• Research Review
• Journal Review

Authors: R Simmons, E van Sluijs, W Hardeman, S Sutton, et al.

Reference: BMC Public Health 2010, 10:226 (open access)
http://www.biomedcentral.com/1471-2458/10/226

Reviewer: Carlos Mendoza Montano, PhD, ProCor contributing editor; President, Guatemalan Association for the Prevention of Heart Diseases (APRECOR), Guatemala City, Guatemala

Reviewer comments: Interventions to promote physical activity usually target individuals based on age, sex, current physical activity status, family history of disease, smoking, weight or socio-economic status. Results from previous trials suggest that these interventions work for some individuals but not for others. ProActive is a randomized trial of behavioral intervention to increase physical activity among individuals who are at increased risk of sedentary lifestyles due to their family history of type 2 diabetes. The investigation indicated that predicting who will increase their physical activity is difficult, and that effective interventions may therefore need to be informed by other determinants not measured in this study. These findings led the authors of the study to conclude that further research is needed to improve prediction of change in physical activity, and inform the development and implementation of interventions.

Purpose of study: To identify predictors of change in objectively measured physical activity over 12 months in the ProActive cohort to improve understanding of factors influencing change in physical activity.

Location of study: United Kingdom

Study design: Potential participants were identified via diabetes registers and medical records of family history in 20 general practices. Three hundred sixty-five offspring of people with type 2 diabetes underwent measurement of physical activity energy expenditure (PAEE) using heart rate monitoring, fitness, and anthropometric and biochemical status at baseline and 1 year. Linear regression was used to quantify the associations between baseline demographic, clinical, psychosocial and behavioral variables and change in PAEE over 12 months.

Results: ProActive participants significantly increased their PAEE by 0.6k j/min over one year, the equivalent of around 20 minutes brisk walking/day. Male sex and higher fitness at baseline predicted increase in PAEE. No significant associations were found for any other variables. Very few baseline demographic, clinical, psychosocial and behavioral predictors were associated with change in objectively measured physical activity.

Additional references:
D Laaksonen, J Lindstrom, T Lakka, J Eriksson, et al. Physical activity in the prevention of type 2 diabetes: The Finnish diabetes prevention study. Diabetes 2005, 54(1):158-165. http://diabetes.diabetesjournals.org/content/54/1/158.abstract

E Kahn, L Ramsey, R Brownson, G Heath, et al. The effectiveness of interventions to increase physical activity. A systematic review. Am J Prev Med 2002, 22(4 Suppl):73-107. http://www.ncbi.nlm.nih.gov/pubmed/11985936