difference between these groups was found for p-amylase. The proportion of patients with high lipase levels (above reference range) was higher in the unknown-cause group compared to the known-cause group, although this was not significant (21.4 vs. 10.5%). <i>Conclusion:</i> Our data showed that serum lipase levels were higher in patients with chronic dyspepsia of unknown than in those with a known cause. We therefore speculate that mild functional pancreatic disorder may underlie some cases with unexplainable chronic dyspepsia.