Heart Rate Variability in Elderly Linked with Physical Activity
Correlations seen for greater total leisure-time activity, walking distance, walking pace.
For older adults, total leisure time physical activity (PA) as well as walking are prospectively associated with indices of heart rate variability (HRV), according to a study published online in Circulation.
Luisa Soares-Miranda, Ph.D., from the Harvard School of Public Health in Boston, and colleagues examined how PA prospectively relates to HRV among older adults. Serial longitudinal measures of PA and 24-hour Holter HRV were assessed over five years in 985 older U.S. adults.
The researchers found that greater total leisure-time activity, walking distance, and walking pace were prospectively associated with specific favorable HRV indices, after multivariable adjustment. These indices included higher 24-hour standard-deviation-of-all-normal-to-normal-intervals (P trend = 0.009, 0.02, and 0.06, respectively) and ultra-low-frequency-power (P trend = 0.02, 0.008, and 0.16, respectively).
Correlations were also seen for greater walking pace and markers of less erratic sinus patterns, including higher short-term-fractal-scaling-exponent (P trend = 0.003) and lower Poincare ratio (P trend = 0.02).
"Greater total leisure-time activity, as well as walking alone, were prospectively associated with more favorable and specific indices of autonomic function in older adults, including several suggestive of more normal circadian fluctuations and less erratic sinoatrial firing," the authors write. "Our results suggest potential mechanisms that might contribute to lower cardiovascular mortality with habitual PA later in life."