Association of Accelerometer-Measured Physical Activity With Leukocyte Telomere Length Among Older Women.
BACKGROUND
Previous studies on physical activity and telomere length have relied largely upon self-reported physical activity data, and few studies have examined older adults. The association of objectively measured physical activity with leukocyte telomere length (LTL) is currently unknown.


METHODS
In this study, we examined cross-sectional associations between accelerometer-measured total, light, and moderate-to-vigorous physical activity (MVPA) and LTL, measured using Southern blot. The sample included 1,405 older (64-95 years old) white and African American women from the Women's Health Initiative. Multiple linear regression models adjusting for potential confounders were used to determine the association between accelerometer-measured physical activity and LTL.


RESULTS
Overall, the mean (standard deviation) of total, light, and moderate-to-vigorous activity was 5.5 (1.6), 4.7 (1.3), and 0.8 (0.5) h/d, respectively. Adjusting for accelerometer wear time, age, race/ethnicity, education, marital status, smoking, alcohol, body mass index, a history of chronic diseases, and hormone therapy use, LTL was 80 (95% confidence interval: 9, 150) base pairs longer among women with ≥2.5 compared with <2.5 h/wk of MVPA. Light activity was not significantly associated with LTL. For total activity, the most physically active women had significantly longer LTL than the least active women after adjustment for demographic and lifestyle characteristics; however, findings were not significant after further adjustment for health-related factors.


CONCLUSIONS
Older women meeting current recommendations of ≥2.5 h/wk of MVPA, as assessed by accelerometer, had longer LTL. Additional studies using accelerometers in large, diverse cohorts of older women are needed to confirm and extend these findings.
Division of Epidemiology, Department of Family Medicine and Public Health, University of California, San Diego School of Medicine, La Jolla.
Aladdin H
AH
Shadyab
Department of Epidemiology and Environmental Health, University at Buffalo, New York.
Michael J
MJ
LaMonte
Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington.
Charles
C
Kooperberg
Department of Epidemiology, University of Washington, Seattle.
Alexander P
AP
Reiner
Division of Biostatistics and Study Methodology, Center for Translational Science, George Washington University and Children's National Medical Center, District of Columbia.
Cara L
CL
Carty
Department of Aging and Geriatric Research, Institute on Aging, University of Florida, Gainesville.
Todd M
TM
Manini
Department of Preventive Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
Lifang
L
Hou
Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington.
Chongzhi
C
Di
Division of Epidemiology, Department of Family Medicine and Public Health, University of California, San Diego School of Medicine, La Jolla.
Andrea Z
AZ
LaCroix
D061725:Accelerometry / Q000379:methods*; D001741:Black or African American; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000208:ethnology / Q000235:genetics*; D015139:Blotting, Southern; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007962:Leukocytes; D008875:Middle Aged; D016615:Telomere / Q000235:genetics*; D014481:United States / Q000453:epidemiology; D044465:White People
Biomarker; Longevity; MVPA; Minority aging; Postmenopausal