Association of Body Mass Index, Body Fat and Hypertension among Postmenopausal Women

The association of systolic and diastolic blood pressure with body mass index, waist hip ratio, the sum of three trunk skinfolds, the sum of the six skinfolds, the ratio of the sum of the trunk to the sum of the extremity skinfolds and relative fat pattern index and the correlations between each of these were examined among 30 hypertensive and 30 normotensive post menopausal women of Udaipur city. Anthropometric measurements and indices like weight, height, WHR, abdominal obesity, body mass index were higher in hypertensive women. Adiposity measures had consistant relationship with blood pressure. The correlation coefficients of the adiposity measure and blood pressure are intercorrelated with a few exceptions in both groups. Menopausal transition is characterized by ovarian failure and its consequent decrease in female sex steroid production. Earlier studies suggest that an increase and redistribution of body fat during menopause predispose women to cardiovascular disease and metabolic syndrome. Post menopausal women seem to have less lean body mass (LBM) compared with pre menopausal women. Accordingly, a changing ovarian hormonal status may accelerate the loss of muscle mass and result in decreased muscle performance and functional capacity (Sipila, 2003). Women face various psychological as well as physiological changes in the menopausal stage. There is a tendency to put on weight after menopause which is a predisposing factor for several other chronic disease like C.V.D., hypertension, etc. Seventy percent women of age 45-54 years are over weight or obese. Before the age of 50, majority of women tend to increase their weight slowly, whereas after menopause there appears to be an accelerated increase in fat mass and a change in preferential fat storage to a central part of body that is abdominal location (Evans, 2002). Obesity is recognized as an independent risk factor for hypertension, lipid abnormalities and diabetes mellitus, which are known to be independent risk factors for C.V.D. (Zodpey et al., 1994; Greenberg and Ibrahim, Address for correspondence: Dr. (Mrs.) Renu Mogra, B-9, Raghukul Complex, Pathon ki Magri, Behind Subhash Nagar, Udaipur 313 001, Rajasthan, India 1995; Ganguly et al., 1997). Several prospective studies have shown that both overall and abdominal obesity are related to cardiovascular disease, weight gain increases the risk of developing hypertension independent of age and blood pressure (Lee, 1996). Cardiovascular disease is the leading cause of death in women who have past the age of menopause (Upkar et al., 2000). Chandha (2001) also reported that majority of women, less than 65 years of age die of cardiovascular disease. The body mass index (BMI) refers to the overall fatness where as waist to hip ratio (WHR) and conicity index (CI) refers to abdominal adiposity. Kawada (2002) reported that BMI has an influence on blood pressure and lipid profile and is a good predictor of hypertension and hyperlipidemia. In recent years, the conicity index (CI) has been identified as the most important risk factor for cardiovascular disease than the WHR because CI has several advantages over the WHR (Valdez et al., 1993). Sensitivity of waist circumference is an index of disease risk in post menopausal women (Pelt et al., 2001). The WHR showed significant positive association with systolic and diastolic blood pressures but not with lipid variables in one of the rural populations (Gupta and Majumder, 1994). The body fat distribution changes according to menopausal status, with central obesity more pronounced in post menopausal women (Garauet, 2002). In the present study an attempt have been 172 K. KAUR AND R. MOGRA made to examine the association of BMI and other adiposity measures with blood pressure. MATERIALS AND METHODS Sixty women (30 hypertensive and 30 normotensive) in the age group of 45-55 years, who were not suffering from chronic diseases, with complete absence of cycle from last one year and not undergone surgical removal of uterus were purposively selected for the present study. Blood pressure of all the women was measured using automatic blood pressure monitor at the time of sample selection. The subjects were categorized based on their blood pressure values suggested by JNC-IV, 1997. The anthropometric measurements such as height, weight, waist and abdominal circumference and six skinfold thickness (SFT) ie measurements at triceps, biceps, subscapular, supra-iliac, abdominal and calf were recorded. By using the above anthropometric measurements, seven adiposity measures were derived namely body mass index [BMI = weight (kg)/height (m)], four measures of body fat distribution ie., waist to hip ratio (WHR = waist circumference/hip girth), conicity index [CI = abdominal girth (cm)/0.109 ) W(kg)/Ht(m ], the sum of six skinfolds (SF 6 = abdominal + subscapular + suprailiac + calf + triceps + biceps). Two measures of fat patterning ie., the ratio of the sum of the trunk to the sum of the extremity skinfolds [TE ratio: TSF 3 / (calf+triceps+biceps)] and relative fat pattern [RFPI = subscapular/(subscapular+suprailiac)] was also calculated according to James et al., (1998). The waist to hip circumference ratio (NIN, 1998), TSF 3 , SF 6 , TE ratio and RFPI (Hasstedt et al., 1989) and the conicity index was calculated according to Valdez et al. (1993). Statistical Analysis: Pearson’s correlation coefficient was used to determine the association of body fat measurements, age and hypertension.