Knee osteoarthritis and associated cardio-metabolic clusters in a tertiary hospital in Nigeria

Osteoarthritis (OA) of the knee is the most common type of arthritis all over the world. Obesity is the strongest modifiable risk factor and causes OA through a combination metabolic factors and mechanical loading. This study aimed to determine the frequency of metabolic syndrome (Mets) among patients with knee OA and its relationship with pain and functional status. This was a descriptive hospital-based cross-sectional study involving patients with knee OA. Pain was measured using a 0–10 numeric rating visual analog scale (VAS). Functional status was assessed using Steinbrocker’s functional classification. Metabolic syndrome was diagnosed using the International Diabetic Federation criteria. Radiographs of both knees were taken and graded using Kellgren and Lawrence scale. Relationship of pain and functional status with obesity and Mets was assessed using Pearson’s correlation. A p value of < 0.05 was considered significant. Two hundred and forty-four patients with knee OA comprising 63 (25.8%) males and 181 (74.2%) females were recruited. The median age was 50 years (range 18–73 years). Mets was diagnosed in 146 (59.8%). Obesity, diabetes, and hypertension were present in 154 (63.1%), 40 (16%), and 144 (59%) patients, respectively. Severe pain at first visit was present in 216 (88.5%) patients of which 128 (52.4%) had Mets compared to 85 (36.1%) without Mets (χ2 = 2.40, p = 0.361). Two hundred and four (83.6%) had Steinbrocker’s functional classes II and III. Waist circumference was higher in patients with Mets (p = 0.025) but age (p = 0.092), BMI (p = 0.831), VAS (p = 0.361), and functional class (p = 0.401) were similar in those with and without Mets. Body mass index showed significant association with severity of pain (p = 0.017) but not with functional class (p = 0.138). Kellgren and Lawrence radiographic grades III and IV were documented in 288 (48.5%) and 136 (27.2%) knees, respectively. A higher BMI correlated with more severe radiographic grading for the right (p = 0.043) and left (p < 0.001) knees, respectively. Mets is prevalent (59.8%) among Nigerians with knee OA, and those with Mets have higher waist circumference. Significant association was observed between BMI with pain and Kellgren-Lawrence (KL) grade. Mets was not associated with pain, function, or KL grade.