Association of serum hemoglobin level with the risk of carotid plaque beyond metabolic abnormalities among asymptomatic adults without major adverse clinical events: a cross-sectional cohort study

BACKGROUND: The serum hemoglobin (Hb) level is closely related to adverse clinical outcomes. However, data on the association of Hb levels with subclinical atherosclerosis beyond metabolic abnormalities are limited. METHODS: This study evaluated the association among serum Hb level, metabolic syndrome (MetS), and the risk of carotid plaque formation in asymptomatic adults without a history of major adverse clinical events. RESULTS: A total of 2560 participants (mean age: 60 ± 8 years, 32.9% men) were stratified into four groups based on Hb quartiles, as follows: ≤ 12.8 g/dL (group I), 12.9–13.6 g/dL (group II), 13.7–14.5 g/dL (group III), and ≥ 14.6 g/dL (group IV). The overall prevalence of MetS and carotid plaque was 37.2% and 33.4%, respectively. The prevalence of MetS increased with increasing Hb level (group I: 27.4% vs. group II: 35.9% vs. group III: 42.6% vs. group IV: 44.1%, p < 0.001). The prevalence of carotid plaque was 34.3%, 28.1%, 32.8%, and 39.5% in groups I, II, III, and IV, respectively. Univariate logistic regression analysis showed that MetS was associated with an increased risk of carotid plaque (odds ratio [OR] 1.568, 95% confidence interval [CI] 1.326–1.856, p < 0.001). Only group II showed a lower risk of carotid plaque than group I (OR 0.750, 95% CI 0.596–0.943, p = 0.014). Multiple logistic regression models showed consistent results after adjusting for clinical factors, including MetS and its individual components. CONCLUSION: Serum Hb level is associated with the risk of carotid plaque beyond MetS and its components in a relatively healthy adult population.