Evaluation of Pre-Treatment and Post-Treatment S100B, Oxidant and Antioxidant Capacity in Children with Diabetic Ketoacidosis

Serum Neuron-specific Enolase and S100 Calcium-binding Protein B in Pediatric Diabetic Ketoacidosis

Objective

Neuron-specific enolase (NSE) and S100 calcium-binding protein B (S100B) are markers of different neurological disorders. The aim was to investigate the relationship between NSE and S100B serum concentrations and the severity of diabetic ketoacidosis (DKA) in diabetic children.

Methods

Eighty children with DKA, 40 with type 1 diabetes mellitus (T1DM) without DKA and 40 healthy controls were enrolled. Severity of DKA was assessed according to blood pH and bicarbonate concentration. Serum NSE and S100B were measured in all participants. In the DKA group serum NSE and S100B were measured at three time points, at admission and at 12 hours and 24 hours after starting treatment.

Results

Children with DKA showed significantly higher serum levels of NSE at all time points compared to children with T1DM without DKA and controls (p<0.01), while serum S100B concentrations did not differ between the three cohorts. Children with T1DM but without DKA also had significantly higher serum levels of NSE (p<0.01) compared to healthy controls. Patients with low Glasgow Coma Scale score (GCSS) and those with moderate and severe DKA had significantly higher levels of NSE at all time points (p<0.01 for each) compared to patients with normal GCSS and those with mild DKA. No significant differences were found in serum S100B levels according to the severity of DKA and GCS (p>0.05). Younger age, lower GCSS, higher glucose and HbA1c, lower pH and lower serum bicarbonate were the risk factors associated with elevated NSE.

Conclusion

Serum NSE is elevated in all patients with type 1 DM and, in patients with DKA, correlates with severity of DKA. However, serum S100B concentration did not differ between T1DM with or without DKA and healthy controls.

Brain injury markers: S100 calcium-binding protein B, neuron-specific enolase and glial fibrillary acidic protein in children with diabetic ketoacidosis

BACKGROUND

To investigate serum levels of brain injury markers in diabetic ketoacidosis (DKA) and the relation of these markers with clinical and radiological findings of brain injury and laboratory results.

METHODS

Twenty-nine patients with DKA, 30 with type 1 diabetes mellitus (T1DM), and 35 healthy children were included. Clinical and laboratory findings, and the Glasgow Coma Scale (GCS) were recorded. In the DKA group, neuron-specific enolase (NSE), S100 calcium-binding protein B (S100B) and glial fibrillary acidic protein (GFAP) levels were measured at baseline and 6 and 12 hours after treatment. Magnetic resonance imaging was performed in the DKA group to demonstrate any brain injury.

RESULTS

No clinical or radiological findings of brain injury were found in any of the patients with DKA. In the DKA group, S100B was significantly higher than the healthy control and T1DM groups, while GFAP and NSE levels were not different from controls and T1DM patients. No significant differences were found in GFAP, NSE and S100B levels according to severity of DKA, diabetes duration and GCS.

CONCLUSION

NSE and GFAP levels do not increase in DKA patients without overt brain injury. Elevated levels of S100B, which is also synthesized from non-neuronal tissues, might arise from peripheral sources. A lack of concurrent increase in serum levels of these brain injury markers might result from the yet intact blood brain barrier or a true absence of neuronal damage. In order to reveal subclinical brain injury related to DKA, there is a need for studies concurrently assessing neurocognitive functions.

Deficiency of S100B confers resistance to experimental diabetes in mice

The calcium binding protein S100B has been implicated in diabetic neuronal and vascular complications but has not been examined in the development of diabetes. S100B knock out (S100B KO) and wild-type (WT) mice were injected with 40 mg/kg body weight streptozotocin (STZ) for 5 days. Blood and pancreatic tissue samples were obtained to examine islet structure and function, the profile of glucose and insulin and expression of glucose transporter 2 (Glut2), S100B and its receptor, the receptor for advanced glycation end products (RAGE). Primary islet β-cells cultures from WT mice were used to test the apoptotic potential of S100B. S100B KO mice were resistant to STZ induced-diabetes with lower urine volume, food and water intake compared to WT mice. S100B increased in the WT islet following diabetes but did not co-localize with beta or peri-islet Schwann cells but with CD3 + T lymphocytes. S100B KO mice exhibited enhanced glucose tolerance, insulin sensitivity, prevented β-cell destruction and functional impairment in response to STZ treatment. S100B deficiency was associated with decreased Glut2 and RAGE. In primary β-cell cultures from WT mice, S100B induced reactive oxygen species (ROS) and RAGE-dependent apoptosis. In the STZ diabetic animal model, abrogation of S100B enhances insulin sensitivity and reduces pancreatic islet, and β-cell destruction. S100B may be a promising target for pharmacological interventions aimed at repressing diabetes.