Postprandial Glucose
Blood glucose measured after eating, typically at 1-2 hours after a meal. GLP-1 receptor agonists are particularly effective at reducing postprandial glucose spikes through their combined effects of insulin stimulation, glucagon suppression, and delayed gastric emptying.
Technical Context
Postprandial glucose (PPG) is typically measured 1-2 hours after eating. Normal PPG: <140 mg/dL (7.8 mmol/L) at 2 hours. In type 2 diabetes, PPG elevations often precede fasting hyperglycaemia and contribute significantly to overall glycaemia (particularly when HbA1c is 7.0-8.0%). GLP-1 RAs are particularly effective at reducing PPG through three synergistic mechanisms: glucose-dependent insulin secretion (insulin release proportional to meal-induced glucose rise), glucagon suppression (preventing postprandial hepatic glucose output), and delayed gastric emptying (slowing nutrient absorption — this is the dominant short-term mechanism, reducing PPG peak by 30-50%). Short-acting GLP-1 RAs (exenatide BID, lixisenatide) have greater PPG-lowering effect relative to FPG-lowering than long-acting agents, because the gastric emptying delay is subject to tachyphylaxis with continuous GLP-1R exposure.