In both health and patients with diabetes, acute hypoglycaemia triggers counter-regulatory responses accelerating gastric emptying and increasing cardiac contractility. However, antecedent hypoglycaemia attenuates endogenous catecholamine and vagal responses to subsequent hypoglycaemia (1). Our objective was to determine the effect of antecedent hypoglycaemia on gastric and cardiac responses to subsequent hypoglycaemia in health.
Ten healthy males were studied on two occasions, each lasting 30 hours, separated by ≥ 6 weeks and randomised to either:
Gastric emptying (GE) was measured on day 1 and 2, for both control (GEC1, GEC2) and antecedent hypoglycaemia (GEAH1, GEAH2) periods, using scintigraphy. Cardiac contractility was measured using fractional shortening (FS) via 2D echocardiography on days 1 and 2 of the control (FSC1, FSC2) and antecedent hypoglycaemia (FSAH1, FSAH2) periods. Data are mean (SE).
Gastric emptying was faster (GEC2 AUC vs. GEC1 AUC, P=0.01) and fractional shortening greater (FSC2 vs. FSC1, P<0.01) during acute (single episode) hypoglycaemia compared to euglycaemia. Following antecedent hypoglycaemia, gastric emptying was unaffected (GEAH2AUC vs. GEC2 AUC, P=0.74, Figure 1) however fractional shortening may be reduced (FSAH2 vs. FSC2, P=0.06), although this was not statistically significant.
In health, the acceleration of gastric emptying during acute hypoglycaemia does not appear to be affected by antecedent hypoglycaemia whereas the increase in cardiac contractility may be attenuated.