Abstract

Plasma counterregulatory hormones and symptoms were measured during hypoglycemia in the postprandial and in the fasting state in humans to establish differences in physiological responses. We studied 8 nondiabetic subjects and 10 subjects with type 1 diabetes on two different occasions during clamped insulin-induced hypoglycemia (2.4 mmol/l) in the sitting position. On one occasion, subjects ate a standard mixed meal, and on the other they remained fasting. In response to postprandial as compared with fasting hypoglycemia, nondiabetic subjects exhibited lower total symptom scores (6.6 ± 0.4 vs. 11.5 ± 0.8, P = 0.001), which was due to less hunger (1.1 ± 0.1 vs. 4.2 ± 0.2), lower suppression of plasma C-peptide (0.23 ± 0.1 vs. 0.08 ± 0.07 nmol/l, P = 0.032), and greater responses of plasma glucagon (248 ± 29 vs. 163 ± 25 ng · l⁻¹ · min⁻¹, P = 0.018), plasma adrenaline (4.5 ± 0.6 vs. 3.1 ± 0.4 nmol · l⁻¹ · min⁻¹, P = 0.037), norepinephrine (3.8 ± 0.3 vs. 3.2 ± 0.2 nmol · l⁻¹ · min⁻¹, P = 0.037), and pancreatic polypeptide (217 ± 12 vs. 159 ± 22 pmol · l⁻¹ · min⁻¹, P = 0.08). Except for plasma C-peptide, responses in diabetic subjects were similarly affected. Notably, in diabetic subjects responses of glucagon, which were absent in the fasting state, nearly normalized after a meal. In conclusion, in the postprandial compared with the fasting hypoglycemic state, total symptoms are less, but counterregulatory hormones are greater and responses of glucagon nearly normalize in type 1 diabetic subjects.