Introduction: Sedentary behavior, specifically an acute bout of prolonged uninterrupted sitting, is associated with heightened cardiovascular disease (CVD) risk, with increased arterial stiffness (AS) being implicated as a principal pathophysiological mechanism. The current systematic review, with meta-analysis, aimed to consolidate the AS response to (1) prolonged uninterrupted sitting and (2) interrupted sitting, as assessed by central and peripheral pulse wave velocity (PWV).
Methods: In total, 326 articles were identified, of which 11 and seven met the inclusion criteria for objectives (1) and (2), respectively. Mean differences (MD) and 95% CI were calculated for all trials using a three-level random-effects model, with restricted maximum likelihood (REML) estimation. The amount of heterogeneity was estimated using Cochran's Q and Higgins's I2 tests.
Results: (1) Prolonged uninterrupted sitting resulted in a significant increase in carotid-femoral (cf) PWV (MD = 0.184 m/s, 95% CI = 0.098 to 0.270, p < 0.0003). (2) Interrupting bouts of prolonged sitting resulted in a significant increase in cf-PWV (MD = 0.127 m/s, 95% CI = 0.044 to 0.209, p < 0.0026) that was lower compared to the uninterrupted sitting.
Conclusion: An acute bout of uninterrupted sitting appears to increase cf-PWV; although interrupting prolonged sitting with brief physical activity is beneficial, it does not fully mitigate the response.
Keywords: arterial stiffness; prolonged sitting; pulse wave velocity.