Tinker Ready
Oct 02, 2013
Full Story: http://www.medscape.com/viewarticle/812024
Exercise may be just as effective as many drugs in lowering risk for death in the secondary prevention of coronary heart disease, rehabilitation after stroke, and prevention of diabetes, according to an analysis of randomized controlled trials published online October 1 in the British Medical Journal.
Although the researchers note that they were able to find a limited number of randomized controlled trials of exercise, their analysis of combined trial data found no detectable differences in death rates between exercise and drug interventions in the secondary prevention in coronary heart disease and in prediabetes. For stroke patients, the findings suggest that physical activity is more effective at preventing death than drug treatments, including anticoagulants and antiplatelets. However, diuretics appear more effective than exercise in preventing death in cases of heart failure.
The research was conducted by Huseyin Naci, MHS, from the London School of Economics and Political Science in the United Kingdom and the Drug Policy Research Group, Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts, and John P.A. Ioannidis, MD, from the Stanford Prevention Research Center, Stanford University School of Medicine in California.
The researchers looked at 16 meta-analyses including research that combines data from multiple research studies. Four of the studies looked at exercise and 12 measured the effect of drug treatment. The researchers added 3 new exercise trials for a review that included 305 randomized controlled trials with 339,274 participants. For the 4 conditions with evidence on the effectiveness of exercise on mortality, 14,716 participants were included in 57 trials.
The authors note that the lack of exercise trials is a limitation of their study.
“Evidence from randomized controlled trials on the mortality benefits of exercise is scarce,” they write. “Even in treatment areas where such evidence exists, exercise trials evaluating mortality outcomes were at a disadvantage in two ways: considerably fewer trials evaluated exercise than drugs…and fewer people participated in exercise trials.”
For example, although there is much evidence that drugs such as simvastatin lower death rates in the secondary prevention of cardiovascular disease, research on the mortality benefits of exercise is limited, they write. In addition, evidence on how physical activity compares with drug interventions “is lacking.”
Their analysis found that in coronary heart disease, the odds of mortality was reduced with use of statins (odds ratio [OR], 0.82; 95% credible interval [Crl], 0.75 – 0.90), β blockers (OR, 0.85; 95% Crl, 0.78 – 0.92), angiotensin-converting enzyme inhibitors (OR, 0.83; 95% Crl, 0.72 – 0.96), and antiplatelets (OR, 0.83; 95% Crl,0.74 – 0.93) compared with controls. Exercise produced similar results, but with wider credible intervals (OR, 0.89, 95% Crl, 0.76 – 1.04).
Exercise was more effective than any drug intervention in reducing the death rate among patients with stroke (OR, 0.09; 95% Crl, 0.01 – 0.72). However, the researchers note “considerable uncertainty” in that finding because of the small number of events in exercise trials.
Neither exercise nor drugs were clearly effective in reducing death rates in prediabetes, the authors found. In heart failure, fewer deaths occurred with diuretics (OR, 0.19; 95% Crl, 0.03 – 0.66) and β blockers (OR, 0.71; 95% Crl, 0.61 – 0.80) compared with controls. Diuretics were more effective than exercise (OR, 0.24; 95% Crl, 0.04 – 0.85), angiotensin-converting enzyme inhibitors (OR, 0.21; 95% Crl, 0.03 – 0.76), β blockers (OR, 0.27; 95% Crl, 0.04 – 0.93), and angiotensin receptor blockers (OR, 0.21; 95% Crl, 0.03 – 0.73).
“Given the scarcity of financial resources to fund future trials of exercise interventions, one option would be to require such evidence from pharmaceutical companies,” the authors write. “In cases where drug options provide only modest benefit, patients deserve to understand the relative impact that physical activity might have on their condition.”
The authors have disclosed no relevant financial relationships.
BMJ. Published online October 2, 2013. Full text