Prospective study of incident age-related macular degeneration in relation to vigorous physical activity during 7-year follow-up
Paul Thomas Williams 1*
1 Life Sciences Division, Lawrence Berkeley Laboratory, 1 Cyclotron Road
, Berkeley, California, 94720, United States
* To whom correspondence should be addressed. E-mail: ptwilliams{at}lbl.gov.
 |
Abstract |
|---|
Purpose: Test whether the risk of age-related macular degeneration (AMD) decreases with vigorous physical activity.
Design: Prospective study of self-reported clinically diagnosed macular degeneration in male (N=29,532) and female (N=12,176) runners followed prospectively for 7.7 years.
Methods: Survival analyses of incident AMD versus average running distance (km/day), cardiorespiratory fitness (10-km footrace performance), BMI, cigarette use, and diet at baseline.
Results: The 110 men and 42 women reporting incident AMD were older than those unaffected (mean±SE: 54.81±0.97 vs. 44.86±0.06 years), and if male were significantly more likely to have once smoked cigarettes (50.6 vs. 41.2%, P=0.04 when adjusted for age). Age and sex-adjusted AMD risk was greater for men and women who consumed more meat (3.17±0.20 vs, 2.55±0.02 servings/week) and less fruit (9.41±0.70 vs. 10.92±0.05 pieces/week). Men and women reporting incident AMD ran significantly less than those who remained unaffected when adjusted for age and sex (4.57±0.30 vs. 5.34±0.02 km/day, P
0.01). When adjusted for age, sex, diet, and smoking history, the relative risk for AMD decreased 10% per km/day increment in running distance. Moreover, compared to men and women who averaged less than 2 km/day, those averaging 2-4 km/day had 19% lower adjusted risk, and those averaging 
4 km/day had 42-54% lower adjusted AMD risk.
Conclusion: Higher doses of vigorous exercise (running) are associated with lower incident AMD risk independent of weight, cardiorespiratory fitness, and cigarette use. Limitations of the analyses include the select nature of the sample and reliance on self-report of both running history and clinically diagnosed AMD
Key Words:
epidemiology, age-related macular degeneration, Physical activity
