Hyperbaric oxygen therapy mitigates cochlear damage induced by a high-fructose diet: a histopathological study in rats

Aims: Hearing loss, an increasing worldwide issue, has been associated with increased carbohydrate consumption. This study investigates the histopathological impact of a high-fructose diet (HFD) on cochlear structures and assesses whether hyperbaric oxygen therapy (HBOT) can mitigate those effects.Methods: Adult male Wistar rats were divided into four groups (n=8 each): control (standard diet, 10 weeks), HFD (60% fructose diet, 10 weeks), HBOT (standard diet+daily HBOT at 2.4 ATA for 1 h during weeks 9–10), and HFD+HBOT (60% fructose diet+HBOT in weeks 9–10). After 10 weeks, cochleae were took out and stria vascularis thickness, basilar membrane thickness, and inner/outer hair cell lengths were measured in basal, middle, and apical turns. Cochlear cross-sections stained with H&E and Masson’s trichrome, and evaluated histopathologically under light microscope. Results: Compared to controls, HFD-fed rats had thinner stria vascularis and basilar membranes in basal and intermediate turns and shorter hair cell lengths throughout all turns. The apical turn outer hair cell length and the middle and apical turns inner hair cell length increased statistically in HFD+HBOT rats compared to HFD alone. No significant changes were seen between HBOT-only and control groups. HFD induces considerable cochlear damage and cellular death in the organ of Corti in subjects. HBOT application somewhat mitigates these effects. Conclusion: A 10-week HFD induces region-specific cochlear structural degeneration in rats, and HBOT during the final two weeks partially reverses these changes. Future studies with larger sample sizes should include functional auditory assessments and explore underlying molecular mechanisms.