LAUSR

Background: Carotid intima-media thickness (cIMT) is a well-known marker of atherosclerosis and future cardiovascular events such as myocardial infarction. The 6-minute walk test (6MWT) is a widely used method for evaluating aerobic fitness and functional exercise capacity. However, no studies have assessed the relationship between 6MWT distance and cIMT in older adults. Therefore, this study aimed to examine the association between aerobic fitness expressed as the 6MWT distance and cIMT in older Korean adults. Methods: We retrospectively reviewed raw data of the 2014-2015 Korean Institute of Sports Science Fitness Standards, a national fitness measurement project in Korea. Participants older than 65 years and who underwent 6MWT and cIMT measurements were included in the study. The 6MWT was performed, and the total distance that the participants covered in 6 min was measured. The cIMT was defined as the distance between the lumen-intima and the media-adventitia interfaces. The cIMT was measured at the proximal 1 cm of the right common carotid bulb. A high-resolution ultrasound device with a frequency of ≥11.4 MHz was used for cIMT measurement. We adjusted the data for multiple confounding factors. Statistical analyses were performed using generalized linear regression analysis. Results: Overall, 608 participants were included (male, n=302 [49.67%]; female, n=306 [50.32%]). The mean participant age was 70.99±4.22 years (male 71.48±4.40 years, female 70.50±3.98 years). The mean cIMT was 0.74±0.18 mm (male 0.78±0.19 mm, female 0.70±0.16 mm). The mean 6MWT distance was 479.15±92.82 m (male 499.96±85.88 m, female 458.60±94.94 m). After multivariable adjustment, the highest 6MWT distance tertile was inversely associated with cIMT (β [95% confidence interval (CI)]: -0.042 [-0.080, -0.005]; p=0.027) versus the lower tertiles. In the subgroup analysis, the male group did not show a significant association with cIMT, while the highest 6MWT distance tertile in the female group showed a significant inverse association with cIMT ((β [95% CI]: -0.049 [-0.098, -0.001]; p=0.049). Conclusion: Our results suggest that there is an inverse relationship between 6MWT distance and atherosclerosis, expressed as cIMT, in older Korean adults.