Beta-Cell Dysfunction and Insulin Resistance after Subarachnoid Haemorrhage

BACKGROUND: Hyperglycaemia is a common finding and an independent risk factor for increased morbidity and mortality in aneurysmal subarachnoid haemorrhage (SAH). Although in these patients hyperglycaemia is commonly ascribed to insulin resistance, there is little understanding of underlying mechanisms. AIMS: To prospectively study temporal disturbances of glucose metabolism after aneurysmal SAH in patients without known abnormalities of glucose metabolism and to explore possible correlations with markers of stress. METHODS: In consecutive aneurysmal SAH patients not subjected to insulin therapy, in-hospital and follow-up oral glucose tolerance tests (OGTTs) and assessments of insulin resistance, pancreatic β-cell function, free fatty acids (FFA) and cortisol were performed and compared with reference values. RESULTS: We included 13 patients. In the first 2 weeks of admission, median fasting glucose and FFA levels were elevated while insulin levels were not. OGTTs were indicative of glucose intolerance in all patients at days 3 and 7, while on follow-up 1 patient had glucose intolerance and all patients had normal fasting glucose levels. Pancreatic β-cell function was impaired throughout the first week and insulin resistance from day 4 to 10. Levels of cortisol correlated with higher fasting glucose and increased FFA. FFA in turn correlated with pancreatic β-cell dysfunction. CONCLUSIONS: Aneurysmal SAH patients have transient abnormalities of glucose metabolism. During the first week, it appears to result predominantly from transient pancreatic β-cell dysfunction, in combination with insulin resistance.