Osteoarthritis of the knee joint in the obese patient: Do metabolic factors play a role?

Introduction: Osteoarthritis (OA), a disease process characterized by progressive softening of the articular cartilage, sclerosis of subchondral bone, and cyst formation often affects the knee joint. Although OA has traditionally been interpreted as wear and tear, its etiology is now thought to be multifactorial with both biomechanical and metabolic factors implicated. Of the metabolic factors, leptin a glycosylated peptide hormone produced by the adipocytes has received major attention because of its correlation to body size. The aim of this study was to determine the correlation between the clinical severity of knee OA and serum leptin in obese patients. Materials and Methods: This was a prospective study; recruiting 100 patients (50 obese and nonobese patients) with OA of the knee joint. The severity of knee OA was ascertained using the WOMAC scoring system, and serum leptin of all patients was determined. Results: The age group most commonly affected by knee OA was 51–60 years. The mean serum leptin level in nonobese patients was 4.88 ± 5.08, compared to 20.11 ± 15.04 in obese patients. There was a statistically significant correlation between the severity of knee OA (using WOMAC score) and serum leptin level; P = 0.001. Conclusion: This study shows a statistically significant positive correlation between serum leptin and severity of clinical symptoms in obese patients with knee OA.