A 3-year worksite-based lifestyle intervention to reduce cardiovascular disease risk factors in office employees: Rationale, development and design of two parallel randomized controlled trials

BACKGROUND: Cardiovascular disease (CVD) is a leading cause of death worldwide. With atherosclerosis as underlying cause for many CVD events, prevention or reduction of subclinical atherosclerotic plaque burden (SAPB) can have substantial public health and economic benefits. OBJECTIVE: To present the protocol of a randomized controlled trial (RCT) investigating the (cost)effectiveness of a comprehensive 3-year worksite-based lifestyle intervention program aimed at improving dietary, physical activity, and sedentary behaviours in participants having a high level of SAPB or low level of SAPB compared to standard care. TRIAL DESIGN: Two parallel RCTs nested within the ´Progression of Early Subclinical Atherosclerosis´ (PESA) cohort will be conducted. One RCT (n= 350) will focus on a sample of employees drawn from the cohort with high imaging-defined SAPB and a second RCT (n=650) on a sample with low imaging-defined SAPB. In both RCTs, the participants (aged 40-60) will be randomized into either a group receiving a 3year lifestyle intervention or receiving standard care. The lifestyle intervention primarily aims to improve dietary, physical activity, sedentary behaviours. The intervention consists of three elements: (A) 12 personalized lifestyle counseling sessions over a 30-month period, (B) a wrist worn physical activity tracker, and (C) a sit-stand workstation. Data will be collected at baseline and at 1, 2 and 3-year follow up. Primary outcome measure is a compilation score of blood pressure, physical activity, sedentary time, body weight, diet and smoking (BEWAT). Physical activity and sedentary time will be assessed objectively with the activPAL inclinometer. Questionnaires are used to assess: diet, smoking, sleep habits, depression, perceived stress, job strain, social support, vitality, relaxation, quality of life, health care consumption and intervention processes. Physical measurements include anthropometrics, noninvasive imaging to assess SAPB (using 2D ultrasound of carotids, abdominal aorta and iliofemoral arteries, 3D ultrasound of carotid and femoral arteries and coronary artery calcification by computed tomography), and blood biomarkers. A process evaluation and a cost-effectiveness evaluation will be conducted. DISCUSSION: This study will provide insights into the (cost-) effectiveness of a 3-year worksite lifestyle intervention on CVD risk factors, compared to standard care in participants with high-imaging defined SAPB or low-imaging defined SAPB