To assess the tracking of blood pressure (BP) from middle age to old age.Methods:
The Chinese Multi-Provincial Cohort Study—Beijing Project included 4,149 participants aged 35–64 years at baseline in 1992 and followed up till 2012. Repeated BP measurements recorded in either two examinations in 1992, 2002, 2007, or 2012 were used in this analysis. Pearson correlation was used to measure the strength of association between BP measurements at different ages, and cross-tabulated quintiles of BP levels with advancing age was used to quantify the likelihood of maintaining BP in either the top or bottom quintile at later measurements.Results:
The correlation coefficients decreased in magnitude with increasing length of time between readings from the same age. The greatest tracking coefficients for systolic BP and diastolic BP over 10 years was in men aged 45–54 years and in women aged 65–74 years. At the same time interval between measurements, the correlation coefficients in women were greater than in men for systolic BP and diastolic BP, though were smaller than men for pulse pressure among those older than 55 years. The relative likelihood of tracking was greater for systolic BP than diastolic BP and decreased in magnitude with increasing length of time between readings from the same age. Compared with men, women in the top or bottom of systolic BP quintile were more likely to maintain their position up to 20 years, except that women aged 45–64 years were less likely to remain at the top quintile in a 15-year interval.Conclusion:
Tracking of BP is noted from middle age to old age, and it is more evidenced for systolic BP than diastolic BP and greater for women than for men.