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The effects of uninterrupted and interrupted sitting on blood pressure and arterial stiffness in patients with established coronary heart disease

Year: 2026

Type: article

Abstract: Sedentary behaviour is an independent risk factor for cardiovascular disease. In healthy adults, prolonged uninterrupted sitting acutely increases blood pressure (BP) and aortic stiffness; however, these effects can be mitigated with light physical activity interruptions. Whether such mitigation strategies are effective in at-risk populations remains unclear. This study examined the effects of uninterrupted and interrupted sitting on BP and arterial stiffness, measured by carotid-femoral pulse wave velocity (cfPWV), and femoral-ankle PWV in patients with established coronary heart disease (CHD). Using a randomised cross-over design, 14 CHD patients sat for 2 h uninterrupted (control [CON]), and 2 h interrupted with light physical activity (sit-to-stand, calf raises and walking) breaks every 30 min (ACT). Brachial BP and cfPWV were assessed immediately pre- and post-sitting. Time-by-condition effects were tested using linear mixed effects models with baseline adjustments. A significant time × condition interaction effect was detected for systolic BP (P = 0.037) with an increase in CON (mean difference [MD] = 15 mmHg [95% CI: 8, 23], P < 0.001) but not ACT (MD = 4 mmHg [95% CI: -4, 11], P = 0.334). A significant time effect was detected for cfPWV, with an increase across both CON and ACT conditions (MD = 0.76 m/s [95% CI: 0.52, 0.99], P < 0.001). For CHD patients, light activity breaks every 30 min can attenuate the impact of prolonged sitting on BP but not arterial stiffness; higher frequency or intensity of activity breaks may be required for better preservation of cardiovascular function.

Source: Experimental Physiology

DOI: 10.1113/ep093399