Copenhagen Study of Obese Patients With Ischemic Heart Disease Undergoing Low Energy Diet or Interval Training

Eva Prescott70 enrolled

Overview

The purpose of the study is to make a head-to-head comparison of weight loss and interval training as methods of secondary prevention in overweight patients with ischemic heart disease.

In western countries 80 % of patients with ischemic heart disease (IHD) are overweight (BMI \> 25). Weight loss using a low energy diet (LED, 800 - 1000 kcal/day) has been shown to induce a considerable weight loss in obese but otherwise healthy patients and to reduce the risk of cardiovascular disease and diabetes in these subjects. Additionally, a British study using a very low energy diet (VLED, 600 kcal/day) to obtain weight loss, has shown that subject with diagnosed type 2 diabetes had their blood glucose normalized after an 8 week VLED. However, the effect of LED has never been examined in overweight patients with IHD. Several studies have shown that patients with IHD have a beneficial effect of exercise training regarding mortality and reduction in cardiovascular risk factors. A Norwegian group has shown that aerobic interval training results in the biggest increase in maximal oxygen uptake (VO2max). A high VO2max is correlated to decreased mortality in patients with IHD. In conclusion, weight loss and exercise are known strategies in preventing progression of IHD and development of type 2 diabetes in these patients, however a head-to-head comparison of the two methods has never been made and it is unknown which intervention is the most effective in improving cardiovascular risk profile. Furthermore, several mechanisms behind the known beneficial effect of these interventions are unknown.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

SINGLE

Enrollment

Conditions

Ischemic Heart Disease Obesity

Interventions

Interval TrainingOTHER

Interval training (IT) on an exercise bike 3 times a week, for the first 12 weeks, followed by 40 weeks of IT 2 times a week on exercise bike. Each training session consists of active intervals with a total duration of 16 minutes (durations intervals between 1 and 4 minutes) at 90% of maximal heart rate. Active intervals are separated by active pauses at 60% of maximal heart rate.

Weight LossOTHER

Low calorie diet approx. 1000 kcal/day for 8 - 10 weeks to obtain a 10 - 15 % weight loss.

Eligibility

Sex: ALLMin age: 45 YearsMax age: 75 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Stable Ischemic Heart Disease * BMI 28 - 40 kg/m2 Exclusion criteria: * Known Diabetes Mellitus * Repeated Fasting plasma glucose ≥ 7 mmol/L or Hba1c \> 7 % * Severe or moderate valve disease * Main stem stenosis * Severe heart failure, Ejection Fraction \< 35 % * Physical or mental disability which are expected to prevent completion of intervention * Severe Chronic obstructive Pulmonary Disease (COPD) (FEV1 \< 50 % of expected) or asthma * Active cancer * Severe kidney (GFR \< 40 ml/hour) or severe liver disease * Severe ischemia or arrhythmias during exercise test * 2\. or 3. degree atrio-ventricular (AV) block, not protected by pacemaker * Organised training more than 2 times a week prior to inclusion * Significant weight loss or weight gain (\> 5 %)3 month prior to inclusion * Not able to comprehend written and oral informed consent * Hormone treatment

Locations (1)

Bispebjerg Hospital

Copenhagen, Denmark

Outcomes

Primary Outcomes

Change in Coronary Flow Reserve following the diet or training intervention and a maintenance period

Assessed by a non-invasive echocardiographic Doppler measurement