Keng A, et al. - This asymptomatic population-based cross-sectional study was carried out to determine magnetic resonance imaging (MRI)-detected prevalence of knee cartilage damage and to assess the link between body mass index (BMI) and cartilage damage. Findings demonstrated a high prevalence of MRI-detected knee cartilage damage. Data also reported a trend towards significance of BMI with cartilage damage severity. A 3-fold increased odds of cartilage damage ≥2 were reported in those with abnormal current BMI (≥25) vs those with normal BMI. The role of obesity in the pathogenesis of knee cartilage damage at an asymptomatic stage of disease was supported.

Methods

• This study included subjects, aged 40-79 years, without knee pain (n = 73), recruited as a random population sample.
• Study participants were assessed for BMI (kg/m²), including current BMI (measured), past BMI at age 25 (self-reported) and change in BMI.
• MRI was used to score knee cartilage semi-quantitatively (grades 0-4).
• In primary analysis, cartilage damage was defined as ≥2 (at least moderate) and in a secondary analysis as ≥3 (severe).
• A sensitivity analysis was also carried out by dichotomizing current BMI as <25 vs ≥25.
• Researchers used logistic regression to assess the association of each BMI variable with prevalent MRI-detected cartilage damage, adjusted for age and sex.

Results

• Researchers noted that among a total of 73 subjects, knee cartilage damage ≥2 and ≥3 was present in 65.4% and 28.7%, respectively.
• Data reported that the median current BMI was 26.1, median past BMI 21.6, and median change in BMI was a gain of 2.8.
• According to findings, current BMI had a non-statistically significant OR of 1.65 per 5 units (95% CI 0.93-2.92) for cartilage damage ≥2.
• Researchers found that for cartilage damage ≥3, current BMI displayed a trend towards statistical significance with an OR of 1.70 per 5 units (95% CI 0.99-2.92).
• In addition, results revealed no significant association of past BMI and change in BMI with cartilage damage.
• Data also showed that current BMI ≥ 25 was statistically significantly related to cartilage damage ≥2 (OR 3.04 (95% CI 1.10-8.42)), but not for ≥3 (OR 2.63 (95% CI 0.86-8.03)).