Christine M Friedenreich1, Qinggang Wang2, Nicholas S Ting3, Darren R Brenner4, Shannon M Conroy5, John B McIntyre6, Alexis Mickle2, Kerry S Courneya7, Tara Beattie8. 1. Department of Cancer Epidemiology and Prevention Research, CancerControl Alberta, Alberta Health Services, Calgary, Alberta, Canada; Department of Oncology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada. Electronic address: christine.friedenreich@albertahealthservices.ca. 2. Department of Cancer Epidemiology and Prevention Research, CancerControl Alberta, Alberta Health Services, Calgary, Alberta, Canada. 3. Department of Molecular Biology and Biochemistry, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada. 4. Department of Cancer Epidemiology and Prevention Research, CancerControl Alberta, Alberta Health Services, Calgary, Alberta, Canada; Department of Oncology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada. 5. Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA. 6. Translational Laboratory, Tom Baker Cancer Center, CancerControl Alberta, Alberta Health Services, Calgary, Alberta, Canada. 7. Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada. 8. Department of Oncology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; Department of Molecular Biology and Biochemistry, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
Abstract
BACKGROUND: Short telomeres may indicate a higher risk of cancer and other chronic diseases. Some observational studies show positive associations between leukocyte telomere length (LTL) and physical activity levels. We hypothesized, therefore, that exercise may be one strategy for slowing telomere attrition. METHODS: We conducted an ancillary analysis of blood from a year-long, two-centred, two-armed (1:1) randomized controlled trial of aerobic exercise versus usual inactivity. The analysis included 212 physically inactive, disease-free, non-smoking, postmenopausal women (n = 99 exercisers, n = 113 controls) in Alberta, Canada (2003-2006). The exercise prescription was aerobic exercise five days/week (supervised three days/week), 45 min/session, achieving 70-80% heart rate reserve. Baseline and 12-month LTL were analyzed using quantitative real-time polymerase chain reactions (qPCR). The primary statistical analysis was intention-to-treat, comparing the ratio of mean LTLs (12-months:baseline) for exercisers versus controls from a general linear model. Secondary analyses included a per-protocol analysis (≥90% adherence) and analyses stratified by baseline LTL, age, body mass index, and fitness level, respectively. RESULTS:Participants were overweight at baseline (mean BMI = 29 kg/m2). The primary analysis showed no evidence that LTL change differed between groups (12-month mean LTL change for the exercise group: -13% (95% CI: -32%, 11%) versus controls: -8% (95%CI: -27%, 15%); treatment effect ratio (TER, Exercise/Control) = 0.95 (95% CI: 0.68, 1.32). Per-protocol results were similar (TER = 0.87, 95% CI: 0.59, 1.30). In stratified models, TERs ranged from 0.68 to 1.35 across strata and P-interaction > 0.05). CONCLUSION: We found no evidence to suggest that one year of aerobic exercise alters telomere attrition significantly in healthy postmenopausal women.
RCT Entities:
BACKGROUND: Short telomeres may indicate a higher risk of cancer and other chronic diseases. Some observational studies show positive associations between leukocyte telomere length (LTL) and physical activity levels. We hypothesized, therefore, that exercise may be one strategy for slowing telomere attrition. METHODS: We conducted an ancillary analysis of blood from a year-long, two-centred, two-armed (1:1) randomized controlled trial of aerobic exercise versus usual inactivity. The analysis included 212 physically inactive, disease-free, non-smoking, postmenopausal women (n = 99 exercisers, n = 113 controls) in Alberta, Canada (2003-2006). The exercise prescription was aerobic exercise five days/week (supervised three days/week), 45 min/session, achieving 70-80% heart rate reserve. Baseline and 12-month LTL were analyzed using quantitative real-time polymerase chain reactions (qPCR). The primary statistical analysis was intention-to-treat, comparing the ratio of mean LTLs (12-months:baseline) for exercisers versus controls from a general linear model. Secondary analyses included a per-protocol analysis (≥90% adherence) and analyses stratified by baseline LTL, age, body mass index, and fitness level, respectively. RESULTS:Participants were overweight at baseline (mean BMI = 29 kg/m2). The primary analysis showed no evidence that LTL change differed between groups (12-month mean LTL change for the exercise group: -13% (95% CI: -32%, 11%) versus controls: -8% (95%CI: -27%, 15%); treatment effect ratio (TER, Exercise/Control) = 0.95 (95% CI: 0.68, 1.32). Per-protocol results were similar (TER = 0.87, 95% CI: 0.59, 1.30). In stratified models, TERs ranged from 0.68 to 1.35 across strata and P-interaction > 0.05). CONCLUSION: We found no evidence to suggest that one year of aerobic exercise alters telomere attrition significantly in healthy postmenopausal women.
Authors: Niharika A Duggal; Grace Niemiro; Stephen D R Harridge; Richard J Simpson; Janet M Lord Journal: Nat Rev Immunol Date: 2019-09 Impact factor: 53.106
Authors: Rocío Barragán; Carolina Ortega-Azorín; Jose V Sorlí; Eva M Asensio; Oscar Coltell; Marie-Pierre St-Onge; Olga Portolés; Dolores Corella Journal: J Clin Med Date: 2021-12-24 Impact factor: 4.241
Authors: Leandro T Franzoni; Eduardo L Garcia; Stephanie B Motta; Mabel M Ahner; Otávio A Bertoletti; Marco A L Saffi; Anderson D da Silveira; Alexandre A Pereira; Adamastor H Pereira; Luiz C Danzmann; Ricardo Stein Journal: Trials Date: 2022-04-11 Impact factor: 2.279
Authors: Juan Luis Sánchez-González; Juan Luis Sánchez-Rodríguez; Raúl Juárez-Vela; Regina Ruiz de Viñaspre-Hernandez; Rogelio González-Sarmiento; Francisco Javier Martin-Vallejo Journal: J Clin Med Date: 2022-03-21 Impact factor: 4.241