Copenhagen study of overweight patients with coronary artery disease undergoing low energy diet or interval training: the randomized CUT-IT trial protocol

Abstract

BackgroundCoronary artery disease (CAD) is accountable for more than 7 million deaths each year according to the World Health Organization (WHO). In a European population 80% of patients diagnosed with CAD are overweight and 31% are obese. Physical inactivity and overweight are major risk factors in CAD, thus central strategies in secondary prevention are increased physical activity and weight loss.Methods/DesignIn a randomized controlled trial 70 participants with stable CAD, age 45–75, body mass index 28–40 kg/m2 and no diabetes are randomized (1:1) to 12 weeks of intensive exercise or weight loss both succeeded by a 40-week follow-up. The exercise protocol consist of supervised aerobic interval training (AIT) at 85-90% of VO2peak 3 times weekly for 12 weeks followed by supervised AIT twice weekly for 40 weeks. In the weight loss arm dieticians instruct the participants in a low energy diet (800–1000 kcal/day) for 12 weeks, followed by 40 weeks of weight maintenance combined with supervised AIT twice weekly. The primary endpoint of the study is change in coronary flow reserve after the first 12 weeks’ intervention. Secondary endpoints include cardiovascular, metabolic, inflammatory and anthropometric measures.DiscussionThe study will compare the short and long-term effects of a protocol consisting of AIT alone or a rapid weight loss followed by AIT. Additionally, it will provide new insight in mechanisms behind the benefits of exercise and weight loss. We wish to contribute to the creation of effective secondary prevention and sustainable rehabilitation strategies in the large population of overweight and obese patients diagnosed with CAD.Trial registrationClinicalTrials.gov: NCT01724567

A randomized trial comparing the effect of weight loss and exercise training on insulin sensitivity and glucose metabolism in coronary artery disease

“…In the present study an interventional group with concurrent AIT and LED could have addressed this issue; however, we did not consider simultaneous high-intensity AIT and a rapid, shortterm weight loss feasible. Instead, the trial design [13] comprised a 40-week follow-up during which LED participants consulted the dietician once a month to maintain the weight loss as described in Section 2.2. At the same time they underwent AIT twice weekly to evaluate training effects following a considerable weight loss.…”

“…Sample size calculation has been published previously [13] requiring 26 participants in each group. Allowing for a drop-out rate of up to 25%, 70 participants were included.…”

“…As described previously [13] the total duration of the AIT protocol was 38 min. It was initiated by a 10-min warm-up on a staircase or an exercise bike followed by high intensity interval training on an exercise bike.…”

“…Population, design and intervention in this randomized trial were described previously [13]. In short, the main inclusion criteria were CAD diagnosed more than 6 months prior to inclusion, body mass index (BMI) 28-40 m/kg 2 , age 45-75 years and no diabetes.…”

“…The CUT-IT trial was designed to compare the effect of aerobic interval training (AIT) with limited weight loss and a considerable weight loss following a low energy diet (LED) as secondary prevention in CAD [13]. We previously reported that the interventions were feasible and caused the desired improvements in physical fitness and body weight [14].…”