There is a strong well association between hypoglycaemia and cardiovascular events. Over the years, the definition hasn’t change but the classification is being re-evaluated from time to time. Older studies like the ACCORD showed in the past higher mortality rate in patients who experienced hypoglycaemia which we now define as severe. In the last few years there are many cardiovascular trials which provide us new information on the relationship between hypoglycaemia and cardiovascular events. In the LEADER trial we can see the proximity between hypoglycaemia event and the risk of MACE.
The lack of standardization regarding the definition and classification posing a problem while analysing the data and comparing the trials. The fact that hypoglycaemia in those trials is not captured by continuous glucose monitor devices, cause underestimation of the real magnitude of the problem and nocturnal hypoglycaemia is probably missed. While having those devices, the close relation might be seen more easily.
The consequences of hypoglycaemia are well described and among them we can find myocardial ischemia, arrythmia and cardiac failure. The endothelial dysfunction with more vasoconstriction and increased viscosity of the blood contributes to those events. Those changes can last for many hours after an hypoglycaemia event and can even persist up to a week after.