Objective: The objective of the study was to investigate interarm differences of blood pressure (BP) and its determinants, and to clarify whether both arms are equally good in assessing BP and target organ damage in the general population.
Methods: We studied a representative sample of Finnish adult population with 484 study participants, ages 25–74 years. BP was measured twice by an oscillometric monitor simultaneously on both arms. Study participants underwent a clinical examination including measurements of serum lipids, glucose and indicators of target organ damage.
Results: BP was 2.3/0.2 mmHg higher on right than on left arm (P < 0.001/P = 0.15 for SBP/DBP differences). SBP and DBP measured on right and left arms correlated equally with left ventricular mass index (LVMI), interventricular septal thickness (IVST), posterior wall thickness (PWT), pulse wave velocity (PWV) and albuminuria. Higher SBP level was an independent determinant of both greater systolic and diastolic interarm BP difference. Exaggerated absolute diastolic interarm BP difference (>5 mmHg) was associated with higher BMI, arm circumference, LVMI, IVST and PWT, whereas exaggerated absolute systolic interarm BP difference (>10 mmHg) was not associated with any clinical variables.
Conclusion: There was only a small difference in BP between arms in a healthy general population. Both arms are equally good determinants of target organ damage. BP should be measured at least once on both arms and prefer the arm with higher BP readings in the future BP measurements.