Body mass index associated with elevated blood pressure in Mexican school-aged adolescents.

Objective: To evaluate the relationship between blood pressure and body mass index among adolescents.

Methods: A 14-month period cross-sectional study was carried out among 2387 adolescents attending public schools in the state of Morelos, Mexico between 2005 and 2007. We measured blood pressure during four visits, obtaining elevated blood pressure prevalence according to the guidelines for children and adolescents of the United States National Educational Program on High Blood Pressure (at least three visits needed to assess elevated blood pressure on the basis of 95th percentile specific for gender, age and height). We used specific body mass index percentiles for age and gender. We employed multiple linear and Cox proportional hazards models to identify factors related to elevated blood pressure.

Results: The overall prevalence of elevated blood pressure was 3.9%. Multiple linear models showed that overweight subjects had systolic and diastolic blood pressures that were 5.1 and 2.5 mmHg higher, respectively, compared with adolescents with a normal body mass index, while obese subjects had 11.3 and 6.2 mmHg higher levels, respectively. Cox proportional hazards models indicated high risk of elevated blood pressure among overweight (RR, 3.6; 95%CI, 1.5-8.5) and obese subjects (RR, 14.2; 95%CI, 7.2-27.75) compared with adolescents with a normal body mass index.

Conclusion: Our results suggest that a higher body mass index is associated with elevated systolic and diastolic blood pressure levels, indicating the importance of incorporating strategies for ongoing screening and for promoting educational programs on healthy lifestyles to prevent hypertension in adolescents.