Acute effects of high-intensity interval training on retinal microvascular circulation in cancer patients and healthy controls: insight from the optical coherence tomography angiography.

BACKGROUND AND AIM: This study assessed retinal microvascular adaptations to a single high-intensity interval (HIIT) session using optical coherence tomography angiography (OCTA) in young cancer patients receiving vasculotoxic chemotherapy, compared to healthy controls of similar age.

METHODS

Cancer patients (age 33 ± 4 years, body-mass index = 22.6 ± 3.11 kg/m2, n = 12, 66% women) undergoing acute anti-cancer treatment and controls (30 ± 4 years, body-mass index = 23.6 ± 1.76 kg/m2, n = 12, 50% women) completed two laboratory visits. In the first, they performed a cardiopulmonary exercise test (CPET) until voluntary exhaustion. Within 48–72 h, participants completed a HIIT protocol (7 × 1 min at 90% peak power output, PPO) on a stationary cycle-ergometer. OCTA assessed retinal blood flow and acute vascular responses at three time points: baseline, immediately post-exercise, and 30 min post-exercise.

RESULTS

Cancer patients attained 31% lower PPO and had four minutes shorter CPET than controls, resulting in lower peak gas exchange values. During HIIT, groups exercised at different training loads (222 vs. 152 W). OCTAVA software analyzed acute responses in the deep retinal layer, superficial layer, and optic disc. A significant interaction effect was observed mainly in deep and superficial retina (η² ranged from 0.165 to 0.473, p < 0.01), not in the optic disc. The only significant correlation was between optic disc-derived m. tortuosity and V̇O₂ peak in cancer patients (r = 0.643, p = 0.024), not controls (p = 0.642).

CONCLUSION

Retinal microvascular reactivity was significantly altered following acute HIIT in patients undergoing chemotherapy, compared to healthy controls. Future research should evaluate chronic HIIT effects and explore the prognostic relevance of ocular microvascular adaptations in cancer care.