Association between obesity and risk of knee osteoarthritis

The study was designed to investigate the association between obesity and the risk of knee osteoarthritis, recruiting 400 knee osteoarthritis patients and an equal number of controls. After the informed consent, diagnosed patients from Jinnah Post Graduate Medical Centre, Karachi were included as "cases". Age-matched individuals without the disease were included as "controls". Sociodemographic data were taken from each participant. Characteristics were compared by odds ratio and chi-square using SPSS 20 software. Obesity (OR 3.29; 95% CI 2.40-4.51), female gender (OR 2.87; 95% CI 1.94-4.25) and family history (OR 3.61; 95% CI 2.69-4.85) were found to be significantly associated with osteoarthritis (p<0.001). Highest OR was found in case of stair climbing >10 flights/d (OR 6.08; 95% CI 4.16-8.89; p<0.001), whereas heavy lifting (>25 kg/d for > 4 hr) was observed as another major factor with OR of 5.24 (95% CI 3.54-7.75; p<0.001) that elevates the risk. The study concluded that obesity is significantly associated with osteoarthritis and obese individuals (BMI >= 25 kg/m(2)) are at high risk of disease development. Furthermore, family history, prolonged standing (>2 h/d for >= 1 yr), heavy lifting (>25 kg/d for > 4 hr), stair climbing (>10 flights/d) and sitting on the floor (>= 5 h/d) might also be associated with knee osteoarthritis.