Physical exercise is beneficial to everyone, with or without diabetes. But how much actual benefit accrues from it? A recent paper measured the association between physical activity and mortality in diabetes.
In people with diabetes, does physical activity reduce the risk of premature death?
This paper reports the findings of a long-term prospective cohort study and a review of other observational studies.
In the cohort study, 5,859 patients with diabetes were followed to measure how much physical activity they did and what their risk of mortality was. When the researchers stratified the participants into different categories of activity levels, they found that people who undertook moderate levels of physical activity had a 38% (95% CI 22 to 51%) relative risk reduction of overall mortality compared with people who did no exercise at all.
The researchers concluded:
These findings provide empirical evidence supporting the widely shared view that persons with diabetes should engage in regular physical activity.
This result was consistent with the findings of their meta-analysis.
- This review focuses on observational evidence and cannot establish direct causation. However, as it would be unethical to investigate physical activity experimentally in this context, this is probably the best type of evidence we are likely to find.
- Did the meta-analysis employ a rigorous literature search for high-quality studies?
- It is not clear what proportion of the patients had type 1 and type 2 diabetes, and what differences there were between them.
- There may be important differences between the populations, definitions and types of physical exercise, and outcomes of each individual study so the overall results should be viewed with caution. Your population may be different. Is the benefit likely to be the same for people at higher baseline risk of death for example?
- It would be worth looking at the breakdown of these results by different activity levels to see if there is a “dose-response” effect.
- Are any harms reported?
Sluik D, Buijsse B, Muckelbauer R, Kaaks R, Teucher B, Johnsen NF, Tjønneland A, Overvad K, Ostergaard JN, Amiano P, Ardanaz E, Bendinelli B, Pala V, Tumino R, Ricceri F, Mattiello A, Spijkerman AM, Monninkhof EM, May AM, Franks PW, Nilsson PM, Wennberg P, Rolandsson O, Fagherazzi G, Boutron-Ruault MC, Clavel-Chapelon F, Castaño JM, Gallo V, Boeing H, Nöthlings U. Physical Activity and Mortality in Individuals With Diabetes Mellitus: A Prospective Study and Meta-analysis. Arch Intern Med. 2012 Aug 6:1-11. doi: 10.1001/archinternmed.2012.3130. [Epub ahead of print]