Mixed Meal Tolerance Test and Reactive Hypoglycemia

Abstract

Twenty-six patients with symptoms suggestive of postprandial hypoglycemia were investigated by oral glucose tolerance test (OGTT). During the OGTT, symptomatic hypoglycemia occurred in 10 (38.5%). Nine of these 10 sugjects were given mixed meal tolerance tests (MMTT) and symptomatic hypoglycemia failed to occur in any case. During the OGTT the nadir glucose was significantly lower than that during MMTT (44.1 +/- 1.5 vs. 77.3 +/- 4.8 mg/dl +/- SEM, respectively; p less than 0.0005). Serum insulin during MMTT peaked significantly earlier than during OGTT (46.7 +/- 7.3 vs. 86.7 +/- 11.7 minutes (SEM, respectively; p less than 0.0125). The early secretion of insulin during MMTT may explain the lack of symptomatic hypoglycemia in these patients. We conclude that reactive hypoglycemia, when tested by a more natural stimulus (such as mixed meal) rather than by OGTT, is uncommon.

Evaluation of a standardized hyperglucidic breakfast test in postprandial reactive hypoglycaemia

“…Compared to OGTT our breakfast test is markedly more insulinogenic [14], consistent with other authors who have also reported higher insulin responses in breakfast tests compared to OGTT [29]. However, Buss et al [8] and Hogan et al [9] showed similar insulin responses between breakfast and OGTT, and Charles et al [4] a markedly lower response. In this study, we compared our hyperglucidic breakfast with a more classic mixed breakfast which has been designed to be similar to those of Charles et al [4] and Hogan et al [9].…”

“…Another question is why this breakfast detected a particular glycaemic pattern in patients with suspected PRH, while breakfasts administered by other authors [4,8,9] did not. Composition of the diverse breakfast tests employed in the literature markedly differs.…”

“…It contains 64 % carbohydrates, while those of Lefebvre and Luyckx [12], Hogan et al [9] and Charles et al [4], respectively, contain 47, 50 and 48.3 % carbohydrates. The paper of Buss et al [8] does not give the exact composition of the breakfast test. By contrast our breakfast test contains less protein than the breakfast test of previous authors (9 vs 15 % for Lefebvre and Luyckx [12] and Hogan et al [9] and 21.7 % for Charles et al [4]).…”

“…An equilibrated mixed meal was compared to the hyperglucidic breakfast. Its composition was calculated to correspond to the average of the three breakfast tests described in the literature which have not been shown to induce hypoglycaemia in patients referred for suspicion of PRH [5,8,9]. This breakfast comprised bread (40 g), two eggs, powdered skimmed milk (14.5 g, SACM, Hochfelden, France which is composed of 14 % fat, 31% protein and 43.2 % lactose), sugar (5 g) and rice krispies (25 g, comprising 86 % carbohydrates, 6 % proteins, and 1% lipids).…”

“…A possible alternative would be a standard mixed meal reproducing the normal nutritional habits of the subjects: if hypoglycaemia could be induced, it could be concluded that the subject may experience hypoglycaemia during their everyday life. Unfortunately, some trials with standard mixed meals have given unreliable results [5,8,9], leading to the conclusion that these patients do not experience hypoglycaemia after such a meal. Since PRH can be prevented with a diet correcting excessive carbohydrate intake [10], we hypothesized that the meals used in these studies were too equilibrated, and to some extent compensate for the abnormality responsible for hypoglycaemia; therefore the test was unable to detect the disease.…”