(HealthDay News) — The inflammatory adipokine leptin may have a mediating effect on the relationship between body weight and knee osteoarthritis in older adults, according to research published in Arthritis & Rheumatology.
Angela Fowler-Brown, MD, MPH, of the Beth Israel Deaconess Medical Center in Boston, and colleagues analyzed baseline data for 653 participants, aged 70 years or older, enrolled in the population-based Maintenance of Balance, Independent Living, Intellect, and Zest in the Elderly Boston Study.
The effect of leptin on the relationship between BMI and knee osteoarthritis was assessed.
The researchers found that the prevalence of knee osteoarthritis among the participants was 24.7%; average BMI was 27.5 and average leptin level was 589 pM. An increase of BMI was associated with a 32% increase in risk for knee osteoarthritis. A 200 pM increase in serum leptin levels was associated with an 11% increase in risk for knee osteoarthritis.
Calculations of the ratio of the standardized coefficients for the indirect:total effect using the product-of-coefficients method indicate that about one-half of the total effect of BMI on knee osteoarthritis may be mediated by the serum leptin level.
Estimates of the 95% confidence intervals for this effect and mediation analysis suggest that the leptin effect on the relationship between BMI and knee osteoarthritis may be statistically significant.
“We found that almost half of the association between elevated BMI and knee [osteoarthritis] could be explained by the inflammatory adipokine leptin,” the researchers wrote.