Hypoglycemia: Cause or marker of other health problems?

Severe hypoglycemia is strongly associated with increased risks for a range of adverse clinical outcomes, including macrovascular and microvascular events and death, according to a study involving more than 11,000 patients with type 2 diabetes mellitus. Whether hypoglycemia is a causal factor or merely a marker of vulnerability to such events remains a mystery.

Australian researchers followed study participants for a median of 5 years. During that time, 231 had at least 1 severe hypoglycemic event; of these, 150 had been assigned to the intensive glucose control cohort, and 81 were in the standard glucose control group. Median times from the onset of severe hypoglycemia to the first major macrovascular event, the first major microvascular event, and death were 1.56 years, 0.99 years, and 1.05 years, respectively.

Compared with those without severe hypoglycemia, patients with the condition were almost 3 times as likely to suffer a major macrovascular event (hazard ratio [HR], 2.88; 95% confidence interval [CI], 2.01-4.12), almost twice as likely to suffer a major microvascular event (HR, 1.81; 95% CI, 1.19-2.74), almost 3 times as likely to die from a cardiovascular cause (HR, 2.68; 95% CI, 1.72-4.19), and almost 3 times as likely to die from any cause (HR, 2.69; 95% CI, 1.97-3.67; P<.001 for all comparisons). The researchers found similar associations for nonvascular conditions, including respiratory, digestive, and skin ailments.