Based on our results, noise exposure is associated with pediatric headaches. Among the various precipitants of headaches, environmental noise affects children's health. [19] Based on previous environmental noise surveys, the World Health Organization (WHO) recommends not exceeding specific noise levels in children’s living areas.[20, 21] According to a study in Australia, noise is the most frequently endorsed precipitant in youth populations. [22] In report by the UAE, the second most common environmental exposure for school-aged children with migraines was loud noise.[23] A Swedish study showed that higher environmental noise was related to an increase in the prevalence of headaches in schoolchildren.[24] Thus, noise exposure is strongly related to headache provocation in pediatric populations.
We found that noise exposure associated with a longer duration of headaches in children. Environmental stimuli such as noise and light are related to increased sensitivity to migraine headaches.[25] Specifically, auditory stimuli induce cochlear disturbances, which affect the excitability of auditory neurons. It recruits the disruption of the normal inhibitory or facility of the higher neuronal center, including the brainstem. Thus, the mechanism of noise exposure could affect hearing threshold and loudness sensitivity. Moreover, sound stress-induced hyperalgesia is characterized by an abnormally heightened sensitivity to pain. Khasa et al. reported enhanced levels of immune mediators related to hyperalgesia induced by unpredictable sound stimuli and prolonged pain in a rat model of widespread chronic pain. [6, 26] Therefore, auditory stress might be related to sensitivity and prolongation of pain in neuro-provoked mechanisms in pediatric headaches.
The connection between noise and headache can occur through stress-related pathophysiological changes in the human body.[5] Most children are influenced by their daily behaviour and performance due to environmental stress. Noise exposure in children and adolescents is related to headaches and various psychosocial issues, including cognitive performance. In an Austrian survey, young children exposed to high-intensity noise showed increasing stressor indices such as systolic blood pressure, heart rate reactivity, cortisol level and decrements of mentality. [27, 28] In the cross-national study, noise exposure was associated with increased annoyance and impaired memory and reading comprehension in children.[29] In a cross-sectional study in Macedonia, school children exposed to the noise levels above the WHO guidelines showed decreased attention and social adaptability and increased opposing behavior. [30] Chronic non-auditory noise can also affect intellectual performance in children. [31] Prolonged headaches in children and adolescents can induce poor cognitive performance and decrease quality of daily life.[32] Therefore, environmental noise exposure should be considered a significant precipitant for managing pediatric health care.
This study has some limitations. First, we performed a retrospective study based on self-assessment. In subgrouping, we assessed the stages of puberty based on questionnaires completed by he participants themselves or by their parents without bone age and sex hormone levels. Second, we collected data from a small population over a relatively short period to evaluate exposure. Third, estimating noise exposure based on residential addresses and outdoor measurements, which assumes indoor noise levels, may have introduced bias. Although previous studies have shown a good correlation between indoor and outdoor noise levels [33, 34], limitations remain owing to the estimation of noise using Geographic Information System (GIS) spatial analysis for areas without noise information. Because noise measurement points are designated to represent noise levels considering factors such as population and area, our kriging method implemented for areas with a lower priority for measurement may not accurately reflect noise information. However, to our knowledge, this is the first study to reveal a correlation between environmental noise exposure and pediatric headache in South Korea.
In conclusion, we found that daytime and nighttime environmental noise exposure was significantly associated with headache duration. Further research is required to strengthen the evidence supporting these results.