An evaluation of oxidative and nitrosative stress in children-who-stutter and its relationship to severity

Although there has been much research into the cause of stuttering, it has not yet been fully clarified. There is known to be a close relationship between stress severity and stuttering. The aim of this study was to evaluate the levels of oxidative and nitrosative stress by comparing a stuttering group and a control group. It was also aimed to evaluate the relationship between the oxidative and nitrosative stress levels and the severity of the stutter.

The study included a total of 80 individuals, comprising a study group of 40 and a control group of 40. The severity of the stutter in the patient group was evaluated with the Stuttering Severity Instrument 3 (SSI). Blood samples were taken from both the patient and control groups and malondialdehyde (MDA), 3 nitrotyrosine (3-NT), nitric oxide (NO), catalase (CAT), and superoxide dismutase (SOD) concentrations were examined.

In the stuttering patients, MDA, 3-NT, NO, CAT, and SOD activity were determined to be statistically significantly higher than those of the control group (all p:0.001). In the ROC analysis, there was good diagnostic value for NO, with the area under the curve as 1.0. A direct, positive, statistically significant correlation was determined between SSI points and MDA values (r = 0.317, p = 0.046).

The results of the study showed that the oxidative and nitrosative stress levels of the stuttering patients were higher than those of the control group. With 100% sensitivity and specificity, it is thought that NO in particular could be important for the diagnosis and treatment of these patients. As the severity of the stutter increased, so there was an increase in MDA, suggesting that MDA is important in stuttering.