For people with diabetes who already have cardiovascular disease, a sharp postprandial blood glucose spike is like adding fuel to the fire. This is not an overstatement. Let’s look at the reasons:
Secondary damage to blood vesselsWhen blood glucose surges suddenly after a meal, the blood becomes more viscous. For patients with already narrowed blood vessels, this further clogs the circulation — similar to pouring honey into a rusty water pipe. Slower blood flow means the heart cannot receive enough blood and oxygen, which can easily lead to serious problems.
Blood pressure “roller coaster”Large fluctuations in blood glucose damage the delicate inner lining of blood vessels, causing blood pressure to swing wildly. For vessels already affected by atherosclerosis, this repeated stress is like beating an old, brittle rubber tube — the blood vessels may even rupture.
Overworked, exhausted heartA sudden postprandial glucose rise forces the heart to work overtime nonstop to maintain blood supply to all organs. If the patient already has coronary heart disease, the heart is already weakened. This extra burden can trigger atrial fibrillation, angina, and in severe cases, myocardial infarction.
Blood clots: a “time bomb”Postprandial hyperglycemia makes platelets in the blood overactive and prone to clumping together, greatly increasing the risk of thrombosis. If these clots break loose and travel, they can block a heart artery (causing a heart attack) or a brain artery (causing a stroke), which can be life‑threatening.