Isolated Lactase Deficiency Producing Postgastrectomy Milk Intolerance

Abstract

Twenty-four patients who had undergone various surgical procedures for peptic ulcer disease had lactose tolerance tests. Nineteen absorbed lactose normally and had a mean maximum blood sugar increase over fasting levels of 110 mg/100 ml (range: 38-191 mg/100 ml). Twenty-three intestinal specimens from 13 of this group were assayed and the mean intestinal lactase activity was 42 units /g protein (range: 16-82 units). The 5 other patients had abnormal absorption of lactose with a mean blood sugar increase of 14 mg/100 ml (range: 11-19 mg/100 ml). The mean intestinal lactase activity in 9 specimens from these 5 patients was 6 units /g protein (range: 4-8 units). The sucrase, maltase, palatlnase and alkaline phosphatase activities were similar in the 2 groups. The isolated lactase deficiency leading to milk intolerance In the 5 patients could not be attributed to differences in the type of surgery. Glucose tolerance, glucose plus galactose tolerance and d-xylose excretion tests were comparable in the 2 groups as were measurements of intestinal villi and surface epithelial cell heights. Two of the patients with lactose deficiency had steatorrhea, but Its relationship to lactose intolerance is not known.