Effect of different levels of exercise on telomere length
475
subgroup analysis demonstrated that
longer telomere length was not found
in individuals who engaged in aerobic
exercise (MD 0.07; 95% CI –0.02,
0.17; p = 0.14).
Total search reslut
In addition, longer telomere length
6,763
was positively correlated with exer-
2,651 duplicates removed
cise in both sexes (MD 0.11; 95% CI
4,112 titles
0.02, 0.21; p = 0.02 for males; MD
and abstracts
Common reasons for exclusion:
0.20; 95% CI 0.02, 0.37; p = 0.03 for
screened
-not analyze the association
females). Longer telomere length was
between physical exercise and
telomere lenght
also found in individuals <65 years
71 full texts
-non-English or Chinese study
of age (MD 0.25; 95% CI 0.09, 0.40;
screened
p = 0.002), but not in elderly indivi-
Reasons for exclusion:
duals (MD 0.11; 95% CI –0.09, 0.31;
-cannot provide sufficient data (n=25)
p = 0. 27). Subgroup analysis also
-sample number 1<100 (n=10)
11 eligible
-conference abstract (n=12)
demonstrated a positive relationship
papers
-review (n=13)
in all tissue sources and study types.
Fig. 1. Search results and study selection.
However, longer telomere length was
not significant in active people of
Included studies
European descent (MD 0.07; 95% CI
–0.01, 0.16; p = 0.09), or in the PCR group (MD 0.12;
The characteristics of the included studies, invol-
95% CI –0.01, 0.25; p = 0.07).
ving 19,292 participants, are summarized in Table
I. Telomere length in these studies was
determined using quantitative polyme-
rase chain reaction (q-PCR), telomere
restriction fragment (TRF) methodology,
and Southern blot using leukocytes and
peripheral blood mononuclear cells.
Quality evaluation revealed that one
study achieved the maximum score of 9,
while the score for the remainder of the
studies was > 7. The definition of mode-
rate and robust physical exercise in the
included studies varied. The intensity of
robust exercise was defined as > 2.5 me-
tabolic equivalent tasks (MET) h/week,
while the definition of moderate exercise
Fig. 2. Meta-analysis of the association between telomere length and exercise. 95% CI:
95% confidence interval; SD: standard deviation.
ranged from 1 to 22.5 MET h/week.
Embase
3,923
CINAHL
(EBSCO)
134
SPORDiscus
(EBSCD)
49
Ovid
(medline)
2,629
Other source
28
Pooled results
Active individuals were significantly
associated with longer telomere length,
with a mean difference (MD) of 0.15;
95% CI 0.05, 0.24; I 2 = 99%)(Fig. 2).
Analysis also revealed that both robust
and moderate exercise could significantly
increase telomere length (MD 0.08; 95%
CI 0.04, 0.12; I 2 = 99% (Fig. 3) and MD
0.07; 95% CI 0.03, 0.11; I 2 = 100% (Fig.
4), respectively. Details of the subgroup
analysis are summarized in Table SI. The
Fig. 3. Meta-analysis of the association between telomere length and robust exercise.
95% CI: 95% confidence interval; SD: standard deviation.
J Rehabil Med 51, 2019