The Second-Meal Phenomenon in Type 2 Diabetes

OBJECTIVE

In health, the rise in glucose after lunch is less if breakfast is eaten. We evaluated the second-meal effect in type 2 diabetes.

RESEARCH DESIGN AND METHODS

Metabolic changes after lunch in eight obese type 2 diabetic subjects were compared on 3 days: breakfast eaten, no breakfast, and no breakfast but intravenous arginine 1 h before lunch.

RESULTS

Despite comparable insulin levels, the rise in plasma glucose after lunch was considerably less if breakfast had been eaten (0.68 ± 1.49 vs. 12.32 ± 1.73 vs. 7.88 ± 1.03 mmol · h⁻¹ · l⁻¹; P < 0.0001). Arginine administration almost halved the lunch rise in plasma glucose (12.32 ± 1.73 vs. 7.88 ± 1.03 mmol · h⁻¹ · l⁻¹). The plasma free fatty acid concentration at lunchtime directly related to plasma glucose rise after lunch (r = 0.67, P = 0.0005).

CONCLUSIONS

The second-meal effect is preserved in type 2 diabetes. Premeal administration of a nonglucose insulin secretagogue results in halving the postprandial glucose rise and has therapeutic potential.The effect of a prior meal in decreasing the rise in blood glucose after a subsequent meal was first recognized almost a century ago (1). It has repeatedly been confirmed in healthy subjects, but tests with intravenous or oral glucose suggested that the second-meal effect does not occur in type 2 diabetes (2–4). We observed incidentally that a second meal in subjects with type 2 diabetes brought about a 70% lesser rise in blood glucose (5).This study was designed to determine whether the second-meal phenomenon is present in type 2 diabetes and, if so, whether this can artificially be induced as a possible therapeutic approach.