Elevated serum lipase levels in patients with dyspepsia of unknown cause in general practice.

OBJECTIVE To study the cause(s) of chronic dyspepsia among patients with no findings on general practice screening tests. MATERIALS AND METHODS 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. RESULTS 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%). CONCLUSION 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.