(P20-001-24) Hemoglobin Concentration Is Elevated in Adult Asthma Patients in the United States

Objectives: Asthma is one of the most common obstructive respiratory conditions, and its co-occurrence with iron deficiency anemia (IDA) can complicate the management of both conditions. The study evaluates the relationship between asthma status, iron deficiency, and anemia for women aged 20 years and above.

Methods: Data from National Health and Nutrition Examination Survey (NHANES) from 2005 to 2018 was used in this analysis. Subjects were classified as having asthma based on their affirmative responses to the following questions: 1) “has a doctor or other health professional ever told you that you have asthma?” and 2) “do you still have asthma?" Serum ferritin (SF) and soluble transferrin receptor (TfR) were measured by the Nutritional Biomarkers Branch at the National Center for Environmental Health. The hemoglobin concentration was measured at NHANES mobile examination center. Iron deficiency (ID), IDA, and anemia were determined using established cutoff values. We used linear and logistic regression models to assess the relationship between asthma and iron status, controlling for participants' characteristics. All statistical comparisons were evaluated at a 2-sided significance level of α= 0.05. 

Results: The analysis included a total of 5,001 women. The prevalence of asthma, ID, anemia, and IDA were 10.9%, 10.1%, 9.3%, and 5.5%, respectively. The prevalence of asthma was comparable between women aged 20-49 and 50-85 years (p= 0.302), but anemia was higher in the younger age group (9.2% vs 4.3%, p < 0.001). Women with asthma had comparable SF and TfR but slightly higher hemoglobin concentrations than those without asthma (13.5 g/dL vs 13.3 g/dL, p=0.025). Patients with asthma were found to have higher BMI (p < 0.001), hemoglobin A1C (p=0.001), systolic blood pressure (p=0.007), diastolic blood pressure (p=0.001), and lower HDL (p < 0.001). After adjusting for demographic and lifestyle variables, including age, race, education, health insurance, BMI, and family income to poverty ratio (PIR), asthma status was no longer associated of any iron status marker or anemia (all p</em>>0.05).

Conclusions: Patients with asthma had slightly higher hemoglobin concentration than those without asthma. However, this may be due to the patient's background and lifestyle characteristics.

Funding Sources: None