Decreased retinal capillary density as a beneficial response to 24-week high-speed circuit resistant training in healthy older adults

Abstract

Purpose: To determine the changes in retinal microvascular density after a 24-week high-speed circuit resistance training program (HSCT) in healthy older adults.

Methods: Thirty healthy older adults were recruited and randomly assigned to either a training group (HSCT) or a non-training (CON) group. Fifteen subjects (age 73.3 ± 7.76 yrs) in the HSCT group exercised three times per week on non-consecutive days for 24 weeks. Fifteen subjects in the CON group (age 72.2 ± 6.04 yrs) did not have formal physical training. Both eyes of each subject were imaged using optical coherence tomography angiography (OCTA) at baseline and at the 24-week follow-up. The vessel densities of the retinal vascular network (RVN), superficial vascular plexus (SVP), and deep vascular plexus (DVP) were measured.

Results: There were no demographic differences between the study groups. There were significant decreases in the retinal vessel densities of RVN, SVP and DVP in the HSCT group (P < 0.05). However, there were no significant changes in all three vascular measurements in the CON group (P > 0.05), although the changes showed a decreasing trend. The decreased vessel densities were doubled in the HSCT group in comparison to the CON group. However, the differences between groups did not reach a significant level (P > 0.05).

Conclusions: This is the first study to reveal the decreased retinal vessel densities as a possible imaging marker for the beneficial effects of the 24-week HSCT program in older adults.

Keywords: High-speed circuit resistance training; Optical coherence tomography angiography; Retinal microvascular density.