Ha Kyeong Won, MD
,
Division of Allergy and Clinical Immunology, Department of Internal Medicine, Seoul National University Hospital, Seoul, South Korea
Sung Do Moon, MD
,
Division of Allergy and Clinical Immunology, Department of Internal Medicine, Seoul National University Hospital, Seoul, South Korea
Kyoung Hee Sohn, MD
,
Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea
Hye-Ryun Kang, MD, PhD
,
Regional Pharmacovigilance Center, Seoul National University Hospital, Seoul, South Korea
Min-Koo Kang, MD
,
Division of Allergy and Clinical Immunology, Department of Internal Medicine, Seoul National University Hospital, Seoul, South Korea
Byung-Keun Kim, MD
,
Seoul National University Bundang Hospital, Seoul, South Korea
Ju-Young Kim, MD
,
Regional Pharmacovigilance Center, Seoul National University Hospital, Seoul, South Korea
So-Hee Lee, MD
,
Division of Allergy and Clinical Immunology, Department of Internal Medicine, Seoul National University Hospital, Seoul, South Korea
Woo-Jung Song, MD
,
Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea
Kyung-Mook Kim, MD
,
Department of Internal Medicine, Pogunhan Mom Hospital, Seoul, South Korea
Heung Woo Park, MD, PhD
,
Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea
Sun-Sin Kim, MD
,
Division of Allergy and Clinical Immunology, Department of Internal Medicine, Seoul National University Hospital, Seoul, South Korea
Ki-Woong Kim
,
Department of Psychiatry, Seoul National University Bundang Hospital, Seoul, South Korea
Hak Chul Jang, MD, PhD
,
Seoul National University Bundang Hospital, Seongnam, South Korea
Sang-Heon Cho, MD, PhD
,
Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, South Korea
Kyung-up Min, MD, PhD
,
Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, South Korea
Yoon-Seok Chang, MD, PhD
,
Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea
Background:Peripheral blood eosinophilia is a common clinical manifestation which draws medical attention. However there are little reports on blood eosinophilia in the elderly. We aimed to investigate the normal ranges of blood eosinophils and associated factors including allergic parameters, using the dataset of a community-based random elderly population in Korea.
Methods:A cross-sectional analysis was performed using the database of Korean Longitudinal Study on Health and Aging, a community-based elderly cohort. The primary outcome was peripheral blood eosinophil counts and the upper limit of the 95% confidence interval for absolute count of blood eosinophil counts was calculated for normal ranges. Demographic, socioeconomic, metabolic, comorbidities, allergic parameters, and lung function were analyzed. Atopy was defined with skin test by positive to any of 12 common inhalant allergens. Allergic history and symptoms were assessed by questionnaires.
Results: Cutoff value for blood eosinophilia was less than 406.6x103/mL (n=1,000). The prevalence of eosinophilia (>500x103/mL) and hypereosinophilia (>1,500x103/mL) were 4.12% and 0.20%, respectively. In univariate analyses, blood eosinophil counts was significantly related to male sex, and smoking status. However, in multivariate analyses, the association of blood eosinophil count with male sex appeared to be at least partly dependent on smoking status. Other potential determinants (P<0.10 in univariate analyses) were body mass index, atopy, current wheeze, and physician-diagnosed asthma. In multivariate linear regression analyses, the relationships between blood eosinophil counts and potential determinant factors were examined.
Conclusion: The normal range of peripheral blood eosinophils in the Korean elderly was ≤ 406.6 x103/mL (upper 95th percentile), which was almost identical to the reference range in the literature. Smoking was a major determinant factor for eosinophilia, and explained the association of eosinophilia with male sex. Other determinant factors were body mass index, atopy, and asthma. These findings could suggest a potential role of blood eosinophils as an epidemiologic marker for atopy and asthma in the elderly population.
