Inter-arm systolic blood pressure dependence on hand dominance.

Inter-arm systolic blood pressure differences (SBP-DIFF) ≥ 10 mmHg have been reported useful to predict future cardiovascular-related morbidities. Although well studied in patients, there is little information on healthy young adults and the role of hand-dominance as a factor affecting SBP-DIFF. As dominant arms (DOM) tend to have greater girth and muscle development than nondominant arms (NDOM) it was reasoned that cuff pressures needed to obtain SBP may be greater on DOM causing DOM SBP to be greater. To test this hypothesis and also provide typical values, SBP was measured in left and right-handers (29·4 ± 10·4 years) in whom handedness was clearly defined. Handedness was determined by a multi-question form in 90 young adults (45 male) and SBP-DIFF determined via simultaneous measurements done in triplicate on seated subjects. The percentage of left-handers in male and female sub-groups were equal at 37·8%. Results show that the absolute SBP-DIFF in left-handers (mean ± SD) was 4·4 ± 3·8 mmHg and for right-handers was 5·0 ± 4·2 mmHg (P = 0·362). There was also no statistically significant difference among 1st, 2nd and 3rd measured SBP-DIFF for either right or left-handers or differences between right and left-handers. Results show no evidence of a higher SBP in DOM and thus clarifies the hand-dominance issue as a factor not generally needing to be considered in clinical assessments. A potentially useful secondary outcome was the finding that 14·8% of this group had at least one measured SBP-DIFF ≥ 10 mmHg a fact that may have future relevance.