Cerebrospinal fluid electrolytes and acid-base in diabetic patients

Background - Diabetes mellitus (DM) has detrimental effects on the function of microvascular beds, resulting in blood-brain barrier (BBB) dysfunction. The objective of the study was to investigate whether DM affects the brain physiology through composition of cerebrospinal fluid (CSF) and compare gas tension and electrolyte levels in CSF between the diabetic and nondiabetic populations. Methods - Patients aged between 20 and 70 years scheduled for elective orthopedic or urologic surgery requiring spinal anesthesia were enrolled. They were assigned to either of the two groups (control or type 2 DM). Gas tension and electrolytes in the CSF and whole blood samples were measured in both groups. Results - All 49 enrolled patients (24 in the control and 25 in the DM group) completed the study. The concentrations of Na+ and Mg(2+ )in the blood were significantly lower in the DM group than those in the control. The levels of pCO(2) and HCO3- in the CSF were lower in the DM group than in the control group. In addition, there was a marked increase in the glucose level in both the blood and CSF in the DM group. Conclusion - The results show that there were some homeostatic changes in blood and CSF in patients with DM.