Inter-arm Diastolic Blood Pressure Difference Induced By One Arm Exercise Or One Arm Ischemia: A New Approach To Assess Vascular Endothelia Function

Part one Aging Attenuates the Inter-Arm DiastolicBlood PressureDifference Induced by One Arm ExerciseObjectives: It is known that one arm exercise increases the inter-arm diastolic bloodpressure difference (dIAD) in young people, but no research was performed inmiddle-aged and more senior population. This study aimed to determine whetheraging impacts the exercise-induced dIAD in healthy subjects.Methods: Normotensive adults (n=120) were recruited and divided into the young(22.5±1.5y), middle-aged (42.8±4.6y) and senior (61.0±7.0y) groups. The right armexercise involved performing cycling movements at60times/min for three minutes.Bilateral brachial BPs were simultaneously measured with two automatic BPmeasurement devices before (baseline), immediately (0),5,10and15min after theexercise. The difference of bilateral diastolic BPs was calculated as BP l-r and itsabsolute value of equal or over10mmHg was recognized as IAD.Results: At baseline, the SBP l-r and DBP l-r were similar in three age groups. Onearm exercise induced markedly DBP decline in the exercised arm, and then increasedDBP l-r and dIAD prevalence in3age groups in an age-dependent manner. The dIADprevalence increased from baseline of zero to85%at0min in young,37%inmiddle-aged and30%in senior groups. One arm exercise did not significantly changeSBP l-r and systolic IAD prevalence in three groups. A reverse correlation was foundbetween the DBPl-r0and ages (r=-0.359, P<0.05), but no correlation between agingand SBPl-r0.Conclusion: Aging attenuates the levels and duration of inter-arm DBP differenceinduced by one arm exercise in healthy adults. Part two A control study of inter-arm diastolic blood pressuredifference induced by one arm ischemia and flow-mediated dilatationObjectives：To evaluate whether inter-arm diastolic blood pressure difference (DBPl-r)induced by right arm ischemia correlates with flow-mediated dilatation (FMD).Background：Because one arm exercise can induce DBPl-r, one arm ischemia in FMDtest may also induce DBPl-r.Methods：Bilateral arm BPs were simultaneously measured with two automaticdevices and right brachial artery diameter (D) was measured by ultrasound technique in108subjects (40healthy adults and68patients). Following baseline diameter (D0) andBP (BP0) taking, right brachial artery was occluded for5minutes. After occlusionrelease, diameter was measured at1,1.5and2min, and bilateral BPs were measured at3,4and5min. Their averages were recorded as post-D and post-BP, respectively. Thedifference between post-D and D0(D) was used for calculating D/D0. Thedifference of post-BPl-r and baseline BPl-r was calculated as BPl-r.Results：At baseline, bilateral SBPs and DBPs were similar. Right arm ischemiainduced significant DBP decline only in right arm (68.8±12.7vs72.6±12.0mmHg,P<0.05), which led to an increase of post-DBPl-r (3.97±3.61vs-0.03±2.51mmHg,P<0.05) and DBPl-r (4.00±3.75mmHg). A positive correlation was seen betweenD/D0and post-DBPl-r (r=0.625, p<0.001) or DBPl-r (r=0.744, p<0.001). BothDBPl-r and D/D0were negatively correlated with age.Conclusion：The inter-arm DBP difference induced by one arm ischemia may be apotential index for clinical evaluation of vascular endothelial function.