Objective: To investigate the association between serum zinc levels and convulsive brain injury in infants with mild gastroenteritis complicated with benign infantile seizures (BICE) and febrile seizures (FC).
Methods: A case-control study method was conducted. 120 children with mild gastroenteritis and convulsion admitted to the First Affiliated Hospital of Hebei North University from January 2020 to January 2022 were enrolled as the research subjects. They were divided into BICE group and FC group according to the type of convulsion. The serum zinc level, the frequency and duration of convulsion, and the occurrence of convulsive brain injury in the two groups were recorded. Multivariate Logistic regression analysis was used to screen the risk factors for convulsive brain injury. The Spearman correlation method was used to analyze the association between serum zinc levels, clinical characteristics of convulsion and convulsive brain injury.
Results: A total of 120 children were enrolled, of which 81 developed to BICE and 39 developed to FC during hospitalization. The serum zinc level of children in the FC group was significantly lower than that in the BICE group (μmol/L: 39.24±6.50 vs. 48.65±7.21, P < 0.01). In the BICE group and FC group, the serum zinc level in children with more than 2 convulsions was significantly lower than that in the children with one convulsion (μmol/L: 37.65±6.50 vs. 53.17±7.55 in the BICE group, and 30.27±5.58 vs. 44.16±7.57 in the FC group, both P < 0.01). Serum zinc level in children with convulsion duration ≥ 5 minutes was significantly lower than that in the children with convulsion duration < 5 minutes (μmol/L: 38.75±6.74 vs. 51.21±7.58 in the BICE group, and 31.08±5.46 vs. 45.19±7.25 in the FC group, both P < 0.01). Moreover, the serum zinc level of children with different convulsion frequency and duration in the FC group was significantly lower than that in the BICE group (all P < 0.01). Among the 120 children, 9 cases of convulsive brain injury occurred, and the incidence rate was 7.50%. The incidence of convulsive brain injury in the BICE group was 1.23% (1/81), which was significantly lower than 20.51% in the FC group (8/39, P < 0.01). The serum zinc level of children with convulsive brain injury was significantly lower than that of children with non-brain injury (μmol/L: 28.50±5.00 vs. 60.22±7.31, P < 0.01), and the number of convulsion was significantly higher than that of non-cerebral injury (≥ 2 convulsions: 100.00% vs. 1.80%, P < 0.01), and the duration of convulsion in children with brain injury was significantly longer than that of non-brain-injured children (convulsion duration ≥ 5 minutes: 100.00% vs. 11.71%, P < 0.01). Multivariate Logistic regression analysis showed that decreased serum zinc level [odds ratio (OR) = 2.147, 95% confidence interval (95%CI) was 1.354-3.403], increased number of convulsion (OR = 3.452, 95%CI was 1.266-9.417), and prolonged convulsion duration (OR = 3.117, 95%CI was 1.326-7.327) were independent risk factor for convulsive brain injury in children with mild gastroenteritis and convulsion (all P < 0.05). Spearman correlation analysis showed that serum zinc level, convulsion ≥ 2 times, duration of convulsion ≥ 5 minutes and convulsion ≥ 2 times + convulsion duration ≥ 5 minutes were significantly negatively correlated with the occurrence of convulsive brain injury in FC children (r values were -0.546, -0.517, -0.522, and -0.528, all P < 0.01). There was no significant correlation between serum zinc level, convulsion ≥ 2 times, convulsion duration ≥ 5 minutes and convulsion ≥ 2 times+convulsion duration ≥ 5 minutes and convulsive brain injury in BICE children (r values were -0.281, -0.129, -0.201, -0.243, all P > 0.05).
Conclusions: Serum zinc level is related to the characteristics of convulsive symptoms in children with mild gastroenteritis complicated with FC, and has a strong negative correlation with the occurrence of convulsive brain injury. Active targeted intervention and treatment may help reduce the incidence of brain injury in children.