The present study assessed whether tefillin use (tight, nonocclusive, wrapping of the arm) elicits a remote ischemic preconditioning (RIPC)-like effect in subjects with both acute and chronic use. RIPC, created by short bursts of ischemia-reperfusion, has not been successfully taken to the bedside. Several large population studies have found that Orthodox Jewish men (who wear tefillin almost daily) have decreased cardiovascular mortality compared with non-Orthodox counterparts. We hypothesized that tefillin use is a relevant component in triggering a preconditioning effect. Jewish men ( n = 20) were enrolled; 9 men were daily tefillin users (conditioned) and 11 men were nonusers of tefillin as controls (naïve). Subjects were evaluated for adherence to traditional Jewish practice, had vital signs measured, blood drawn for analysis of circulating cytokines and monocyte function, and underwent brachial flow-mediated dilation to evaluate vascular reactivity at baseline (basal) and after 30 min of using tefillin (acute treatment). Under basal conditions, both groups had similar peak systolic velocity (SV), diameter, and flow volume, although the conditioned group had higher SV at 120 s postdeflation ( P = 0.05). Acute tefillin use augmented artery diameter and flow volume in both groups, with conditioned subjects experiencing higher SV than control subjects at 90 and 120 s postdeflation ( P = 0.03 and P = 0.02, respectively). Conditioned subjects had decreased inflammation, monocyte migration and adhesion, and endothelial activation compared with control subjects at baseline. Acute use of tefillin did not significantly alter monocyte function in either group. In this pilot study, acute tefillin use improves vascular function, whereas chronic tefillin use is associated with an anti-inflammatory RIPC-like phenotype. NEW & NOTEWORTHY We hypothesized that tefillin use among Orthodox Jewish men (who practice a nonocclusive leather banding of their nondominant arm) will induce a remote ischemic preconditioning phenotype. Chronic use of tefillin in Orthodox Jewish men was associated with increased systolic velocity and attenuated inflammation and monocyte chemotaxis and adhesion versus Jewish men who do not wear tefillin. Acute use of tefillin in both populations augmented brachial artery diameter and blood flow but not inflammatory profiles compared with baseline.
Keywords: chemokines; cytokines; flow-mediated dilatation; monocyte activity; remote ischemic preconditioning.