Somotype and blood pressure of rural south afric an girls aged 6 to 13 years: ellisras longitudinal growth and health study

Introduction

Physique has been useful in assessing the outcomes of underlying growth and maturity processes, which leads to a better understanding of variation in both children and adults physique and their health [1]. High endomorphy rating has been associated with high blood pressure in adults, which poses a serious threats to adult health status while this threats has received little attention in children [2]. The main objectives of this study were to determine the somatotype and blood pressure levels in 6-13 year old Ellisras rural girls, of South Africa. Additionally the association of somatotype and blood pressure were investigated.

Method

A total of 917 girls aged 6 to 13 years, who were part of the Ellisras Longitudinal Study [1] were studied. The anthropometric variables (stature, body mass, femure, humerus, arm flexed and tense, calf girth, triceps, subscapular, supraspinal and medial calf skinfold) and techniques selected were those described in Norton & Olds [3]. The Heath-Carter method of somatotyping were followed [3]. An average three diastolic and systolic blood pressure readings were taken with the child seated and rested for at least 25 minutes, with an electronic blood pressure monitoring kit. The bladder of the Micronta device contains an electronic infrasonic transducer that monitors the pulse rate and blood pressure and displays them concurrently on the screen. The device is a versatile instrument that has been designed for research and for clinical purposes. Descriptive statistics for the three-somatotype components were calculated in each age group. Frequencies and percentage frequencies for the somatotype categories were calculated. Somatotype ANOVAs between age groups were calculated using SADs between adjacent interval to examine any significant changes in three-dimensional distances between age groups somatotypes.

Results

Mean endomorphy ranged from 2.5 to 3.5, mesomorphys ranged from 2.0 to 4.6 and ectomorphy ranged from 3.9 to 5.2 between the age of 6 to 13 years. There is a gradual increase in the somatotype component across the age. The girls dominated in the mesomorphic ectomorph and mesomorph-ectomorph to balanced ectomorph category. The SAD exhibit an insignificant increase in somatotype between adjacent age groups and there is a significant increase in the older age groups as compared to the younger age groups. Mean systolic blood pressure range from 88.8 to 105.5 mmHg from the age of 6 to 13 years. Diastolic blood pressure ranged between the age of 63.5 to 69.9 mmHg across the age range. Both systolic and diastolic blood pressure exhibits a slight insignificant increase from one age group to the other. Endomorphy correlate (r=0.37) well with systolic blood pressure than any other somatotype components at older age group children.

Discussion and Conclusion

The fact that endomorphy components and systolic blood pressure correlate better than other somatotype components raises a serious concern in this sample. The need to managed hypertensive individual is evident in this sample so as to combat this chronic disease at an early age. Follow up studies should investigate the relationship between blood pressure and dietary electrolytes (sodium, potassium, calcium), dietary protein, lipids and fibers, alcohol and total energy consumption of these children.
Acknowledgement: The financial support received from Vrije University, Amsterdam, Netherlands and the University of the North, South Africa, National Research Foundation and Medical Research Council of South Africa for the Ellisras Longitudinal growth and Health study is thankfully acknowledged.

References

[1]. Monyeki KD, et al. (2002). Stability of somatotypes in 4 to 10 year-old rural South African girls. Annals of Human Biology 29(1): 37-49.
[2]. Pediatrics (1996). National High Blood pressure Education program working group on hypertension control in children and adolescence ,pediatrics, 98 (4): 649-658
[3]. Carter J.E.L., & Heath, B.H. (1990). Somatotyping-Developments and applications. Cambridge: Cambridge University press
[4]. Norton K & Olds T. (1996). Anthropometrica. Sydney: University of New South Wales Press: 120- 267.