Abstract
Purpose:
To investigate the impacts of longitudinal changes in BP on retinal microvasculature, in a population of middle-aged and elderly Chinese with or without hypertension
Methods:
Subjects aged 40 years or older, with or without hypertension were recruited in a prospective cohort study, in Guangzhou, southern China, in 2008. Resting blood pressure was measured annually throughout 5-year follow-up period, using the same standardized protocols and equipment. Retinal vascular caliber was measured at the last year in 2012, using standard fundus photographs and validated software. Participants with at least three sequences of BP measurements were included for statistical analysis. Associations of retinal vascular caliber with the longitudinal trends (measured as the slope on linear regression) and variability (measured as the root mean square error and standard deviation) in systolic and diastolic BP (SBP and DBP) were examined using linear regression models.
Results:
A total of 4037 individuals (1674 hypertensives and 2363 normotensives at baseline) were available for analysis. In a multivariable linear regression model, a rising BP trend was found associated with narrowed retinal arteriole in the hypertensives (β=-0.52 and -0.70, P<0.001 and P=0.001 for the SBP and DBP trend, respectively). The negative association of retinal arteriolar caliber with the longitudinal DBP trend, but not the SBP trend, was also found statistical significant in the normotensives (β=-0.35, P=0.036). Measurements of BP variability were not found statistically significant in association with retinal vascular caliber (all P>0.05).
Conclusions:
An annual rising trend in BP was associated with narrowed retinal arteriole in both hypertensive and normotensive Chinese. The results indicate that, in terms of blood pressure management, it is important to maintain BP stability to protect microvascular damage
Keywords: 465 clinical (human) or epidemiologic studies: systems/equipment/techniques