Twelve-year tracking of blood pressure in Korean school children: the Kangwha Study

Area of Science:

• Pediatrics
• Cardiovascular Health
• Epidemiology

Background:

• Longitudinal studies reveal varying degrees of blood pressure (BP) tracking across diverse populations.
• Understanding BP tracking in childhood is crucial for predicting adult cardiovascular health.
• The Kangwha Study provides a unique dataset for examining BP trends in Korean youth.

Purpose of the Study:

• To investigate the tracking of systolic and diastolic blood pressure in Korean school children.
• To quantify the degree of BP tracking from childhood (age 6) to late adolescence (age 17).

Main Methods:

• A longitudinal cohort of 219 Korean children (aged 6 in 1986) was followed annually until 1997.
• Blood pressure was measured using standard mercury sphygmomanometers, with diastolic BP recorded at the fourth Korotkoff sound.
• BP tracking was analyzed using time-lag correlation and McMahan's tracking index (tau), with jackknife methods for confidence intervals.

Main Results:

• Correlation coefficients for systolic BP ranged from 0.39-0.57, and for diastolic BP from 0.14-0.47.
• McMahan's tau for systolic BP was high (0.875 for males, 0.900 for females), indicating strong tracking.
• McMahan's tau for diastolic BP was also significant (0.983 for males, 0.800 for females), demonstrating robust tracking.

Conclusions:

• This study provides strong evidence for significant blood pressure tracking in Korean school children.
• Consistent BP levels observed from childhood through adolescence suggest potential long-term cardiovascular implications.
• Findings highlight the importance of monitoring BP in children for early identification of hypertension risk.