Individual risk factors for hip osteoarthritis: obesity, hip injury, and physical activity

Obesity, overweight and patterns of osteoarthritis: the Ulm Osteoarthritis Study

The objective of this study was to assess the association between obesity and osteoarthritis (OA) of the knee, hip, and hand. OA patterns were studied in 809 patients with knee or hip joint replacement due to OA. Patients with OA were categorized as having bilateral or generalized OA according to the presence of radiographic OA in the contralateral joint or different finger joints, and as normal weight, overweight, or obese according to their body mass index (BMI). Odds ratios (OR) and 95% confidence intervals (CI) for relative weight and OA patterns were estimated with multivariable logistic regression. Eighty-five percent of participants had bilateral OA, 26% had generalized OA, and 31% were obese. Obesity (BMI >/= 30 kg/m(2); OR = 8.1; 95% CI: 2.4-28) and overweight (BMI >/= 25 kg/m(2); OR = 5.9; 95% CI: 2.0-18) were strongly associated with bilateral knee OA. No association between obesity and bilateral hip OA (OR = 0.7; 95% CI: 0.3-1.7) nor generalized OA (OR = 1.1; 95% CI: 0.6-2.1) was observed. Obesity seems to be a mechanical rather than a systemic risk factor for OA with the knee joint being especially susceptible.

Physical activity and self-reported, physician-diagnosed osteoarthritis: is physical activity a risk factor?

This prospective study evaluated regular physical activity and self-reported physician-diagnosed osteoarthritis of the knee and/or hip joints among 16,961 people, ages 20-87, examined at the Cooper Clinic between 1970 and 1995. Among those aged 50 years and older, osteoarthritis incidence was higher among women (7.0 per 1000 person-years) than among men (4.9 per 1000 person-years, P = 0.001), while among those under 50 years of age, osteoarthritis incidence was similar between men (2.6) and women (2.7). High levels of physical activity (running 20 or more miles per week) were associated with osteoarthritis among men under age 50 after controlling for body mass index, smoking, and use of alcohol or caffeine (hazard ratio = 2.4, 95% CI: 1.5, 3.9), while no relationship was suggested among women or older men. These findings support the conclusion that high levels of physical activity may be a risk factor for symptomatic osteoarthritis among men under age 50.

Women and the orthopaedic surgeon. Changing the relationship

Women are disproportionately disabled by musculoskeletal conditions. For biologic and lifestyle reasons, musculoskeletal health is one of the areas of medicine in which the differences between men and women are most marked. Thus, an approach tailored to women, not just an approach based on what has worked for men, often is needed. How orthopaedists treat women will become an even more pressing issue in the years ahead. Demographic trends predict that the majority of senior citizens will be women in whom chronic conditions frequently involve a musculoskeletal problem. Even at earlier ages, women will present more frequently with musculoskeletal conditions because they participate in a broader range of sports and careers. The current study presents a lengthy list of action items that the orthopaedic surgeon should consider as he or she approaches the treatment of women. Many of these items involve anticipating musculoskeletal problems, and convincing patients to take appropriate preventive steps. Because so many patients are treated by physicians who are not orthopaedists for their musculoskeletal problems, a successful preventive approach presents orthopaedists with the opportunity to win the confidence and respect of a new generation of patients.

Physical activity in the prevention and treatment of other morbid conditions and impairments associated with obesity: current evidence and research issues

PURPOSE

To evaluate the current status of knowledge concerning the effects of physical activity in the treatment and prevention of obesity- related problems, including cancers of the colon, breast, uterus, and prostate; gallstones; osteoarthritis; back pain; sleep apnea; reproductive abnormalities; and impaired health-related quality of life.

DESIGN

A Medline literature search on the effects of physical activity in the above conditions was conducted. Only studies with some measure of weight and a description of the type of physical activity were included.

RESULTS

No controlled randomized trials of exercise in the treatment of any of the studied conditions in obese patients were identified. Most of the epidemiologic studies reviewed were beset with severe methodological weaknesses. Most of the 18 studies on physical activity and colon cancer risk showed a protective effect that in some studies appeared to be greater than expected by weight loss alone. Some but not all studies of hormone-dependent cancers and gallstones showed a protective effect for physical activity. There were insufficient data on the role of exercise for the other morbid conditions studied.

CONCLUSION

The scarce data available on the role of physical activity in the prevention of obesity-related chronic conditions listed above suggest a protective role that needs to be examined further in studies with improved methodologies. Well-designed intervention trials are needed to assess the role of physical activity in the treatment and long-term outcome of obese patients with these co-morbid conditions.

Osteoarthritis: Update on Pathology, Pathogenesis and Treatment

Osteoarthritis (OA) is a joint disorder that is characterized by increased degradative and decreased synthetic processes. The pathogenetic factors that have been demonstrated to influence the progression of OA are cytokines and nitric oxide. This new information serves to further elucidate the factors involved in the etiology of osteoarthritis and will aid in the development of pharmacological tools to treat this disease. As our understanding of the pathogenesis of OA grows, so does our appreciation that it is not simply a disease of passive joint degeneration. Unfortunately, therapies aimed at modifying the progression of the disease remain frustratingly difficult to identify. Primary therapy for OA thus is still largely aimed at controlling the symptoms of the disease while minimizing drug side effects. New agents with the potential to slow disease progression are beginning to emerge however. These will be discussed along with the agents that should be used first line to control symptoms.

Epidemiology of the rheumatic diseases

Epidemiologic studies of rheumatic diseases can be broadly divided into those that describe the occurrence of specific disorders, those that attempt to quantify the role of putative risk factors for disease occurrence, and those that define the outcome and factors associated with it. Studies in this area have tended to be hypothesis testing rather than generating new etiologic or related hypotheses. In contrast to many previously published studies, more recent work has been both substantive in size and focused more on true community-based studies with the consequence that estimates of occurrence in risk obtained are likely to reflect more accurately the true nature of any associations observed.