Haemoglobin glycation index and in-hospital mortality after acute myocardial infarction in patients with/without diabetes: A prospective, nationwide and multicentre registry

Aims: To assess the prognostic value of haemoglobin glycation index (HGI) for in-hospital mortality in acute myocardial infarction (AMI) patients with varied glucose metabolism status. Materials and Methods: A total of 5308 AMI patients were evaluated. HGI was calculated as the measured glycated haemoglobin A1c (HbA1c) minus the predicted HbA1c. The relationship between HbA1c and fasting plasma glucose (FPG) was assessed using linear regression analysis, which is presented as HbA1c = 0.272 × FPG(mmol/L) + 4.302. Predicted HbA1c for each participant was calculated by inserting corresponding FPG levels into this regression equation. The primary endpoint was in-hospital mortality. Results: Overall, 94 diabetic patients (4.5%) and 131 nondiabetic patients (4.1%) died during hospitalization. Restricted cubic splines analysis revealed an L-shaped association between HGI and in-hospital mortality in patients with type 2 diabetes mellitus (T2DM), whereas a strong trend toward a linear negative association was observed in patients without T2DM. In both diabetic and nondiabetic populations, patients with low HGI had a significantly higher risk of in-hospital mortality compared with those with moderate HGI, whereas no significant difference was found between high HGI and moderate HGI groups. In multivariable logistic regression analysis, patients in the low HGI group exhibited a 2.781-fold and 2.830-fold increased risk of in-hospital mortality compared to the moderate HGI group, among diabetic and nondiabetic populations, respectively. Conclusions: This study revealed an L-shaped association between HGI and in-hospital mortality in AMI patients with T2DM, with an inflection point of HGI at 0.69%. In contrast, a linear negative association was observed in AMI patients without T2DM.