Assessment of Risk Factor for Cardiovascular Disease Using Heart Rate Variability in Postmenopausal Women: A Comparative Study between Urban and Rural Indian Women

Cardiovascular diseases are important causes of morbidity and mortality in postmenopausal women. A major determinant of cardiovascular health is the status of autonomic nervous system and assessment of Heart Rate Variability (HRV). Heart Rate Variability is a noninvasive and sensitive technique to evaluate cardiovascular autonomic control. Reduced HRV is an independent risk factor for the development of heart disease. This study evaluated the risk factors for cardiovascular diseases using HRV, between urban and rural Indian postmenopausal women ranging in age from 40 to 75 years. Findings of the analysis of HRV have showed that the total power which reflects overall modulation of cardiac autonomic activity ( ？ versus ), the absolute power of high frequency which is surrogate of cardiovagal activity ( ？ versus ), and low frequency that reflects cardiac sympathetic activity ( ？ versus ) were significantly higher in urban women than that of their rural counterparts. Further, among the anthropometric measures, waist circumference was significantly correlated with indices of HRV. The study concludes that rural Indian women are associated with an additional risk beyond that of ageing and postmenopausal status when compared to the urban women. The higher central obesity could be the contributing factor for developing higher risk for cardiovascular disease among the rural women. 1. Introduction As women age, their health is influenced by factors such as career, diet, physical activity level, the socioeconomic status, and environment [1]. These changes, together with natural menopause, process of ageing, and hormonal changes in the reproductive system, affect the well-being of women. The complex, interrelated nature of the process often makes it difficult to distinguish between the symptoms of ageing or those resulting from the loss of ovarian functions, and factors arising out of socioenvironmental conditions. The differences in socioeconomic, nutritional status and physical activity level between the urban and rural population might influence postmenopausal women health more significantly than the hormonal changes. Menopausal status is accompanied by unfavorable levels of cardiovascular risk factors, like changes in body fat, distribution from gynoid to android pattern, abnormal plasma lipids, increased sympathetic tone, endothelial dysfunction, vascular inflammation, and increased blood pressure [2]. A major determinant of cardiovascular health and prognosis is the status of autonomic nervous system [3], although ignored by many clinicians. Abnormal autonomic