Interarm differences in systolic blood pressure and mortality among US army veterans: aetiological associations and risk prediction in the Vietnam experience study

Background Differences between the arms in systolic blood pressure (SBP) of 10mmHg have been associated with an increased risk of mortality in patients with hypertensive and chronic renal disease. For the first time, we examined these relationships in a non-clinical population. Design Cohort study. Methods Participants were 4419 men (mean age 38.37 years) from the Vietnam Experience Study. Bilateral SBP and diastolic BP (DBP), serum lipids, fasting glucose, erythrocyte sedimentation rate, metabolic syndrome, and ankle brachial index were assessed in 1986. Results Ten per cent of men had an interarm difference of 10 and 2.4% of 15mmHg. A 15-year follow-up period gave rise to 246 deaths (64 from cardiovascular disease, CVD). Interarm differences of 10mmHg were associated with an elevated risk of all-cause mortality (hazard ratio, HR, 1.49, 95% confidence interval, CI, 1.04-2.14) and CVD mortality (HR 1.93, 95% CI 1.01-3.69). After adjusting for SBP, DBP, lipids, fasting glucose, and erythrocyte sedimentation rate, associations between interarm differences of 10mmHg and all-cause mortality (HR 1.35, 95% CI 0.94-1.95) and CVD mortality (1.62, 95% CI 0.84-3.14) were significantly attenuated. Conclusions In this non-clinical cohort study, interarm differences in SBP were not associated with mortality after accounting for traditional CVD risk factors. Interarm differences might not be valuable as an additional risk factor for mortality in populations with a low risk of CVD.