Association of Higher Hemoglobin Level With Significant Carotid Artery Plaque in the General Population

Objective: Serum hemoglobin (Hb) level affects the viscosity of blood. Several studies have reported that Hb level is associated with adverse cardiovascular outcome. However, there is a paucity of evidence on the association between serum Hb level and the risk of subclinical atherosclerosis. Thus, the objective of this study was to investigate the relationship between Hb level and risk of carotid plaque in a health checkup cohort.

Methods: This retrospective study analyzed a total of 3,805 individuals without history of cardiovascular disease (CVD) who underwent carotid ultrasonography (USG) between January 2016 and June 2018. Participants were divided into 4 groups based on Hb quartiles in each of male and female. Carotid plaque score was calculated based on USG reports. Multivariable logistic regression analysis was performed for each index of quartile groups regarding the risk of carotid plaque.

Results: Of 3,805 individuals (mean age, 52.62±10.25 years; 2,674 [70.28%] males), mean Hb level was 15.11±0.75 g/dL in male and 13.35±0.74 g/dL in female. When the Q1 group was compared to the Q4, increasing quartile of Hb was associated with the presence of significant carotid plaque (plaque score ≥3) in male (adjusted odds ratio [OR], 1.538; 95% confidence interval [CI], 1.182-2.001; p=0.001) and female (adjusted OR, 1.749; 95% CI, 1.058-2.676; p=0.01).

Conclusion: A high Hb level is associated with an increased risk of carotid plaques in individuals without history of CVD. This finding may support the need for early screening of CVD in individuals with high Hb levels.