Hypoglycemia and cardiovascular disease

Hypoglycemia is always a barrier to control blood sugar in patients with diabetes. It makes physicians to have scruples in intensive glycemic control. Some large clinical trials have proven that intensive glycemic control could lower the rate of microvascular disease. Howevr, it is still controversial for macrovascular disease. Recent large clinical trials looking at intensive glycemic control have shown no benefit or potential harm in patients with a longer duration of diabetes. Thus, hypoglycemia as a risk factor for cardiovascular events is a topic of much dabate. Hypoglycemia causes sympathoadrenal activation, abnormal cardiac repolarization, increased thrombogenesis, inflammation, endothelial dysfunction, and impaired cardiac autonomic function. Despite hypoglycemia was not a likely explanation for the excess mortality in the ACCORD trial and no survival benefit in the ADVANCE trial, it was true both in standard glucose control and intensive glucose control that hypoglycemia was clearly associated with increased macrovascular, microvascular, and death from both cardiovascular and noncardiovascular causes. In conclusion, hypoglycemia is really a marker of vulnerability to a wide range of adverse clinical outcomes. But current evidences cannot make sure that hypoglycemia has a direct cause of these outcomes.