Effects of brisk walking on blood pressure in the Chinese Han occupational population with a sedentary lifestyle: A baseline control trial

Background: Physical activity has proven to be effective in improving blood pressure (BP), but research on the beneficial exercise volume for BP control is limited. We assessed the intervention effects of walking on BP in the Chinese Han occupational population with a sedentary lifestyle to explore the appropriate exercise volume needed for BP control.Methods: A total of 802 subjects were recruited from enterprises and institutions for our study. This study was designed as an intervention study for a baseline control trial. All participants received a 3-month open and prescription pedometer-assisted self-monitoring walking intervention. Multiple linear regression models were used to assess the association between physical activity and changes in systolic (SBP) and diastolic (DBP) BP. We divided the effective step counts into five levels: 4000-<6000 (level 1), 6000-<8000 (level 2), 8000-<10000 (level 3), 10000-12000 (level 4), and >12000 (level 5) steps/day for statistical analysis to evaluate the exercise intervention efficiency.Results: Data of 688 participants who completed the study were analyzed. After 3 months, SBP and DBP decreased by 1.9 and 2.0 mmHg, respectively (P < 0.05). Taking level 5 (>12000 steps/day) as reference, SBP can be better controlled at levels 1-4: level 1 had the best effect (-6.05 mmHg, P=0.007), followed by level 2 (-3.54 mmHg, P=0.006), showing a significant dose-effect relationship between exercise and SBP. Furthermore, the effective step count of 6000-<8000 steps/day was better in controlling SBP in males (-4.26 mmHg, P = 0.014), while 4000-<6000 steps/day had a better effect on females (-6.86 mmHg, P = 0.037). The significant dose-effect relationship was only observed in the 36-50 age group. However, no significant dose-effect relationship between exercise and DBP.Conclusions: Brisk walking can effectively control BP in the Chinese Han occupational population with a sedentary lifestyle. There was a significant dose-effect relationship between exercise and SBP with differences in sex and age. Trial registration: ChiCTR-OOh-16010229. Registered 5 January 2017 - Retrospectively registered, http://www.chictr.org.cn/showprojen.aspx?proj=17362.