November 07, 2022
2 minutes of reading
Children who are physically fitter than their peers experience a reduced risk of allergic conjunctivitis, according to a study presented at the American Academy of Ophthalmology in 2022.
But poor air quality can moderate some of the benefits of going outside to play, Tsai-Chu Yeh, MD, from Taipei Veterans General Hospital and National Yang Chiao Tung University in Taipei City, Taiwan, and colleagues write in the study.
“The increasing prevalence of allergic diseases, especially among the pediatric population, is a serious global public health problem,” Yeh said in a press release.
“Although the symptoms of allergic conjunctivitis are often considered minor, it tends to have a chronic course with multiple recurring episodes and can negatively affect children’s school performance and quality of life,” Yeh continued.
According to the poster presented, the study included 1,271,730 children in Taiwan who were examined at age 10 between January 1, 2010 and December 31, 2018, and followed for at least 1 year. The researchers tracked the incidence of allergic conjunctivitis among these children through national registries.
Using results from the National Physical Fitness Test, the researchers also objectively measured the children’s aerobic capacity, muscle strength, cardiorespiratory endurance and flexibility.
The six-year cumulative incidence of allergic conjunctivitis included 0.64% for students in the first quartile for musculoskeletal strength—which indicates the best power—0.73% for students in the second quartile, 0.78% for those in the third quartile and 0.88% for the fourth quartile (P < .001), according to the poster.
In a multivariate analysis adjusted for age, BMI, comorbidities, socioeconomic, and environmental factors, greater musculoskeletal strength was associated with reduced risk (adjusted HR per 1-meter incremental standing broad jump = 0.69 ; 95% CI, 0.61-0.78), with similar associations observed for increases in aerobic capacity (adjusted HR per quartile = 0.89; 95% CI, 0.85-0.93) and cardiorespiratory endurance ( aHR per quartile = 0.92; 95% CI, 0.91-0.94), according to the study abstract.
These associations were consistent across all BMI groups, the researchers continued.
In addition, the researchers noted in their poster that increased risks of allergic conjunctivitis and associations with female gender (aHR = 1.05; 95% CI, 1-1.11) and worse air quality index (aHR = 1, 06; 95% CI, 1.06-1.07) in a modified Cox regression analysis.
Additional risk factors for allergic conjunctivitis include urbanization, history of asthma, history of allergic rhinitis, and prior antibiotic use (P < 0.001 for all). The researchers pointed out that overweight children and children with increased exposure to dirty air were also at increased risk.
These results support previous studies suggesting a link between allergic conjunctivitis and air pollution, as well as a link between allergic conjunctivitis and urbanization, the researchers continued.
Furthermore, the researchers wrote, these links between allergic conjunctivitis, physical fitness and environmental factors are of great public health importance and should be noted by policy makers.
- Yeh TC et al. The relationship between physical fitness and risk of allergic conjunctivitis in children and youth: a national cohort study. Presented at: American Academy of Ophthalmology 2022; Sept. 30-Oct. 3, 2022; Chicago.