Blood Sugar Level Correlates with MI Prognosis in Diabetics
A recent study by fava et al was designed to prospectively investigate the prognostic value of admission blood glucose (BG) levels in diabetic and non-diabetic patients with acute MI. Three hundred thirty-three diabetic and 565 non-diabetic patients were studied over a 3.5-year period. The investigators noted a significant association between mortality and admission blood glucose in diabetic patients but not in non-diabetics. The authors conclude: ". . . a high blood glucose on admission is a bad prognostic indicator in a diabetic patient with an acute myocardial infarction. The excess mortality in diabetic patients with acute myocardial infarction can be attributed to the higher proportion with hyperglycemia." (Fava S, et al. The prognostic value of blood glucose in diabetic patients with acute myocardial infarction. Diabet Med 1996;13:80-83.)
A simple but elegant prognostic signnow, the cardinal question is . . . why? Since similar associations have been found between patient outcome and BG levels in stroke patients, I immediately wondered if elevated BG levels facilitate formation of toxic intermediates (e.g., free radicals, lipid peroxides), as they are hypothesized to do in stroke. An alternative explanation is that those diabetics with elevated BG levels had overall poorer glycemic control, and maybe even poorer health in general, in the pre-MI period. This explanation seems logical, in light of the fact that the authors relied on the admission BG level, rather than on in-hospital variations. Lots of food for thoughtno pun intended!