Higher omega-3 index is associated with more rapid heart rate recovery in healthy men and women

Abstract

BackgroundPrevious studies have suggested that omega-3 polyunsaturated fatty acids (n-3 PUFA) can favorably influence cardiac autonomic tone. However, data regarding n-3 PUFA status and heart rate recovery (HRR) in healthy adults are sparse. PurposeTo examine the association between n-3 PUFA status and HRR. MethodsParticipants included 13,912 patients who underwent a comprehensive examination at the Cooper Clinic, Dallas TX. Fitness was determined from a maximal exercise test. HRR was calculated by subtracting the heart rate at 1, 3, and 5 min of an active recovery period from the maximal heart rate. Participants were categorized as having a low (<4%), normal (4–8%) or optimal (>8%) Omega-3 Index (O3I) (i.e., erythrocyte levels of eicosapentaenoic and docosahexaenoic acids). Multiple linear regression was used to model the association between O3I and HRR adjusting for age, maximal METs, body mass index, and smoking by sex. ResultsHigher categories of O3I were associated with greater HRR at 1 min (men: 23.7, 23.9, 24.6 beats/min; women: 23.9, 24.6, 25.9 and 3 min (men: 52.4, 52.9, 53.6 beats/min; women: 51.9, 53.4, 54.6), p trend <0.01 for all. Corresponding HRR at 5 min were (men: 60.0, 60.2, 60.7 beats/min, p trend=0.09; women: 59.4, 60.8, 61.6, p trend <0.001). The HRR gradients across O3I categories were steeper in women than men at 1, 3, and 5 min (p<0.03 for all sex x O3I category interactions with HRR). ConclusionsA direct relationship between HRR and O3I values was observed in both men and women, with a steeper gradient in women. These findings suggest a potential cardioprotective mechanism for n-3 PUFA.