Long distance running and knee osteoarthritis. A prospective study.

BACKGROUND: Prior studies of the relationship of physical activity to osteoarthritis (OA) of the knee have shown mixed results. The objective of this study was to determine if differences in the progression of knee OA in middle- to older-aged runners exist when compared with healthy nonrunners over nearly 2 decades of serial radiographic observation. METHODS: Forty-five long-distance runners and 53 controls with a mean age of 58 (range 50-72) years in 1984 were studied through 2002 with serial knee radiographs. Radiographic scores were two-reader averages for Total Knee Score (TKS) by modified Kellgren & Lawrence methods. TKS progression and the number of knees with severe OA were compared between runners and controls. Multivariate regression analyses were performed to assess the relationship between runner versus control status and radiographic outcomes using age, gender, BMI, education, and initial radiographic and disability scores among covariates. RESULTS: Most subjects showed little initial radiographic OA (6.7% of runners and 0 controls); however, by the end of the study runners did not have more prevalent OA (20 vs 32%, p =0.25) nor more cases of severe OA (2.2% vs 9.4%, p=0.21) than did controls. Regression models found higher initial BMI, initial radiographic damage, and greater time from initial radiograph to be associated with worse radiographic OA at the final assessment; no significant associations were seen with gender, education, previous knee injury, or mean exercise time. CONCLUSIONS: Long-distance running among healthy older individuals was not associated with accelerated radiographic OA. These data raise the possibility that severe OA may not be more common among runners.

Lifestyle risk factors predict disability and death in healthy aging adults.

BACKGROUND: Associations between modifiable health risk factors during middle age with disability and mortality in later life are critical to maximizing longevity while preserving function. Positive health effects of maintenance of normal weight, routine exercise, and nonsmoking are known for the short and intermediate term. We studied the effects of these risk factors into advanced age. METHODS: A cohort of 2327 college alumnae aged 60 years or more was followed annually (1986-2005) by questionnaires addressing health risk factors, history, and Health Assessment Questionnaire disability. Mortality data were ascertained from the National Death Index. Low-, medium-, and high-risk groups were created on the basis of the number (0, 1, ≥2) of health risk factors (overweight, smoking, inactivity) at baseline. Disability and mortality for each group were estimated from unadjusted data and regression analyses. Multivariable survival analyses estimated time to disability or death. RESULTS: The medium- and high-risk groups had higher disability than the low-risk group throughout the study (P<.001). Low-risk subjects had onset of moderate disability delayed 8.3 years compared with high-risk subjects. Mortality rates were higher in the high-risk group (384 vs 247 per 10,000 person-years). Multivariable survival analyses showed the number of risk factors to be associated with cumulative disability and increased mortality. CONCLUSION: Seniors with fewer behavioral risk factors during middle age have lower disability and improved survival. These data document that the associations of lifestyle risk factors on health continue into the ninth decade.

Reduced disability and mortality among aging runners: a 21-year longitudinal study.

BACKGROUND: Exercise has been shown to improve many health outcomes and well-being of people of all ages. Long-term studies in older adults are needed to confirm disability and survival benefits of exercise. METHODS: Annual self-administered questionnaires were sent to 538 members of a nationwide running club and 423 healthy controls from northern California who were 50 years and older beginning in 1984. Data included running and exercise frequency, body mass index, and disability assessed by the Health Assessment Questionnaire Disability Index (HAQ-DI; scored from 0 [no difficulty] to 3 [unable to perform]) through 2005. A total of 284 runners and 156 controls completed the 21-year follow-up. Causes of death through 2003 were ascertained using the National Death Index. Multivariate regression techniques compared groups on disability and mortality. RESULTS: At baseline, runners were younger, leaner, and less likely to smoke compared with controls. The mean (SD) HAQ-DI score was higher for controls than for runners at all time points and increased with age in both groups, but to a lesser degree in runners (0.17 [0.34]) than in controls (0.36 [0.55]) (P < .001). Multivariate analyses showed that runners had a significantly lower risk of an HAQ-DI score of 0.5 (hazard ratio, 0.62; 95% confidence interval, 0.46-0.84). At 19 years, 15% of runners had died compared with 34% of controls. After adjustment for covariates, runners demonstrated a survival benefit (hazard ratio, 0.61; 95% confidence interval, 0.45-0.82). Disability and survival curves continued to diverge between groups after the 21-year follow-up as participants approached their ninth decade of life. CONCLUSION: Vigorous exercise (running) at middle and older ages is associated with reduced disability in later life and a notable survival advantage.