To examine the associations of physical activity and cardiorespiratory fitness (hereafter fitness) with incident glaucoma in a prospective observational study.
Physical activity was measured by self-reported leisure-time activities and fitness was measured by maximal treadmill test. Incident glaucoma was defined based on physician-diagnosis. Participants were 9519 men and women between the ages of 40 and 81 years old (mean age 50) who were enrolled in the Aerobics Center Longitudinal Study. Hazard ratios were estimated using Cox proportional hazard regression after adjusting for age, sex, race, examination year, smoking status, heavy alcohol drinking, hypertension, hypercholesterolemia, abnormal electrocardiogram, diabetes, cardiovascular disease, and cancer.
Total 128 cases of incident glaucoma were reported during a mean follow-up of 5.7 years. A significantly lower risk of incident glaucoma (hazard ratio [HR] 0.53, 95% confidence interval [95% CI] 0.35-0.79), was found in individuals who met the physical activity guidelines of ≥500 metabolic equivalent-minutes (MET-min) per week compared to inactive individuals (0 MET-min/week). Compared with low fitness (lower third), individuals with high fitness (upper third) also had a significantly lower risk of incident glaucoma (HR 0.60, 95% CI 0.38-0.95). A joint analysis of physical activity and fitness showed that meeting physical activity guidelines and being in the high fitness category was associated with the lowest risk for developing glaucoma (HR 0.49, 95% CI 0.31-0.79).
These data provide epidemiological evidence that meeting physical activity guidelines or being fit reduces the risk of developing glaucoma.
1Iowa State University, College of Human Sciences, Department of Kinesiology, Ames, IA
2University of South Carolina, Arnold School of Public Health, Department of Exercise Science, Columbia, SC
Correspondence: Dr. Duck-chul Lee, Iowa State University, 103H Forker Building, Ames, IA 50011, Phone: (515) 294-8042, Fax: (515) 294-8740, email: email@example.com
This study was supported by the National Institutes of Health grants (AG06945, HL62508, DK088195, and HL133069). Steven N. Blair has received unrestricted research grants from The Coca-Cola Company, but the grants were not used to support this manuscript. Other authors declare no conflicts of interest. The results of the study are presented clearly, honestly, and without fabrication, falsification, or inappropriate data manipulation. The authors have no conflicts of interest. The results of the present study do not constitute endorsement by the American College of Sports Medicine.
Accepted for Publication: 12 June 2018