Blood pressure levels of Zambian rural adolescents and their relationship to age, sex, weight, height and three weight-for-height indices.

A study of blood pressure levels of 372 rural Zambian schoolchildren age 7-16 years showed that blood pressure increases with age. The association between age and blood pressure is decreased when growth is controlled for in the analysis. Girls tended to have either the same or slightly higher mean blood pressure levels at all ages than boys. The main determinants of blood pressure in the children were age, height and weight. Mean systolic blood pressure (SBP) values of the children were lower than those for Nigerian, American and worldwide adolescents of comparable age, whereas mean diastolic blood pressure values were similar to those of American and worldwide adolescents of comparable age. The associations between blood pressure and the three indices commonly used to measure relative obesity, i.e. weight-for-length, weight/height2 and weight/height,3 were only significant for weight-for-length after adjusting for height, suggesting that the other two indices may not be appropriate in studies focussed on children and should be applied with caution. The nonsignificant associations observed between blood pressure and the other two weight-for-height indices may be attributed to the almost nonexistence of obesity in this sample of children.