Search

Objective: Increased levels of pro-inflammatory cytokines are associated with the release of degradative enzymes leading to osteoarthritis (OA) development. Although physical exercise (PE) is generally recognized as beneficial for OA symptoms, excessive training workload and eccentric muscular exercise have increased OA risk. Here, we investigated the effects of excessive exercise workload and exercise type on systemic inflammation and knee joint OA.Methods: Mice were divided into five groups: sedentary (SED), uphill training (TRU), downhill training (TRD), excessive uphill training (ETU), and excessive downhill training (ETD) for an 8-week training intervention protocol.Results: ETD group had increased pro-inflammatory cytokines in serum, vastus lateralis (VL), and vastus medialis (VM) muscles, while ETU group mice had increased cytokine levels in the VL and VM. Total knee joint OARSI score were more significant in ETD group compared to SED and TRU groups. They were also more meaningful for the medial tibial plateau of ETD group compared to SED group. MMP-3 and cleaved Caspase-3 were higher in the ETD group than the SED and TRU group, while Adamts-5 was higher in the ETD group than the SED group. TRU group had increased PRG-4 levels compared to ETU and ETD group. ETD group had decreased total bone volume, trabecular bone volume, and cortical thickness compared to SED group.Conclusion: Excessive downhill training induced a chronic pro-inflammatory state in mice and was associated with early signs of cartilage and bone degeneration that are clinical indicators of knee OA. [ABSTRACT FROM AUTHOR]

Oligofructose prebiotic fiber supplementation has been reported to mitigate the effects of a high fat/high sucrose diet and reduce knee joint degeneration in male rats. However, few studies investigated the development of osteoarthritis and bone lesions as a function of sex and in joints other than the knee. This study was aimed at to quantifying the effect of a HFS diet and prebiotic fiber supplementation on shoulder joint health in male and female Sprague-Dawley rats. Rats were randomized into 6 groups: 2 groups fed a chow diet: Chow-Male n = 11, Chow-female n = 12; 2 groups fed a HFS diet: HFS-Male n = 11, HFS-Female n = 12; and 2 groups fed a prebiotic fiber supplement in addition to the HFS diet: Fiber-Male n = 6, Fiber- Female n = 12. After 12 weeks, shoulder joints were histologically assessed for OA. Body composition, serum lipid profile, insulin resistance and fecal microbiota were also assessed. Shoulders in male and female rats appear to be protected against degeneration when exposed to a HFS diet. Male rats developed bone lesions while females did not. Fiber supplementation was more effective in males than in females suggesting that fiber supplementation may have sex-specific effects on the gut microbiota., (© 2024. The Author(s).)