Fasting glucose and HbA_1c levels as risk factors for the presence of intracranial atherosclerotic stenosis

Background: Intracranial atherosclerotic stenosis (ICAS) is the most common cause of stroke, but the relationship of ICAS with fasting blood glucose (FBG) and glycated hemoglobin A1c (HbA_1c) is unclear. This study aimed to investigate the effects of increased FBG and HbA_1c concentration on ICAS.

Methods: A total of 4,012 patients aged over 40 years who underwent cerebral magnetic resonance angiography (MRA) were enrolled in this study, including 1,434 non-stroke controls and 2,578 patients with ischemic stroke. Participants were classified into four groups according to stroke and ICAS status. ICAS was defined as the presence of ≥50% stenosis in any intracranial artery. Multivariate regression analysis was used to evaluate the associations of FBG and HbA_1c with ICAS.

Results: Levels of fasting glucose and HbA_1c in patients with ICAS were significantly higher than those in patients without ICAS among both stroke and non-stroke groups. Multivariate regression analysis showed that elevated levels of fasting glucose (OR 1.14, 95% CI, 1.11-1.18, P<0.001) and HbA_1c (OR 1.22, 95% CI, 1.16-1.28, P<0.001) were independent risk factors for ICAS. In addition, patients with the DM (FBG ≥7.0 mmol/L) were at the high risk of ICAS in both non-stroke (OR 2.90, 95% CI, 2.11-3.99, P<0.001) and stroke (OR 1.99, 95% CI, 1.67-2.39, P<0.001) groups. Besides, subjects with the high risk of ICAS were found in the fourth HbA_1c quartile in both non-stroke (OR 3.50, 95% CI, 2.23-5.61, P<0.001) and stroke (OR 1.98, 95% CI, 1.50-2.63, P<0.001) groups.

Conclusions: The results suggest that elevated fasting glucose and HbA_1c levels are associated with high risk for ICAS.