Sedentary Behavior, Physical Activity, And Baroreflex Sensitivity In Middle-aged And Older Adults

Abstract

Cardiovagal baroreflex sensitivity (BRS), a risk factors for cardiovascular disease, declines with advancing age. Previous studies reported that the higher amount of moderate- to vigorous-intensity physical activity is associated with the better BRS. However, the associations of BRS with sedentary behavior (SB) and light-intensity physical activity (LPA), which occupies most of the waking time, are not fully understood. PURPOSE: The purpose of this study was to examine the associations of BRS with SB and LPA in the middle-aged and older adults. METHODS: A total of 162individuals(64 ±9 years) participated in this study. Spontaneous BRS was evaluated by transfer function analysis of a 5-minute continuous data (blood pressure and cardiac period) in the supine position. The SB and LPA time were assessed using triaxial accelerometers. The oxygen consumption at ventilation threshold (VO2VT) was measured as the cardiorespiratory fitness parameter. RESULTS: A series of multiple linear regression analysis revealed that SB and LPA time were significantly associated with BRS after adjusting for potential covariates such as age, sex, body mass index, heart rate, systolic blood pressure, smoking, menopausal, and medication status (β= - 0.205, P= 0.018; β= 0.208, P= 0.018). These associations remained significant after adjusting for the VO2VT(β= - 0.189, P= 0.030, β= 0.200, P= 0.022). CONCLUSIONS: This cross-sectional study found that the time spent in SB and LPA are independently associated with BRS and suggests that lower SB and higher LPA contribute to maintaining BRS in middle-aged and older adults.