Study Links Decreased Hemoglobin Levels to Impaired Lung Function and Higher Risk of Airflow Obstruction in Men

"Additionally, men experienced a 17% reduced risk of airway obstruction. In women, while higher hemoglobin levels were linked to improved FVC, there was no significant effect on FEV1, FEV1/FVC, or the risk of AO," the researchers reported in BMC Pulmonary Medicine.

Chronic obstructive pulmonary disease (COPD) is a leading cause of mortality and morbidity worldwide, with common comorbidities including cardiovascular disease and depression. Anemia, a frequent COPD comorbidity, is linked to increased mortality and hospitalizations. Recent studies have also explored the relationship between hemoglobin levels and lung function, though findings remain inconclusive. Therefore, Youngmok Park, Institute for Innovation in Digital Healthcare, Yonsei University, Seoul, Republic of Korea, and colleagues aimed to assess the long-term relationship between hemoglobin levels and lung function in a community-based cohort in South Korea.

For this purpose, the researchers employed linear mixed regression analysis to examine the long-term associations between hemoglobin levels and lung function parameters, including forced vital capacity, forced expiratory volume in 1 second, and FEV1/FVC. Additionally, they used a generalized estimating equation to calculate the odds ratio (OR) for airflow obstruction based on Hb levels.

The study led to the following findings:

• Over an 8-year biennial follow-up of 4,468 individuals (median age, 53.9 years; 49.0% men), men showed a positive association between Hb levels and lung function (FVC: 16.7 mL, FEV1: 15.5 mL, FEV1/FVC: 0.18%) and a decreased incidence of AO (OR = 0.83).
• In women, Hb levels were positively associated with FVC (4.7 mL) but not with FEV1 (3.1 mL) or FEV1/FVC (0.01%). The incidence of AO was not significantly different (OR = 0.93).
• In postmenopausal women, higher Hb levels were linked to increased lung function (FVC: 11.8 mL; FEV1: 9.8 mL; FEV1/FVC: 0.09%), but the incidence of AO was not statistically significant (OR = 0.82).

"We explored the long-term relationship between Hb levels and lung function in the general Asian population. Higher Hb levels were linked to improved lung function, and in men, there was a reduced incidence of airway obstruction with rising Hb levels. Thus, a decrease in Hb levels may signal potential lung function impairments," the researchers concluded.

Reference:

Kim, J., Kim, Y.T., Leem, A.Y. et al. Longitudinal association between hemoglobin and lung function with insights into the incidence of airflow obstruction: an observational study. BMC Pulm Med 25, 50 (2025). https://doi.org/10.1186/s12890-025-03505-3