The relationship between longitudinal serum leptin measures and measures of magnetic resonance imaging-assessed knee joint damage in a population of mid-life women
- 1Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, Michigan, USA
- 2Department of Radiology, University of Michigan Health System, Ann Arbor, Michigan, USA
- 3Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan, USA
- Correspondence to Dr Carrie Karvonen-Gutierrez, Department of Epidemiology, University of Michigan School of Public Health, 1415 Washington Heights, Room 1846, Ann Arbor, MI 48109, USA;
- Accepted 17 March 2013
- Published Online First 10 April 2013
Background and objective Serum leptin measures are associated with radiographic knee osteoarthritis, but no studies have examined leptin levels with respect to different measures of knee joint damage from MRI.
Methods Participants in the Michigan Study of Women's Health Across the Nation underwent bilateral knee MRIs at follow-up visit 11 for assessment of cartilage defects, bone marrow lesions, osteophytes, meniscal tears, synovitis and joint effusion. Serum leptin measures were available from baseline, follow-up visits 1 and 3–7.
Results Baseline serum leptin levels were associated with greater odds of having more severe knee joint damage at follow-up visit 11 after adjustment for age, smoking status, menopause status and body mass index residuals. The greatest effect was observed for osteophytes; a 5 ng/ml increase in baseline leptin was associated with 24% higher odds of having larger osteophytes (95% CI 1.17 to 1.32). Correlations with baseline serum leptin were greatest for MRI-assessed osteophytes (r=0.41), followed by effusion (r=0.32), synovitis (r=0.30), cartilage defects (r=0.28), bone marrow lesions (r=0.24) and meniscal abnormalities (r=0.21).
Conclusions Leptin levels 10 years prior to MRI assessment were associated with the presence of cartilage defects, bone marrow lesions, osteophytes, meniscal tears, synovitis and effusion among a population of middle-aged women. Understanding the role that leptin plays in the joint degradation process is critical for development of more targeted interventions for osteoarthritis.