Group- and Sex-specific Effects of Age, Body Composition and Pulse Rate on Blood Pressure Variability in Some Cross-cultural Populations of Visakhapatnam District; South India

Background: Hypertension is becoming a major public health problem in developing countries. Blood pressure tends to vary cross-culturally and is influenced by various factors including age, body composition and pulse rate. This paper reports the influence of age, body composition and pulse rate on blood pressure variability.

Design: The data were collected from 1316 individuals (646 men and 670 women) belonging to two tribes (Khondh and Valmiki) inhabiting hilly tribal area and two castes (Wadabalija and Settibalija) from both rural and urban areas from Visakhapatnam district, Andhra Pradesh, India.

Results: There are considerable ethnic differences in blood pressure and body composition variables. Age contributes significantly to the variance in blood pressure in these populations. However the influence of age is less pronounced in Khondh, a primitive/unacculturized tribe, while age exerts a profound effect on blood pressure variability in Valmiki, an acculturizing tribe. Further, the effect of age is more pronounced on systolic than on diastolic pressure and it contributes more to the blood pressure of women than men. The subcutaneous fatness measures (sum of three trunk skin fold thicknesses and sum of three extremities skin fold thicknesses) are significant predictors of both systolic and diastolic blood pressure in Khondh, Valmiki and Wadabalija, while body mass index (BMI) is an important predictor of both systolic and diastolic blood pressure in Settibalija. Pulse rate is often found to influence blood pressure of women.

Conclusion: The age-associated variability of blood pressure confirms the proposition that variability is high in adverse environment, when modernization/acculturization is taken to represent environmental adversity. Apart from the influence of age, body composition/adiposity contributes significantly to the blood pressure variability.