Association of hypertension with body mass index in the rural elderly

Lee, Ka Young; Park, Min Seon; Park, Tae Jin

Abstract

BACKGROUND: This is a cross sectional study to assess the effect of BMI (body mass index) on blood pressure and to get the appropriate BMI range for the prevention and control of hypertension in old men and women.
METHODS
From 1996 to 1998 we obtained data for anthropometrics, blood pressure, serum blood profiles and health behaviors about 418 out of 668 old people having visited a charge free clinic in rural areas. First we tried to figure out the relationship between BMI and systolic or diastolic blood pressure in old men and women separately. After adjusting age, smoking, alcohol, blood glucose, total cholesterol, we checked the linear relationship between each quintile BMI group and prevalence of hypertension in old men and women and obtained prevalence odds ratio (POR) for hypertension in each the 2nd to the 5th quintile BMI group compared to the baseline hypertension prevalence of the 1st quintile BMI group.
RESULTS
Regardless of sex, there was significant correlations between BMI and systolic blood pressure (in men r=0.257, p=0.002;in women r=0,182 p=0.005) or diastolic blood pressure (in men r=0.204, p=0.014;in women r=0.256 p<0.001). The prevalence of hypertension in men and women increased 1.37 and 1.41 times respectively by each quintile BMI increase. According to each quintile BMI group in men (median BMI value of each quintile group;18.2, 20.4, 21.8, 23.3, 26.6 kg/m2), PORs for hypertension were 1.0, 3.7(95% C.I;1.05 12.68), 3.6(95% C.I;1.03 12.59), 6.5(95% C.I;1.89 22.29), 4.0 (95% C.I;1.11 14.36). In women, (median BMI value of each quintile group;18.6, 21.3, 22.9, 25.1, 28.3 kg/m2), PORs for hypertension were 1.0, 1.6(95% C.I;0.62 3.82), 2.9(95% C.I;1.22 6.99), 2.9(95% C.I;1.28 6.68), 4.2(95% C.I;1.73 9.98).
CONCLUSION
Regardless of sex, there was a significant positive association between BMI and prevalence of hypertension in the old and the risk of hypertension increased even in normal weight group compared to the underweight group. Further studies on the appropriate weight range to prevent and control hypertension in old people will be needed.