Introduction: Hypertension is one of the most important preventable risk factors for cardiovascular disease. This observational study aimed to depict the role of regular blood donation on the systolic and diastolic blood pressure (SBP and DBP, respectively) in hypertensive patients in comparison with normotensive people.
Methods: This study was performed as a cross-sectional descriptive study on 546 blood donors of Vesal Blood Donation Center in Tehran who donated between 1 and 4 times in the period of 2016-2017. Donors were divided into two groups (hypertension and normal blood pressure) based on the systolic blood pressure (SBP) and diastolic blood pressure (DBP) at the time of the first donation. The trend of changes in blood pressure after each donation (second, third and fourth donation) was assessed using SPSS ver. 16 and One way-Anova statistical test.
Results: In the group of hypertensive patients,, after four blood donations, systolic and diastolic blood pressure showed a statistically significant decrease after three or four donations.
Systolic blood pressure in this group after the fourth donation decreased from the mean of 149.1 to 141.6 mm Hg (P = 0.03) and diastolic blood pressure decreased from 90.04 to 86.08 mm Hg (P = 0.04 also), respectively. Decreased blood pressure was also observed in the normal group, although this significant decrease was not reported (P> 0.05).
Conclusion: Our results corroborated a down-regulatory effect of regular blood donation on BP in hypertensive people.  These findings are rather encouraging people toward voluntary blood donation and can be considered in therapy-related issues.