Abstract
Objective: The objective of this study was to correlate osteoarthritis with BMI, age and gender.
Methods: This case control study was carried out at Shifa College of medicine/ Shifa International Hospital Islamabad for the duration of one year. Formal approval from the Institutional Review Board and Ethics Committee of Shifa College of Medicine/ Shifa International Hospital Islamabad was taken. The non-probability sampling technique was used. After getting informed consent, subjects were divided in two groups. Group A included 50 patients of osteoarthritis, who were diagnosed on the basis of radiographs by using Kellgren-Lawrence grading system. The radiographs were reported by the radiologist and orthopedic surgeon and Group B included 50 controls. Height and weight of patients and controls were recorded. Body mass index was calculated by applying formula BMI = Weight in kilograms / (Height in meters)2. Patients were divided in different age groups on the basis of gender, number of joints involved and severity of disease. Student t-test was used for continuous variables and number and percentages for categorical variables.
Results: The results of this study show that body mass index is significantly associated with osteoarthritis as compared with controls (p value 0.000). Further analysis of data reveals that it is a progressive disorder and it is more common in females especially in old age. 86 % of the cases in younger age group (40-50 yrs) have unilateral joint involvement however in older age group (71-80 yrs) 100% of patients have bilateral joint involvements. Similarly 57 % of the patients have moderate disease in a younger age group as compared to 70 % of patients having severe (grade 4) disease in a older age group.
Conclusion: Over weight and obesity is strongly associated with OA in our population, therefore weight reduction can decrease the disease burden and will help in minimizing morbidity associated with OA.

Key words: Osteoarthritis, obesity, Body mass index (BMI)