Association Between Severe Hypoglycemia, Adverse Macrovascular Events, and Inflammation in the Edinburgh Type 2 Diabetes Study

Abstract

OBJECTIVE To determine whether a history of severe hypoglycemia was associated with an increased risk of subsequent macrovascular events in people with type 2 diabetes and to explore possible mediation of this association by inflammation. RESEARCH DESIGN AND METHODS A cohort of 1,066 adults aged 60–75 years with type 2 diabetes was evaluated prospectively. Baseline history of severe hypoglycemia and plasma levels of the inflammatory markers C-reactive protein, fibrinogen, interleukin-6, and tumor necrosis factor-α were recorded. Their association with incident macrovascular events after 4 years was explored. RESULTS At baseline, 87 participants (8.2%) reported one or more episodes of severe hypoglycemia within the preceding year, and at follow-up 99 participants (9.3%) had suffered a new macrovascular event. Hypoglycemia was associated with increased odds of macrovascular events (odds ratio [OR] 2.11 [95% CI 1.06, 4.21], P = 0.035), including coronary heart events (OR 2.44 [95% CI 1.13, 5.26], P = 0.023), largely due to increased myocardial infarction (OR 4.02 [95% CI 1.54, 10.48], P = 0.004). Hypoglycemia was also associated with increased levels of inflammatory markers, including a general inflammation factor derived using principal-components analysis (P = 0.030, after adjustment for cardiometabolic risk factors). However, the significant association between hypoglycemia and macrovascular events persisted after adjustment for inflammatory markers. CONCLUSIONS The odds of suffering a macrovascular event were higher in patients with type 2 diabetes who had a history of severe hypoglycemia. There was no evidence that a proinflammatory state had a major role in mediating this association.