Background
The prevalence of hypertension, an important risk factor for cardiovascular disease (CVD), is increasing in the developing countries and this may be connected with the economic transition in those countries. Adult hypertension is thought to be related to childhood and adolescent increases in blood pressure, and hence the need to monitor patterns in early life. This study investigates the BP patterns, and their correlates, of adolescents from different geographic areas of residence in Nigeria.

Methods
A total of 1,088 Nigerian adolescents from different geographic areas of residence were recruited for the study. Their blood pressures and anthropometric indices were measured using standard procedures. The association of blood pressure with height, weight, body mass index (BMI) and geographic area of residence was assessed.

Results
Male and female urban-dwelling adolescents had significantly (p < 0.05) higher systolic blood pressure (117.45 ± 21.53 mmHg and 114.82 ± 17.95 mmHg respectively) compared to their counterparts living in the non-urban areas (108.20 ± 12.12 mmHg and 106.03 ± 13.06 mmHg respectively), even after adjusting for age and height. Conversely, non-urban boys (but not the girls) had significantly (p < 0.05) higher diastolic blood pressure compared to their urban counterparts. Adolescents in the urban areas had higher BMI (20.74 ± 3.27 kg/m2 for males and 21.35 ± 3.37 kg/m2 for females) than those in the non-urban areas (20.33 ± 3.11 kg/m2 for males and 21.35 ± 3.37 kg/m2 for females) though the difference was significant (p < 0.05) only in the females. Blood pressures were found to increase with age, and to be associated with BMI.

Conclusion
These findings underscore the need for efforts to be made towards addressing adolescent blood pressure elevation (in both urban and non-urban areas) as they are a reflection of adult morbidity and mortality from hypertension and the associated disorders.