Objective: To examine the effects of smoking on cartilage loss and pain at the knee in those with knee osteoarthritis (OA).
Methods: We examined 159 men with symptomatic knee OA who participated in a 30-month, prospective, natural history study of knee OA. The more symptomatic knee was imaged using MRI at baseline, 15- and 30-months follow-up. Cartilage was scored using the WORMS semi- quantitative method at the medial and lateral tibiofemoral joint and at the patellofemoral joint. At baseline and follow-up visits, the severity of knee pain was assessed using a visual analogue scale (VAS) pain score (0-100 mm).
Results: Among the 159 men, 19 (12%) were current smokers at baseline. Current smokers were younger (mean age ± SD: 62 ± 9 vs. 69 ± 9 years) and leaner (mean body mass index (BMI): 28.9 & [plusmn] 3.2 vs. 31.3 ± 4.8 kg/m2) than men who were not current smokers. Adjusted for age, BMI and baseline cartilage scores, we found that men who were current smokers had an increased risk for cartilage loss, at the medial tibiofemoral joint (odds ratio (OR): 2.3, 95% CI: 1.0 to 5.4) and the patellofemoral joint (OR: 2.5, 95% CI: 1.1 to 5.7). Current smokers also had higher adjusted pain scores at baseline (60.5 vs. 45.0, p<0.05) and follow-up (59.4 vs. 44.3, p <0.05) compared with men who were not current smokers.
Conclusions: Men with knee OA who smoke sustain greater cartilage loss and have more severe knee pain than men who do not smoke.
- articular cartilage loss
- cigarette smoking
- knee MRI
- knee osteoarthritis
- knee pain