The Effects of Structured Exercise or Lifestyle Behavior Interventions on Long-Term Physical Activity Level and Health Outcomes in Individuals With Type 2 Diabetes: A Systematic Review, Meta-Analysis, and Meta-Regression
Background: Systematically evaluate the effects of structured exercise and behavioral intervention (physical activity [PA] alone/PA + diet) on long-term PA in type 2 diabetes. Methods: Systematic search of 11 databases (inception to March, 2017). Randomized controlled trials investigating structured exercise/behavioral interventions in type 2 diabetes reporting PA outcomes ≥6 months were selected. Results: Among 107,797 citations retrieved, 23 randomized controlled trials (including 18 behavioral programs and 5 structured exercise) met inclusion criteria (n = 9640, 43.6% men, age = 60.0 (4.0) y). All structured exercise trials demonstrated increased objective PA outcomes relative to control (pooling was inappropriate; I2 = 92%). Of 18 behavioral interventions, 10 increased PA significantly, with effect sizes ranging from 0.2 to 6.6 (pooling was inappropriate; I2 = 96%). After removing 1 outlier, the remaining 17 studies significantly improved PA (pooled effect size = 0.34), although smaller compared with structured exercise. After removing the outlier, meta-regression also revealed significant direct relationships between total contacts (r = .50, P < .01) and more face-to-face counseling (r = .75, P < .001) and increased PA. However, long-term changes in PA and HbA1c were not related. Conclusion: Both structured exercise and behavioral interventions increased PA in type 2 diabetes, although effect sizes were larger for supervised exercise. The effectiveness of behavioral programs was improved when delivery included more extensive and face-to-face contact.
Mosalman Haghighi, Mavros, and Fiatarone Singh are with the Faculty of Health Sciences, The University of Sydney, Lidcombe, New South Wales, Australia. Fiatarone Singh is also with Sydney Medical School, The University of Sydney, Camperdown, New South Wales, Australia; Institute for Aging Research, Hebrew SeniorLife, Harvard Medical School, Boston, MA; and Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA.