[High lactose content of the Lundh test meal adversely affects the reliability of the ALTAB test]

The exocrine pancreatic function was examined in 20 patient without any detectable gastrointestinal disorder. We used 1 g 4(N-acetyl-L-thyrosil) aminobenzoic acid (ALTAB) an Lundh's test meal containing 25 g lactose, and the test was repeated with 3 g lactase (Galantase). The urine was collected for 6 hours to check PABA excretion in urine. Lactose intolerance was diagnosed in 10 patients on the basis of an increase of H2 in the breath at least 15 ppm after Lundh's test meal and/or diarrhoea after test in two hours if this diarrhoea could be prevented by giving Galantase orally. We measured PABA excretion in patients with and without lactose intolerance after Lundh's test meal: 17.8% (SD = 6.7) and 47% (SD = 13) respectively (p less than 0.001), and after Lundh's test meal with Galantase: 34.3% (SD = 12.7) and 43.6% (SD = 10.9) respectively. The increase after Galantase in the group with lactose intolerance was significant (p less than 0.01).

1. Lactose content of Lundh's test meal causes a considerable lactose load in patients with lactose intolerance. 2. Oral lactase enzyme usually normalises the result of ALTAB test. 3. It is necessary to detect lactose intolerance before use of Lundh's test meal.