Tracking of Blood Pressure from Adolescence to Middle Age: The Dormont High School Study

Methods. Tracking of blood pressure was studied in a cohort of 86 men and 116 women, initially examined at mean age 17 years and re-examined at mean ages 34 and 47 years in the Dormont High School Follow-up Study. Results. Correlations for systolic blood pressure (men vs women, P < 0.05) were r=0.42 vs r=0.39 between mean ages 17 and 34 years; r=0.38 vs r=0.54 between mean ages 34 and 47 years; and r=0.27 vs r=0.24 between mean ages 17 and 47 years. For diastolic blood pressure, the correlations were lower, but were higher among women than men, and were higher between mean ages 34 and 47 years (r=0.44 for men and r=0.54 for women, P < 0.001) than at earlier ages. The correlations for weight were higher than those for blood pressure (men vs women, P < 0.001): r=0.64 vs r=0.59 between mean ages 17 and 34 years; r=0.88 vs r=0.81 between mean ages 34 and 47 years; and r=0.58 vs r=0.49 between mean ages 17 and 47 years. With increase in age and length of follow-up, there was a stronger tendency for those in the extreme tertiles of the blood pressure distribution to maintain their ranks. The significance and magnitude of the blood pressure correlations remained essentially unchanged after adjustment for weight and its changes. However, weight was related to the changes in blood pressure tracking status, but this varied with age. Conclusion. These data suggest that the age and gender differences in the degree of blood pressure tracking may be a function of the tracking of weight as well as a reflection of the gender difference in the consistency of the relationship of blood pressure to weight at different ages.