Low-intensity vibration increases cartilage thickness in obese mice

Area of Science:

• Orthopaedic Research
• Osteoarthritis (OA) Pathophysiology
• Biomechanics and Tissue Engineering

Background:

• Obesity is a significant risk factor for developing osteoarthritis (OA).
• Understanding how diet-induced obesity affects articular cartilage development and the potential protective effects of mechanical stimulation is crucial for OA prevention strategies.

Purpose of the Study:

• To investigate if a high-fat diet (HF) compromises articular cartilage thickness in young mice.
• To determine if low-intensity vibration (LIV) can protect articular cartilage in a diet-induced obesity mouse model.
• To assess the long-term effects of HF diet and LIV on articular cartilage and subchondral bone integrity.

Main Methods:

• Five-week-old male C57BL/6 mice were fed a regular diet (RD) or high-fat diet (HF) for 6 weeks, with one HF group receiving concurrent low-intensity vibration (HFv).
• An extended study involved HF diet and LIV for 6 months.
• Articular cartilage and subchondral bone were analyzed using contrast-enhanced μCT and histology; gene expression (aggrecan, MMP-13) was quantified via real-time PCR.

Main Results:

• Contrary to hypothesis, HF diet did not significantly reduce cartilage thickness compared to RD.
• LIV treatment increased cartilage thickness in HF mice, an effect sustained in the long-term study.
• HF diet reduced aggrecan expression and increased subchondral bone thickness (early OA sign), while LIV counteracted these effects and reduced MMP-13 expression.

Conclusions:

• Low-intensity vibration (LIV) protects articular cartilage thickness and subchondral bone integrity in the context of a high-fat diet.
• Dynamic loading via LIV may be a viable strategy to mitigate joint damage associated with obesity-induced OA.
• LIV application shows potential for preserving joint health under metabolic stress.