What is the evidence for avocado-soybean unsaponifiables in the treatment of osteoarthritis of the knee?
AMSTAR Rating
Summary
Patient Population:
58.6% of enrolled participants had knee OA, the remainder had OA of the hip. Proportion of female participants was 64% overall (range: 37-81%). Reported mean age ranged from 63.2 – 64.9 years.
Intervention:
Avocado-soybean unsaponifiables (ASU) treatment: 1 capsule/day of 300 mg ASU.
Comparison:
ASU was compared to a matching placebo. There were 4 trials identified that met all inclusion criteria. Studies were assessed as high quality overall. The weighted average Jadad score was 4.5.
Outcome:
- Pain: ASU vs. placebo (4 studies) – significant difference in favour of ASU (ES=0.39; 95% CI 0.01 to 0.76; p=0.04); however, this analysis was associated with significant heterogeneity (I2=83.5%).
- Pain: individuals with knee OA might experience more pain relief (ES=0.99; 95% CI 0.54 to 1.44) than individuals with hip OA (ES=-0.44; 95% CI-1.05 to 0.17).
- Function: ASU vs. placebo (4 studies) – significant difference in favour of ASU (ES=0.45, 95% CI 0.21, 0.70, p=0.0003); however, this analysis was associated with significant heterogeneity (I2=61%).
- Self-reported “response to treatment”: All 4 studies also included a self-reported assessment of response. This was presented as a dichotomous outcome. As for the other 2 outcomes, there was a significant effect in favour of ASU when compared to placebo, such that there were greater odds of response to treatment for individuals assigned to ASU (OR=2.19, 95% CI 1.24, 3.86, p=0.007; I2=68.9%). This corresponds to NNT=6.
