The effects of a lifestyle intervention on leisure-time sedentary behaviors in adults at risk: The Hoorn Prevention Study, a randomized controlled trial

Highlights

• We examined the effects of a lifestyle intervention on sedentary behaviors.

• At short and long term, no relevant between-group differences were seen.

• It is currently not advised to implement this type of lifestyle programs.

Abstract

Objective

This study set out to assess the short- and long-term effects of a primary care-based lifestyle intervention on different domains of leisure-time sedentary behaviors in Dutch adults at risk of type 2 diabetes and cardiovascular diseases.

Methods

Between 2007 and 2009, adults (n = 622) at risk were randomly assigned to a counseling intervention aimed at adopting healthy lifestyle behaviors, or a control group that only received health brochures. Follow-up measures were done after 6, 12 and 24 months. Linear regression analysis was used to examine between-group differences in self-report minutes per day sedentary behaviors, adjusted for baseline values. Stratified analyses were performed for sex and educational attainment.

Results

Seventy-nine percent (n = 490) of participants completed the last follow-up. Mean baseline sedentary behaviors were 254.6 min per day (SD = 136.2). Intention-to-treat analyses showed no significant differences in overall or domain-specific sedentary behaviors between the two groups at follow-up. Stratified analyses for educational attainment revealed a small and temporary between-group difference in favor of the intervention group, in those who finished secondary school.

Conclusions

A primary care-based general lifestyle intervention was not more effective in reducing leisure-time sedentary behaviors than providing brochures in adults at risk for chronic diseases.

Introduction

Sedentary behavior has recently been identified as public health problem. Sedentary behavior, which is distinctly different from physical inactivity, is defined as activities that are done sitting or in reclining posture that expend less than 1.5 times the basal metabolic rate (Sedentary Behaviour Research Network, 2012). Previous large population-based studies showed that high levels of sedentary behavior (such as prolonged television viewing or sitting in a car) are associated with increased risk of having metabolic syndrome (Edwardson et al., 2012), type 2 diabetes (T2DM; Grontved and Hu, 2011, van Uffelen et al., 2010, Wilmot et al., 2012), cardiovascular diseases (CVD; Grontved and Hu, 2011, Wilmot et al., 2012) and mortality (Dunstan et al., 2009, Grontved and Hu, 2011, van Uffelen et al., 2010, Wijndaele et al., 2010, Wilmot et al., 2012), independent of physical activity.

Sedentary behaviors are increasingly prevalent in modern society. The number of sedentary jobs has been steadily increasing over the past 50 years (Church et al., 2011), as has time spent in inactive transport modes (Brownson et al., 2005), watching TV (Brownson et al., 2005) and using a computer (Chau et al., 2012). A recent study showed that in 2006, Australian adults spent 90% of leisure time sedentary (Chau et al., 2012), and 53% of that time was spent on screen-based activities (i.e., watching TV and using the computer).

Although sedentary behavior research has expanded rapidly over the past decade, studies that evaluate interventions influencing sedentary behaviors are scarce, especially for adults (Owen et al., 2011). Little is known about how best to change sedentary behavior in this age group, as nearly all of the intervention work has been with young people and sedentary screen time (Wilmot et al., 2012). It has been suggested that future diabetes prevention programs should consider promoting reduced sedentary behavior alongside more traditional lifestyle behaviors such as physical activity and diet (Wilmot et al., 2012), and one suggested approach is to examine sedentary behavior change following interventions to increase physical activity (Owen et al., 2011).

We developed and implemented a feasible lifestyle intervention for the primary prevention of T2DM and CVD, tailored to the available resources and infrastructure for national primary health care services in the Netherlands. The intervention consisted of a cognitive behavior program, based on the theory of planned behavior (TPB) and the theory of self-regulation, and was performed in a primary health care setting. A key element of this trial was that the participants were supported in their motivation and self-empowerment to make sustainable changes in lifestyle behaviors by means of a combination of practical, evidence-based tools. The intervention targeted adults at risk for T2DM and CVD and focused especially on physical activity, dietary behavior and smoking (Lakerveld et al., 2008). The effects of the intervention on these specific lifestyle behaviors, disease risk and on its cost-effectiveness are published elsewhere (Lakerveld et al., 2013, van Wier et al., 2013). The interventions' overall aim was to increase awareness and motivation to adopt a healthier lifestyle, which included getting participants “out of their chair” to reduce their risk for chronic diseases. Targeting this high-risk group may particularly be meaningful, as a recent longitudinal study showed that shorter sitting times and sufficient physical activity are independently protective against all-cause mortality not just for healthy individuals but also for those with T2DM and CVD risk (van der Ploeg et al., 2012).

The aims of this study are to evaluate the effects of the lifestyle intervention on typical domains of leisure-time sedentary behaviors including TV viewing, computer use and reading in adults at risk of developing T2DM and CVD.