Abstract
Purpose :
Although the relationship between vital capacity (VC) and blood flow has been discussed, there needs to be a more detailed examination of the organic changes in blood vessels caused by ocular blood flow. We reported previously that the maintaining time of blood flow in the tissue area of the optic nerve head, the parameter BOT.T measured by laser speckle flowgraphy (LSFG), is strongly correlated with age and heart rate (HR), with the largest coefficient of HR in a multivariate regression analysis (Kobayashi, 2019, Sci. Rep.). In this study, we found in subsequent additional analyses that one of the factors affecting BOT.T and HR was VC. Therefore, we investigated the relationship between BOT.T and pulmonary function.
Methods :
We studied 210 healthy subjects (men = 166, age: 48.8± 8.8, women= 44, age: 49.9 ± 9.6, p= 0.321). We used multivariate analysis of variance (MANOVA) to investigate factors affecting BOT.T and HR. Pulmonary function was assessed using VC and %VC. The %VC is the ratio of VC to predicted VC, the standard VC calculated based on age, height, and gender. Subjects were divided into groups of 10 HR each (60 to less than 100), and BOT.T was compared between groups with higher %VC (>= 1) and lower %VC (< 1). Propensity score matching was performed within each group to reduce age bias.
Results :
The results of the MANOVA analysis indicated that age, gender, mean blood pressure (p < 0.001), height, VC, %VC (p < 0.01), and weight (p = 0.017) were the factors affecting BOT.T and HR. Comparisons within groups separated by HR indicated that only within the lowest HR group, 60 to 70, the group with the higher %VC had a significantly lower BOT.T than the lower %VC (P = 0.026).
Conclusions :
Only in the group with the lowest HR, the BOT.T of the group with higher %VC was significantly lower than that of the group with lower %VC. The condition of Lower HR and lower BOT.T becomingly is the one of good systemic circulation for normal subjects.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.