Abstract
Background - N-3 fatty acids may reduce the risk of sudden death by preventing life-threatening cardiac arrhythmias. Heart rate variability (HRV) and baroreflex sensitivity (BRS) reflect cardiac autonomic regulation; reduced values predict arrhythmic events and mortality. Effects of n-3 fatty acids on these risk indicators of arrhythmia have not been widely studied. We investigated the effect of supplemental intake of n-3 fatty acids on HRV and BRS in apparently healthy subjects aged 50 to 70 years.
Methods - After a run-in period of 4 weeks, 84 subjects were randomized to receive capsules with either 3.5 g of fish oil or placebo oil daily for 12 weeks. Before and after intervention, electrocardiograms and blood pressure were recorded for 10 minutes with standardized respiration of 15 breaths/min. The SD of the duration of all normal RR intervals (SDNN10) and the root mean square successive differences (RMSSD10) were calculated from the 10-minute recordings. We also computed low frequency power (LF) and high frequency power (HF). BRS was computed by integrating the spectral systolic blood pressure to interbeat-interval transfer function in the 0.05- to 0.15-Hz band.
Results - The different measures of HRV and BRS did not significantly improve with the intake of n-3 fatty acids. SDNN10 decreased by 3.05 ms or 7.7% (95% CI, -8.91-2.82 ms), and BRS decreased by 0.92 ms/mm Hg or 0.1% (95% CI, -2.66-0.81 ms/mm Hg) in the fish oil group compared with the placebo group.
Conclusions - N-3 fatty acids have no effect on HRV from short-term recordings and BRS in apparently healthy subjects.
Original language | English |
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Pages (from-to) | 344-344 |
Journal | American Heart Journal |
Volume | 146 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2003 |
Keywords
- acute myocardial-infarction
- serum cholesteryl esters
- signal-averaged electrocardiogram
- physical-activity scale
- sudden cardiac death
- fish consumption
- erythrocyte-membranes
- controlled trial
- cell-membranes
- dietary-intake