The reproducibility of power spectrum analysis of heart rate variability before and after a standardized meal.

We tested the reproducibility of the heart rate variability (HRV) measurements before and after a standardized meal. Heart rate recordings were obtained in 14 healthy subjects tested in a reclining position before and after a standardized meal on two separated occasions, apart by a 1-2-week interval. We measured three components of HRV: sympathetic activity (SYMP), parasympathetic activity (PSYMP) and the ratio of SYMP/PSYMP under controlled breathing and noncontrolled breathing conditions. We observed that all components were reproducible during noncontrolled breathing condition, whereas only PSYMP was reproducible during controlled breathing condition. Our results thus indicate that HRV measurements could be a useful, noninvasive and nonexpensive method to provide SYMP and SYMP/PSYMP in feeding behavior studies when measured under noncontrolled breathing conditions. Nonetheless, using a controlled breathing condition may be relevant when assessing the effect of various interventions or drugs on parasympathetic activity.