The Blood Pressure Response To Occupational Standing By Sex. A Pilot Study

The long-term health benefits and efficacy of standing desks are unknown. Previous work indicates that blood pressure and cardiovascular stain may be higher while standing. Sex may also influence these factors. PURPOSE: To evaluate the cardiovascular differences between sitting and standing in females vs. males. METHODS: A total of 33 individuals, 18 female (F; age: 24 ± 4 yrs, height: 1.65 ± 0.06 m, weight: 63.8 ± 11.0 kg) and 15 male (M; age: 23 ± 3 yrs, height: 1.82 ± 0.11 m, weight: 90.8 ± 22.4 kg), completed the study. Volunteers began in a seated resting no-work position (REST) followed by two 15-minute mouse driven mental task trials while either sitting (wSIT) or standing (wSTD). Trials were completed back-to-back in random order. Throughout the test, a continuous finger plethysmography blood pressure system monitored mean arterial pressure (MAP), cardiac output (Q), and total peripheral difference (TPR). Data from the last five minutes of each condition was averaged. Variables were calculated as change scores from REST. A 2x2 ANOVA was used to determine differences between sex (F vs. M) and condition (wSIT vs. wSTD). RESULTS: There were no differences in ∆MAP (wSit: F -0.05 10.4 mmHg, M wSIT -0.89 ± 7.71 mmHg; wSTD: F -0.74 ± 12.2 mmHg, M 2.44 ± 8.35 mmHg) between sex (p = 0.638) or condition (p = 0.646), with no interaction (p = 0.419). The ∆Q (wSIT: F 0.21 ± 0.4 L/min, M -0.06 ± 0.8 L/min; wSTD: F -0.31 ± 0.5 L/min, M 0.15 ± 0.9 L/min) was not different between sex (p = 0.703) or condition (p = 0.834), but did have a significant interaction (p = 0.039). A Tukey HSD post hoc analysis showed the ∆Q for F wSTD was significantly less than M wSTD and F wSIT (both p < 0.05). The ∆TPR (wSit: F -0.139 ± 0.29 PRU, M 0.011 ± 0.47 PRU; wSTD: F 0.171 ± 0.37 PRU, M -0.081 ± 0.37 PRU) was not different between sex (p = 0.652) or condition (p = 0.841), but had a significant interaction (p = 0.038). A Tukey HSD post hoc analysis showed the ∆TPR for F wSTD was significantly elevated compared to F wSIT (p < 0.05). CONCLUSION: MAP was unaffected by computer work and body position, but standing altered the physiological support for MAP between F and M. In the wSTD condition, F experienced a significant decrease in Q requiring a compensatory increase in TPR. Conversely, M in the wSTD condition experienced a maintenance of both Q and TPR to support MAP.