Tuesday, April 21, 2015

Exercise and health‐related quality of life in older long‐term prostate cancer survivors

In a study just published in the journal Cancer -with Dr. Laurien Buffart as first author-, we examined the effects of 12 months of exercise on health-related quality of life (HRQoL) in older long-term survivors of prostate cancer. We also studied for whom this intervention was effective and what possible working mechanisms of the intervention were, i.e. we studied moderators (for whom?) and mediators (how?) of the intervention effects.
In total, 100 men with a mean age of 71.7 years participated in and RCT, and were randomly assigned to 6 months of supervised aerobic and resistance exercise followed by 6 months of a home-based exercise maintenance program (EX group) or printed education material regarding physical activity for 12 months (PA group).
The results show that aerobic and resistance exercise appear to have beneficial effects on HRQoL among older, long-term survivors of prostate cancer. These effects were larger among patients who were married, who started exercising sooner rather than later after diagnosis, and who previously used bisphosphonates. Improvements in lower body functional performance as a result of the exercise intervention mediated the effects on HRQoL.

Sunday, April 19, 2015

Successful behavior change in obesity interventions in adults

Overweight and obesity are among the main determinants of avoidable burden of disease worldwide. many interventions have been developed, tested and implemented to treat obesity. Many of such interventions aim at lifestyle changes -i.e. better nutrition, more physical activity to help people lose weight and avoid further weight gain. However, relapse is high in lifestyle obesity interventions involving behavior and weight change. Identifying mediators of successful outcomes in these interventions is critical to improve effectiveness and to guide approaches to obesity treatment, including resource allocation. In an article that just appeared in the journal BMC Medicine -with Prof. Pedro Teixeira as first author, and as part of the larger European Commission-funded Spotlight project-, we reviewed the most consistent self-regulation mediators of medium- and long-term weight control, physical activity, and dietary intake in clinical and community behavior change interventions targeting overweight/obese adults. Using a systematic review methodology we reviewed thirty-five studies testing 42 possible mediators of intervention effect. The results indicate that important prerequisites for medium-/long-term weight control were higher levels of autonomous motivation, self-efficacy/barriers, self-regulation skills (such as self-monitoring), flexible eating restraint, and positive body image. For physical activity, significant mediators were high autonomous motivation, self-efficacy, and use of self-regulation skills. For dietary intake, the evidence was much less clear, and no consistent mediators were identified. We conclude that despite limited evidence, higher autonomous motivation, self-efficacy, and self-regulation skills emerged as the best predictors of beneficial weight and physical activity outcomes; for weight control, positive body image and flexible eating restraint may additionally improve outcomes. These variables represent possible targets for future lifestyle interventions in overweight/obese populations.