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

Abstract

Objective. Knee osteoarthritis (OA) is highly prevalent, especially in the elderly. Preventive strategies require a knowledge of risk factors that precede disease onset. The present study was conducted to determine the longitudinal risk factors for knee OA in an elderly population.Methods. A longitudinal study of knee OA involving members of the Framingham Study cohort was performed. Weight-bearing knee radiographs were obtained in 1983-1985 (baseline) index increased the risk of OA (OR = 1.6 per 5-unit increase, 95% CI 1.2-2.2), and weight change was directly correlated with the risk of OA (OR = 1.4 per 10-lb change in weight, 95% CI 1.1-1.8). Physical activity increased the risk of OA (for those in the highest quartile, OR = 3.3, 95% CI 1.4-7.5). Smokers had a lower risk than did nonsmokers (for those who smoked an average of 1 1 0 cigarettedday, OR = 0.4, 95% CI 0.2-0.8). Factors not associated with the risk of OA included chondrocalcinosis and a history of hand OA. Weight-related factors affected the risk of OA only in women.Conclusion. Elderly persons at high risk of developing radiographic knee OA included obese persons, nonsmokers, and those who were physically active. The direction of weight change correlated directly with the risk of developing OA.Osteoarthritis (OA) is the most common joint disease, especially in the elderly. However, partly because of the slow time course of disease development, no substantial longitudinal studies of risk factors for the disease have been performed. Knowledge of the risk factors for knee OA has been derived from crosssectional studies.Similar to many chronic diseases, the pathogenesis of OA is likely to be multifactorial. Risk factors consistently associated with the disease in cross-sectional studies include older age, female sex, and being overweight (1). In cross-sectional studies, the OA could develop first, leading a person to become sedentary and to gain weight. We have reported that higher weight in early life predisposes patients to knee OA (2), and that weight loss lowers the risk of developing symptomatic knee OA (3). Both results were based on a one-time assessment of OA occurrence (3). We (4) and others ( 5 )

The association of body mass index and osteoarthritis of the knee joint: An examination of genetic and environmental influences

“…There is a dose-response relationship between excess weight or obesity and knee OA (5). These crosssectional data have been confirmed by longitudinal data from the Framingham Study (11,12), the Chingford study (13), as well as the Baltimore Longitudinal Study of Aging (14).…”

Health consequences of obesity in the elderly: a review of four unresolved questions

“…108 Several longitudinal studies support a role for overweight and obesity in the onset of OA. [109][110][111][112][113] Being overweight at an average age of 37 y increased the risk of developing knee OA at a mean age of 73 y; 109 approximately 25% of subjects normal-weight at baseline developed OA against 50% of overweight subjects. 109 In another recent study, male medical students with a BMI higher than 25 kg/m 2 , between the ages of 20 and 29 y, had a three-fold increased risk of developing symptomatic knee OA by the time they reached age 60 y.…”

Radiologic assessment of age‐related knee joint space changes in women: A 4‐year longitudinal study

“…The natural history of OA remains poorly studied for several reasons. First, many previous epidemiologic studies were conducted in elderly or osteoarthritic populations (1,2). Second, in most studies (3)(4)(5), knee radiographs were obtained with legs in full extension, a technique adequate to analyze bony changes such as osteophytes and sclerosis, whereas joint space width (JSW) is better assessed on semiflexed radiographs with standardized procedures (6).…”