Changes in the prevalence of anemia in Korean adolescents, 1998–2018

BACKGROUND: Anemia is an important health problem affecting approximately 25% of the global population. Although its prevalence is decreasing worldwide, few studies have examined the prevalence of anemia in Korean adolescents. PURPOSE: This study aimed to determine the prevalence of anemia in Korean adolescents over the past 21 years using data from the Korea National Health and Nutrition Examination Survey. METHODS: We investigated the prevalence of anemia in adolescents aged 10–18 years for the period 1998–2018 according to sex, age, residential area, and household income. The effects of menarche age and menstruation were examined in female adolescents for the period 2001–2018. RESULTS: Among the total 11,782 participants, the weighted prevalence of anemia was 4.0%. The prevalence of anemia in male participants significantly decreased (from 3.0% to 0.5%, P<0.001), whereas that in female participants did not change significantly over time (from 7.9% to 8.5%, P=0.054). The average age at menarche was 12.4±0.0 years; the prevalence of anemia in females increased from age 13 years onward. Multivariate analysis revealed that anemia was more common in female than male participants (odds ratio [OR], 9.88; 95% confidence interval [CI], 7.19–13.57; P<0.001). In female adolescents, the prevalence of anemia increased with age (OR, 1.26; 95% CI, 1.15–1.38, P<0.001) and was 3.6 times higher after than before menarche (OR, 3.65; 95% CI, 2.21–6.05, P<0.001). CONCLUSION: Over the 21-year study period, the prevalence of anemia decreased among male adolescents but did not change in female adolescents. In female adolescents, age and menarche were identified as significant risk factors that require continued attention.