The Relationship Between Sitting Time and Arterial Stiffness in Obese African Americans

Abstract

Purpose: Sitting time and arterial stiffness have been associated with increased risk for cardiovascular disease (CVD) mortality. However, the association between objectively determined sitting time and arterial stiffness has not been previously evaluated. This relationship may be particularly relevant in African Americans who have greater CVD risk and arterial stiffness compared to Caucasians.

Methods: The analysis sample included 20 participants (46.4 + 7.3 years old; BMI: 36.9 + 6.1 kg/m2; 85% female). Sitting time was measured objectively for 7 days using 24-hour activPAL accelerometers (PAL Technologies Ltd., Glascow, UK). Sitting time during waking hours only was determined using a verified algorithm. Data collected also included amount of time spent sitting/lying for sleep and waking hours (defined as sedentary time) as well as standing time, stepping time, and steps/day. Arterial stiffness was assessed using carotid-femoral pulse wave velocity (cfPWV).

Results: No significant relationship was observed between cfPWV and sitting time (r= -0.05, p=0.85). Similarly, correlations between cfPWV and other activPAL variables (sedentary time [r= -0.07, p=0.77], standing time [r= 0.03, p=0.90]; stepping time [r= 0.10, p= 0.66]; steps [r= 0.11, p= 0.64]) were not significant. When adjusting for confounders of arterial stiffness, there was still no significant findings amongst cfPWV and all activPAL variables.

Conclusions: The results of the present study suggest that arterial stiffness is not associated with sitting time in obese African Americans. Future studies should include a larger sample size or larger variation in participant demographics.