The influence of sex on the relationship between heart rate recovery and other cardiovascular risk factors in apparently healthy subjects

Heart rate recovery (HRR) is an important indicator of cardiovascular health. The purpose of the present investigation is to examine the influence of sex on the relationship between HRR and other markers of cardiovascular health. Two hundred and seventy-five apparently healthy subjects participated in this study. Subjects underwent cardiopulmonary exercise testing (outcome measures: VO(2max) and HRR 1 and 2 min into recovery), lipid analysis, measurement of resting systolic and diastolic blood pressure and measurement of aortic wave velocity (AWV in m/s) via magnetic resonance. HRR both at 1 min (HRR(1)) and at 2 min (HRR(2)) were higher in males. In general, the correlation between HRR(1) and other measures of interest was weaker than that found with HRR(2) in both male and female subjects. With respect to HRR(2), the relationship with other measures of interest was stronger in the female subgroup. Specific to arterial stiffness, the correlation between HRR(2) and AWV was -0.33 and -0.46 (P<0.001 for both) in male and female subgroups, respectively. The results of the present study indicate that both gender and the timing of HRR measurement influence its relationship with other important cardiovascular risk factors.