Original articlesPhysical activity and self-reported, physician-diagnosed osteoarthritis: is physical activity a risk factor?
Introduction
Osteoarthritis of the hip and knee represent two of the most important causes of pain and physical disability in community-dwelling adults 1, 2. This condition can be classified into two types: primary osteoarthritis (OA) is generally related to aging and heredity [3] while the specific etiology is not clear; secondary OA is caused by other diseases or conditions such as obesity, joint trauma, or repetitive joint use 3, 4, 5, 6, 7, 8. In addition, Hart et al. [9] found that hypertension, hypercholesterolemia, and high blood glucose are associated with both unilateral and bilateral knee OA independent of obesity and suggested that OA had an important systemic and metabolic component in its etiology.
While many types of physical activity involve repetitive joint use that may cause cartilage attrition, physical activity should be helpful in preventing OA in several ways. First, physical activity strengthens the muscular support around joints and thereby reduces the risk of joint injury. Second, physical activity prevents the joints from ‘freezing up’ and improves and maintains joint mobility. Third, physical activity helps to avoid obesity, a risk factor for some forms of OA. Finally, because cartilage has no blood vessels or nerves, mature cartilage cells receive nourishment only from the diffusion of substances through the cartilage matrix from joint fluid, and physical activity enhances this process [10]. However, persons who participate in competitive sports and certain types of occupational activity have been shown to be at higher risk for OA 11, 12, 13.
Regular physical activity is increasingly recognized as a major protective factor for coronary heart disease as well as a variety of related health benefits [14]. In the United States and other developed countries public health efforts are under way to encourage regular physical activity. Because leisure-time physical activity is widely promoted as a way to improve and maintain health, it is important to understand its potential effect on OA. There are a number of studies on the role of physical activity in the development of OA 5, 6, 7, 8, 9, 13, 15, 16, 17, 18, but the results are inconclusive. The purpose of this prospective study is to evaluate the association between physical activity and the incidence of self-reported physician-diagnosed OA, while controlling for other potential risk factors such as age, gender, body weight, current and past smoking, and consumption of alcohol and caffeine.
Section snippets
Study population
The study population consists of individuals aged 20 years or older examined at the Cooper Clinic, in Dallas, TX between 1970 and 1995. At each visit the individuals received a medical evaluation and clinical examination, and completed a detailed questionnaire that included items on health status, past medical history, and lifestyle habits. Individuals come to the clinic from all 50 states, are mostly white, well-educated, and in the middle to upper socioeconomic strata. Follow-up mail-back
Descriptive analyses
The study population consisted of individuals aged 20–87 years old. The median age was 44 years for men and 43 years for women. After excluding subjects who had a diagnosis of OA prior to the baseline visit and subjects who had missing information on the outcome variable, 16,961 individuals (12,888 (76%) men, 4,073 (24%) women) were included in this study. The average follow-up time was 10.9 years (SD = 6.13) for men, and 9.9 years (SD = 5.73) for women. Overall, there were 439 incident cases
Discussion
This prospective study on a large cohort of men and women, aged 20–87, provides additional knowledge about the relation of physical activity to knee and hip OA. We found a positive association between high levels of physical activity and OA among young men (age 20–49) after controlling for BMI, age, smoking, alcohol, and caffeine use. However, this association was not found for women or older men. The most probable explanation for these findings is that other unmeasured factors (such as the
Acknowledgements
We thank the Cooper Clinic physicians and technicians for baseline data collection, Carolyn E. Barlow for data and survey management, and H. W. Kohl III for the design and administration of the survey. Supported in part by U.S. Public Health Service research grant AG06945 from the National Institute on Aging, Bethesda, MD.
References (40)
- et al.
Obesity and osteoarthritis of the kneeevidence from the National Health and Nutrition Examination Survey (NHANES I)
Semin Arthritis Rheum
(1990) The epidemiology of knee osteoarthritisresults from the Framingham Osteoarthritis Study
Semin Arthritis Rheum
(1990)- et al.
Physical activity as a risk factor for osteoarthritis of the knee
Ann Epidemiol
(1994) - et al.
Clinical validation of self-reported osteoarthritis
Osteoarthritis Cartilage
(1998) - et al.
Caffeine content of common beverages
J Am Diet Assoc
(1979) - Murray CJL, Lopez AD. Disability: the invisible burden. In: A Summary of the Global Burden of Disease Cambridge:...
- et al.
An update on the epidemiology of knee and hip osteoarthritis with a view to prevention
Arthritis Rheum
(1998) - et al.
Evidence for a mendelian gene in a segregation analysis of generalized radiographic osteoarthritis
Arthritis Rheum
(1998) Epidemiology and genetics of osteoarthritis
Curr Opin Rheumatol
(1991)- et al.
Factors associated with hip osteoarthritisdata from the National Health and Nutrition Examination Survey (NHANES-I)
Am J Epidemiol
(1993)
Factors associated with osteoarthritis of the knee in the first National Health and Nutrition Examination Survey (NHANES-I)
Am J Epidemiol
Association between metabolic factors and knee osteoarthritis in womenthe Chingford Study
J Rheumatol
The effects of hydrostatic pressure on matrix synthesis in articular cartilage
J Orthop Res
Occupational activity and osteoarthritis of the knee
Ann Rheum Dis
Individual risk factors for hip osteoarthritisobesity, hip injury, and physical activity
Am J Epidemiol
Sports and osteoarthritis of the hipan epidemiologic study
Am J Sports Med
Physical Activity and HealthA Report of the Surgeon General
The prevalence of gonarthrosis and its relation to meniscectomy in former soccer players
Am J Sports Med
Is running associated with degenerative joint disease?
JAMA
Long-distance running, bone density, and osteoarthritis
JAMA
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