Sonographic Evaluation of Carotid Intima-Media Thickness and Iron Status of Regular and First-Time Blood Donors in a Tertiary Hospital in South-West Nigeria

Background: Regular blood donation which decreases blood iron levels may protect against cardiovascular diseases (CVD). This protection against atherosclerosis can be assessed by Carotid Intima-Media Thickness (CIMT) a biomarker for atherosclerosis. This study sought to determine and compare the mean and maximum CIMT, the serum level of iron and plaque prevalence among regular and first-time blood donors in Lagos University Teaching Hospital (LUTH), Lagos.

Methods: A comparative, cross-sectional study involving 214 randomly-selected blood donors (107 regular and first-time blood donors each). Using a structured proforma, sociodemographic, anthropometric, radiological and laboratory data were collected from blood donors in the two groups. high frequency linear probe was used to assess CIMT, and presence of plaque in both extra-cranial carotid arteries. CIMT was the distance between the intima–blood interface and the adventitia–media junction and iron study included serum total iron, ferritin, transferrin and total iron binding capacity. Comparison between the study groups was done by Chi-square test and Student t-test/Mann-Whitney U-test for categorical and continuous variables respectively. Level of significance was set at p<0.05.

Results: The mean and maximum CIMT of both carotid arteries in regular blood donors (mean right CIMT-0.49+/-0.11mm, maximum right CIMT-0.58+/-0.14mm, mean left CIMT-0.51+/-0.16mm, maximum left CIMT-0.60+/-0.27mm) were significantly(p<0.05) lower than those of the first-time blood donors(Mean right CIMT-0.79+/-0.17mm, maximum right CIMT-0.93+/-0.25mm, mean left CIMT-0.83+/-0.31mm, maximum left CIMT-0.96+/-0.27mm). Median serum iron(10.5µmol/L; IQR:8.8-13.5µmol/L), ferritin(30.50µg/ml; IQR:16.2-600µg/ml) and transferrin(2.1g/L;IQR:0.9-2.3g/L) in regular blood donors were significantly lower(p<0.05) than serum iron (16.1µmol/L; IQR:13.7-18.6µmol/L), ferritin(158.0µg/ml; IQR:115-365.2µg/ml) and transferrin(2.3g/L; IQR:2.1-2.4g/L) in first-time donors. Plaque prevalence was significantly higher (ꭓ2=5.81; p – 0.016) in first-time (11.2%) than regular (2.8%) donors.

Conclusion: Regular blood donation significantly lower CIMT values, and iron parameters. Regular blood donation may offer protection against atherosclerosis.