Obesity and Risk of Knee Osteoarthritis: A Case-Control Hospital-based Study of 372 Patients

This hospital-based case-control study explored whether the association between obesity and the risk of knee osteoarthritis (knee OA) exists.The study was conducted at an Orthopaedic Hospital Wamakko, a referral centre located in Sokoto, North-Western Nigeria for a period between January 2021 and December 2021.The cases with knee OA and unmatched controls were randomly selected.The inclusion criteria were adult patients aged >40 years with knee OA.The data was collected including the body mass index (BMI) in kg/m2 of each patient.Obesity was defined as BMI>29.9kg/m2.Data were analysed using SPSS version 26.There were a total of 372 patients in the study with 124 cases and 248 controls in a ratio of 1:2.The average age was 53.710.8(range 40 to 88 years).There were 165 (44.4%) males and 207 (55.6%) females.Among all the patients, there were 115 (30.9%) obese with 47 (40.9%) males and 68 (59.1%) females.Of the 257 (69.1%) non-obese patients, 118 (45.9%) were males and 139 (54.1%) were females.Among the 124 cases, there were 69 (55.6%) obese patients with 25 (36.2%)males and 44 (63.8%) females.The 55 (44.4%) non-obese patients among the cases were 24 (43.6%)males and 31 (56.4%)females.There was a statistical significance result between obesity and knee OA (OR=5.509,and P<0.0001).The study showed obese individuals have 5.509 times more risk of having knee OA compared with nonobese individuals indicating weight reduction as a key to prevention and treatment of knee OA.