LIMIT-HF: The Effect of Diet and Exercise in Heart Failure

Sponsor

Baylor College of Medicine (Other)

Overall Status

Completed

CT.gov ID

NCT00297154

Collaborator

National Center for Research Resources (NCRR) (NIH)

Enrollment

Arms

Duration (Months)

Study Details

Study Description

Brief Summary

A growing number of people in this country are overweight or obese. This is concerning as increasing weight has been shown to increase the risk of developing heart failure. However, there is also research to suggest that in people who already have heart failure, heavier people live longer. So, how does being overweight put a person at risk for heart failure, but once they have heart failure, protect them? There is no clear explanation for this dilemma.

People who are obese commonly have other diseases, such as high blood pressure, high cholesterol, and diabetes, that increase the risk of developing heart disease. It is this group of diseases that is referred to as "The Metabolic Syndrome." People with the metabolic syndrome also have increased levels of inflammation and clotting proteins in their blood stream. Current treatment of the metabolic syndrome involves using medications for cholesterol, blood pressure, and diabetes. Diet and exercise are also commonly recommended.

"Lifestyle intervention programs" are programs that help people lose weight by changing their eating habits and exercise / activity routines. Weight loss and exercise have been shown to lower the risk of developing diabetes and improve diabetes control, improve cholesterol abnormalities, and lower blood pressure. These programs have not previously included heart failure patients, however.

We hypothesize that using a lifestyle intervention program in addition to the usual medications for heart failure will result in improved symptoms of heart failure and control of the metabolic syndrome.

This study will be the first research study to look at the use of diet and exercise in treating heart failure patients who are overweight / obese with "the metabolic syndrome." The study will last 6 months. From this study we hope to learn whether diet and exercise is helpful in treating heart failure patients who are overweight. Specifically, the study will look at the short term effects on cardiac risk factors (blood pressure, cholesterol, blood sugar), heart failure symptoms, and exercise capacity.

Condition or Disease	Intervention/Treatment	Phase
Heart Failure, Congestive Metabolic Syndrome X Obesity	Behavioral: Lifestyle Modification (diet, exercise, and behavior)	N/A

Study Design

Study Type:

Interventional

Actual Enrollment :

20 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

None (Open Label)

Primary Purpose:

Treatment

Official Title:

Lifestyle Modification in the Treatment of Heart Failure

Study Start Date :

Mar 1, 2005

Actual Primary Completion Date :

Jun 1, 2009

Actual Study Completion Date :

Jun 1, 2009

Arms and Interventions

Arm	Intervention/Treatment
No Intervention: Control Patients continue receive a single educational session and continue medical managment of heart failure as per their physician
Experimental: Lifestyle modification Patients recieve weekly sessions with dietician, replace 2 meals/day with meal replacement beverage, and initiate a walking program.	Behavioral: Lifestyle Modification (diet, exercise, and behavior) Patients recieve weekly sessions with dietician, replace 2 meals/day with meal replacement beverage, and initiate a walking program.

Arm

Intervention/Treatment

No Intervention: Control

Patients continue receive a single educational session and continue medical managment of heart failure as per their physician

Experimental: Lifestyle modification

Patients recieve weekly sessions with dietician, replace 2 meals/day with meal replacement beverage, and initiate a walking program.

Behavioral: Lifestyle Modification (diet, exercise, and behavior)

Patients recieve weekly sessions with dietician, replace 2 meals/day with meal replacement beverage, and initiate a walking program.

Outcome Measures

Primary Outcome Measures

Measuring the change in Flow Mediated Dilation (FMD) and flow velocity integral (FVI) to assess endothelial function. [6 months]
Correlating change in vascular reactivity with renin, angiotensin II, and aldosterone levels. [6 months]

Secondary Outcome Measures

Examining the impact of the lifestyle interventions on quality of life as measured by the validated Kansas City Cardiomyopathy Questionnaire. [3 and 6 months]
Assessing the effectiveness of the lifestyle intervention by sequential tracking of the weekly minutes of physical activity and body composition parameters. Overall exercise tolerance will be assessed using the 6 minute walk test. [3 and 6 months]
Defining alterations in metabolic syndrome parameters, inflammatory cytokines and platelet activation. [3 and 6 months]

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 75 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

Must meet 3 or more of the NCEP defined criteria for metabolic syndrome
Waist circumference greater than 40 inches (102 cm) for men and 35 inches ( 88 cm) for women
Serum triglyceride level greater than or equal to 150 mg/dL
HDL level less than 40 mg/dL for men or 50 mg/dL for women
Blood pressure greater than 130/85 or treatment for hypertension
Fasting glucose greater than 110 mg/dL or treatment for diabetes
Individuals with heart failure of ischemic or nonischemic etiologies * NYHA class II - III symptoms
Left ventricular ejection fraction less than 40%
Age 18-75 years
BMI greater than 25 kg/m2
Patients must have undergone a VO2 or exercise stress test within the last 6 months to exclude active ischemia or exercise-induced dysrhythmias

Exclusion Criteria:

NYHA IV or 6 minute walk less than 300 meters
Blood pressure greater than 160/100 mmHg
Patients undergoing active titration of their cardiac medications
Other comorbid illnesses which limit expected lifespan or affect the safety of interventions
Weight loss of more than 10 pounds of non-edematous body weight within the past 3 months
Pregnancy
HIV+, active tuberculosis or hepatitis C
Cancer requiring treatment within the past 5 years, unless the prognosis is excellent
Unstable angina, myocardial infarction, coronary artery bypass surgery, or angioplasty within the last 3 months
Angina with exertion
History of malignant arrythmias (Ventricular Tachycardia / Ventricular Fibrillation) without implanted defibrillator
Valvular heart disease:
Symptomatic aortic or mitral stenosis
Asymptomatic aortic or mitral stenosis that is moderate or greater in severity
Severe mitral regurgitation
Hypertrophic cardiomyopathy
Severe pulmonary hypertension with a pulmonary artery systolic pressure > 60 mmHg -
Aortic aneurysm (>6 cm in diameter)
Factors that may limit adherence to interventions or affect conduct of the trial
Unable or unwilling to given informed consent
Self-report of substance abuse within the past 12 months -
Failure to comply with the run-in dietary intake and exercise period
History of bariatric surgery
Chronic treatment with corticosteroids
Current diagnosis of schizophrenia, other psychotic disorder, or bipolar disorder
Current use of medications for weight loss
Inability to walk two blocks