Long-Term Effects of Hatha Yoga on Heart Rate Variability In Healthy Practitioners: Potential Benefits For Cardiovascular Risk Reduction.

Hatha yoga is commonly practiced in Western countries and is claimed to reduce risk of cardiovascular disease. The purpose of this study was to evaluate and compare time-domain and frequency-domain metrics of heart rate variability (HRV) in Hatha yoga practitioners and healthy controls. This cross-sectional study, which was conducted at a regional university and community wellness center, included convenience sampling of 19 Hatha yoga practitioners and 8 healthy controls. Using a lead II ECG system, 10 minutes of electrocardiogram (ECG) recording was collected for each participant. Artifact-free, 5-minute signals were used to derive time-domain and frequency-domain measures of HRV. The mean duration of Hatha yoga practice among practitioners was 11.47 ± 8 years. Demographic and anthropometric characteristics did not differ significantly between groups. Compared with the control group, the yoga group had significantly greater mean high frequency (HF) power (859.2 ± 1342.1 vs 175.5 ± 121.1; P = .04) and mean HF normalized units (nu) (57.0 ± 16.6 vs 36.7 ± 13.4; P = .02) and a significantly lower low frequency (LF)/HF ratio (1.1 ± 0.5 vs 2.2 ± 1.1; P = .01). No significant intergroup differences were observed for LF power, LF nu, or any time-domain measures of HRV. These results lack generalizability due to small sample size and lack of blinded assessment of outcome measures. Hatha yoga practitioners showed parasympathetic predominance compared with healthy controls. Analyzing frequency-domain HRV metrics enables detecting changes in cardiac autonomic function earlier than by analysis of time-domain metrics. Parasympathetic predominance demonstrated in the yoga group suggests Hatha yoga practitioners may be at lower risk for stress-related comorbidities.

Maternal endotoxin exposure results in abnormal neuronal architecture in the newborn rabbit.

Maternal intrauterine inflammation/infection is a potential risk factor for the development of neurologic disorders such as cerebral palsy (CP) in preterm and term infants. CP is associated with white matter and grey matter injury. In the current study, we used a rabbit model of CP in which pregnant rabbits are administered intrauterine injections of the endotoxin lipopolysaccharide. We then investigated the extent of neuronal damage in the newborn kit brain. We observed an overall decrease in the number of MAP2-stained neurons and an increase in Fluoro-Jade C-stained cells in the anterior thalamus of 1-day-old rabbit brain. We also observed an overall decrease in the number of branching points and spine density in the retrosplenial cortex, a major output region of the anterior thalamus that is involved in cognition and memory. The loss of spines and dendritic atrophy in the retrosplenial cortex may be caused by loss of presynaptic input from the thalamus. Our study indicates that the cognitive impairments seen in patients with CP may be related to the degeneration of neurons and abnormal arborization of the thalamic and cortical neurons.