A study of autonomic functions and obesity in postmenopausal women

BACKGROUND: Easy accessibility to Medicare and better living conditions has increased life expectancy in recent years. There are over 60 million postmenopausal women above 55 years in India. Obesity, physical inactivity, and altered estrogen metabolism play an integrated role in contributing to the disease risk profile of postmenopausal women. These same risk factors also affect modulation of the autonomic nervous system. A study was undertaken to test the hypothesis whether there is indeed an alteration in autonomic functions in obese postmenopausal women. MATERIALS AND METHODS: 60 postmenopausal women without any gross systemic disease whose body mass index and waist/hip ratio were recorded. Subjects were divided into two groups of 36 Non-Obese and 24 Obese. The two groups were well matched for age and menopausal duration. The physical as well as physiological parameters like valsalva ratio, heart rate variation with deep breath test, heart rate response to postural change (30:15 R-R interval ratio), orthostatic tolerance test, and isometric handgrip test were recorded. RESULTS: Results of valsalva ratio, deep breath test, and 30:15 R-R interval ratios and isometric handgrip test were significantly decreased and orthostatic tolerance values were significantly increased in Obese subjects. CONCLUSION: Findings show decreased sympathovagal activity with obesity in postmenopausal women.