Does smoking protect against osteoarthritis?

Abstract

While studying knee osteoarthritis (OA) in the first Health and Nutrition Examination Survey, we unexpectedly found a protective association between smoking and OA. After adjustment for age, sex, and weight, smokers had a significantly lower rate of OA than did nonsmokers, and heavier smokers were less likely to have the disease than were light smokers. To test this association in a separate study and see if it was due to confounding factors, we looked at the Framingham Osteoarthritis Study, a study of elderly members of the Framingham Heart Study cohort. We evaluated whether the presence of knee OA in 1983-1985 was related to smoking status at the first Framingham examination, 36 years earlier. Subjects who had been smokers at examination 1 had a lower rate of OA (190 of 679,28%) than did nonsmokers (276 of 736,37.5%). In an analysis adjusted for age, sex, and weight, heavy smokers had a modestly lower risk of developing knee OA than did nonsmokers (relative risk 0.81). Also, the adjusted risk of severe OA was less in heavy smokers than in nonsmokers (relative risk 0.73). The negative association with OA persisted when we examined the average cigarette consumption over the first 10 years of the Framingham study. Furthermore, after controlling for age, sex, weight, knee injury history, sports activity history, physical activity level, coffee and alcohol consumption, and weight change after examination 1, and after modeling weight and age in a nonlinear manner, smoking remained a significant protector against later knee OA. It appears that smoking or some unidentified factor correlated with smoking modestly protects against the development of knee OA.With a recent surge of interest in the epidemiology of osteoarthritis (OA) has come a search for factors that might prevent the progression of cartilage damage into manifest disease. While studying the link between radiographically evident knee OA and obesity and occupation in the first Health and Nutrition Examination Survey (HANES I) (I), we unexpectedly found a modest, statistically significant protective association between smoking and OA. This association persisted after statistical adjustments for age, sex, and weight. A literature search revealed little previous research concerning smoking and OA, although smoking has been suggested as a risk factor for low back pain (2,3).We sought to confirm this link between smoking and OA in an entirely separate sample, the Framingham Osteoarthritis Study (FOS). While both the HANES I and the FOS are population-based studies, the two are different in that the HANES I study was of a nationwide sample, whereas the FOS sample was composed of persons living in Framingham, a predominantly white, middle-class Boston suburb. Furthermore, the FOS subjects were elderly, whereas HANES I subjects were middle-aged. Finally, in HANES I, smoking and OA were assessed concur-

Risk factors for incident radiographic knee osteoarthritis in the elderly. The framingham study

“…In cross-sectional studies, others (4,5,20,31) have also reported that subjects with OA are less likely to be smokers than are their matched controls. However, this finding is not universal (32).…”

“…Cigarette consumption was assessed at each examination and defined as the mean number of cigarettes smoked per day over examinations [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. We also evaluated current cigarette smoking at examination 18.…”

The causal role of smoking on the risk of hip or knee replacement due to primary osteoarthritis: a Mendelian randomisation analysis of the HUNT study

“…No curative treatment for OA is available, which places emphasis on identifying modifiable risk factors for disease prevention and treatment of early OA 2 . The results of observational studies suggest that smoking could have a protective effect on the development of OA 3,4 and subsequent hip and knee replacement [5][6][7] . Although results from in vitro data have indicated a beneficial effect of nicotine on chondrocyte function, the mechanisms remain unclear 8,9 .…”

Risk Factors of Symptomatic Knee, Hand and Hip Osteoarthritis in a Suburban Area of İzmir City

“…Felson et al (48) have reported that both male and female smokers had less OA development risk than the non-smoker group. They also suggested that the smoker population's low BMI and low amount of load taken by the knee could also decrease OA rates.…”