2. Introduction
Physical activity (PA) and increased physical fitness are
known to decrease the likelihood of morbidity and mortality
from a variety of causes. Some examples of are CVD,
insulin resistance and hypertension. An increase in
physical activity also concomitantly increases longevity.
3. What are telomeres?
Telomeres are specialized nucleoprotein structures that
protect chromosomal ends from degradation. They
progressively shorten during cellular division and can
signal replicative senescence below a critical length.
Length is predominantly maintained by telomerase
4. More telomere info
● Telomere length is a primary biomarker of cellular aging, that has been recently associated with
CVD, insulin resistance, hypertension and morbidity and mortality.
● Telomeres are found on the ends of linear chromosomes and act as a mitotic clock, which
shortens with every cell division until cellular senescence is reached.
● Telomeres are considered an important aging marker.
5. More telomere info
● Telomeres and their length are dynamic. Length and activity has been shown to be influenced
by oxidative and psychological stress, as well as PA.
● In certain cells, the ribonucleoprotein, telomerase, maintains and lengthens telomeres. This
allows continued mitotic activity without progression to senescence.
● In cells with telomerase activity, cellular aging is delayed.
6. Goals
The purpose of this study was to explore the relationship between PA levels
with telomere and telomerase activity in the immune cells of older men and
women. The association of the hTERT (human telomere reverse transcriptase)
genotype with telomere length and telomerase enzyme activity was also
investigated.
7. Hypothesis
The hypothesis was that greater PA levels would be associated with longer
telomere lengths and that individuals with the hTERT TT genotype would have
longer telomere length and greater telomerase enzyme activity compared with
the hTERT cc genotype carriers.
The hTERT gene that encodes for catalytically active subunit of telomerase is
known to have a single nucleotide polymorphism (SNP) in the promoter region.
The T allele of the SNP affects the promoter activity of the TERT gene and has
been associated with greater telomere length and greater telomerase activity
when compared to the C allele of this SNP.
8. Subjects
Seventy males and females aged 50-70 years were
recruited through newspaper ads, flyers and word of
mouth.
One subject was excluded due to inconsistent PA
responses, reducing sample size to 69 participants.
Potential volunteers were excluded if they any underlying medical conditions. All subjects were
healthy, according to their responses to a medical health questionnaire.
9. Procedures
All subjects completed both a medical health
history questionnaire and the Yale Physical
Activity Survey (YPAS).
Information extracted from medical health
history included:
10. Procedures -cont-
DOB
Self-reported race and ethnicity
Current medications
Past and present medical disorders
Self-reported PA consistency throughout the past decades
Family history of age-related mental decline
Anthropometric measures included height, weight, and BMI and were
collected using standard measures.
11. Methods
The participants were assessed for weekly EEE (exercise
energy expenditure) using the YPAS.
Lifetime consistency of EEE was also determined.
Relative telomere length and telomerase activity were
measured in peripheral blood mononuclear cells
(PBMC).
12. Results
● Significant differences were observed among all groups
for EEE
● Of the seventy recruited subjects, one was excluded on
the basis of the physical activity inclusion criteria
13. Results
● The second EEE quartile showed significantly
longer telomere lengths than both the first
and fourth EEE quartiles but was not
significantly different than the third EEE
quartile
15. Results
● The TT genotype had the greatest
telomerase enzyme activity and was
significantly different from both the CT
and CC genotype groups
16. Results
● A significant interaction was observed for telomerase
enzyme activity such that the TT genotype/fourth EEE
quartile had significantly greater telomerase activity than
all other groups
17. Conclusion
There was a significant relationship between physical activity level and telomere length, such that moderate levels of physical
activity are associated with a significantly longer PBMC telomere length compared with the lowest and highest quartiles of
physical activity
The results for moderate physical activity levels are consistent with previous findings showing a positive dose-response
relationship between leisure time physical activity and telomere length
No relationship was observed between physical activity level and telomerase enzyme activity in PBMC
They observed a significant association between hTERT TT genotype and telomerase enzyme activity and a preliminary
evidence for an interaction between hTERT genotype and physical activity level that deserves further exploration
18. Conclusion
Physical activity level over the past five years or longer was significantly associated with telomere length
Acute exercise or short-term physical activity alone may not be a strong enough stimulus to cause short-term changes to
telomere length but a protective effect may be manifested for five years or more of a consistent physical activity
The findings showing an association between EEE and PBMC telomere length agree with current literature on exercise
training and immune function . A moderate level of endurance exercise training has been shown to elicit an enhanced
immune response and reduced infection risk compared with both low (e.g., sedentary) and high (e.g., overtraining)
exercise training levels
Shorter telomere length is associated with both low and high levels of physical activity
This study did not observe a significant relationship between telomerase enzyme activity and physical activity; however, in
previous studies of mild to strenuous exercise in lab rats did not significantly change telomerase enzyme activity
19. In summary...
It was confirmed that moderate physical activity may be beneficial to telomere length in PBMC but show that higher physical
activity levels may not have such a positive relationship
20. References
Chilton, W.L., Marques, F.Z., West, J., Kannourakis, G., Berzins, S.P., O’Brien, B.J., Charchar, F.J. US National Library of
Medicine. Acute Exercise Leads to Regulation of Telomere- Associated Genes and MicroRNA Expression in Immune Cells, 2014.
Web May 8, 2015.
Ludlow, A.T., Zimmerman, J.B., Witkowski, S., Hearn, J.W., Hatfield, B.D., and Roth, S.M. Med Sci Sports Exercise. Relationship
between Physical Activity Level, Telomere Length, and Telomerase Activity, 2008. Web May 10, 2015.
