AGING AND GENDER EFFECTS ON RATE-PRESSURE PRODUCT: AN INDEX OF MYOCARDIAL OXYGEN CONSUMPTION

Abstract

Objectives: There are aging associated alterations in cardiac structure, metabolism, function. Evidence suggests alterations in myocardial metabolism contribute to the development, progression of heart failure. Hence it is essential to be aware of the impact of healthy aging on myocardial oxygen consumption. Rate-Pressure Product (RPP) is simple, non-invasive, easily measurable index of MVO₂. Seeking the effect of aging, we measured RPP, in apparently healthy men and women of different age groups. To know the influence of gender we compared the RPP in men and women in each age group. Methods : A total 152 healthy subjects (91 men, 61 women) were classified by age into four groups. Studies included recording of anthropometric parameters, physiological parameters, brachial systolic and diastolic blood pressure and ECG. Rate-Pressure Product was calculated. Results: Subjects of both genders showed an age related (18-65 years) decline of resting heart rate. Healthy men showed a gradual decline of rate pressure product from 18-65 years. Healthy young women between 20-35 years showed higher rate pressure product compared to men. Below 20 years RPP was lower in women compared to men. Between 35-54 years the gender differences in RPP diminished. Beyond 55 years RPP was higher in women compared to men. Conclusion : Varying influence of aging on myocardial oxygen consumption observed in men and women. Healthy aging is associated with decline in myocardial oxygen consumption in men. In women no significant variation observed. In each age group gender differences in myocardial oxygen consumption observed.