Total mortality after changes in leisure time physical activity in 50 year old men: 35 year follow-up of population based cohortBMJ 2009; 338 doi: http://dx.doi.org/10.1136/bmj.b688 (Published 06 March 2009) Cite this as: BMJ 2009;338:b688
- Liisa Byberg, researcher 1,
- Håkan Melhus, professor 2,
- Rolf Gedeborg, researcher 3,
- Johan Sundström, researcher 4,
- Anders Ahlbom, professor 5,
- Björn Zethelius, researcher 6,
- Lars G Berglund, statistician 7,
- Alicja Wolk, professor 8,
- Karl Michaëlsson, senior lecturer 1
- 1Department of Surgical Sciences, Section of Orthopaedics, and Uppsala Clinical Research Centre, Uppsala University, SE-75185 Uppsala, Sweden
- 2Department of Medical Sciences, Section of Clinical Pharmacology, Uppsala University, Uppsala
- 3Department of Surgical Sciences, Section of Anaesthesiology and Intensive Care, and Uppsala Clinical Research Centre, Uppsala University, Uppsala
- 4Department of Medical Sciences, Section of Acute and Internal Medicine, Uppsala University, Uppsala
- 5Department of Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, SE-17177 Stockholm, Sweden
- 6Department of Public Health and Caring Sciences, Section of Geriatrics, Uppsala University, Uppsala
- 7Uppsala Clinical Research Centre, Uppsala University, Uppsala
- 8Department of Nutritional Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm
- Correspondence to: L Byberg
- Accepted 16 December 2008
Objective To examine how change in level of physical activity after middle age influences mortality and to compare it with the effect of smoking cessation.
Design Population based cohort study with follow-up over 35 years.
Setting Municipality of Uppsala, Sweden.
Participants 2205 men aged 50 in 1970-3 who were re-examined at ages 60, 70, 77, and 82 years.
Main outcome measure Total (all cause) mortality.
Results The absolute mortality rate was 27.1, 23.6, and 18.4 per 1000 person years in the groups with low, medium, and high physical activity, respectively. The relative rate reduction attributable to high physical activity was 32% for low and 22% for medium physical activity. Men who increased their physical activity level between the ages of 50 and 60 continued to have a higher mortality rate during the first five years of follow-up (adjusted hazard ratio 2.64, 95% confidence interval 1.32 to 5.27, compared with unchanged high physical activity). After 10 years of follow-up their increased physical activity was associated with reduced mortality to the level of men with unchanged high physical activity (1.10, 0.87 to 1.38). The reduction in mortality associated with increased physical activity (0.51, 0.26 to 0.97, compared with unchanged low physical activity) was similar to that associated with smoking cessation (0.64, 0.53 to 0.78, compared with continued smoking).
Conclusions Increased physical activity in middle age is eventually followed by a reduction in mortality to the same level as seen among men with constantly high physical activity. This reduction is comparable with that associated with smoking cessation.
Contributors: LB and KM designed the study, analysed and interpreted the data, wrote the manuscript, and are guarantors. HM contributed to the study design, interpretation of the data, and writing of the manuscript. LGB provided statistical advice, analysed and interpreted the data, and commented on drafts of the manuscript. RG and AA interpreted the data and made significant contributions to drafts of the manuscript. JS, BZ, and AW provided clinical and methodological advice and commented on drafts of the manuscript. All authors declare that they accept full responsibility for the conduct of the study, had access to the data, and controlled the decision to publish.
Funding: The study was funded by the Swedish Research Council. The funder had no role in the design and conduct of the study; the collection, management, analysis, and interpretation of data; the writing of the manuscript; or the decision to submit the manuscript for publication.
Competing interests: None declared.
Ethical approval: The study was approved by the ethics committee at the Faculty of Medicine, Uppsala University, Sweden, and all participants gave written informed consent.
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