Chronic effects of gastroduodenal surgery on glucose and insulin response to oral glucose tolerance test in a population study.

Oral glucose tolerance test (OGTT) results were compared between 4,667 middle-aged males attending a preventive medical screening and intervention program in Malmö and the subjects in this sample who reported a history of previous operation for gastric or duodenal ulcer (n = 158, or 3.4%). 76% of the operated subjects were smokers in comparison with 50% in the general cohort of males of the same age. The glucose and insulin responses in the OGTT in both the smoking and non-smoking operated cases showed higher early peak values and a subsequent rapid drop of the levels with lower 120-min values of both glucose and insulin compared to the average screening cohort. This type of response to an oral glucose load had previously been well known in the acute and immediate postoperative stages of gastric and duodenal resection, but it had not been shown before that it seems to be a permanent effect and may chronically influence the results of OGTTs in the population. Gastro-duodenal surgery should be included among the factors which may significantly affect the chronic results and thereby also the clinical interpretation of the OGTTs in the population.