Effects of Weight Loss on Cardio-respiratory Function

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01410487
Recruitment Status : Completed
First Posted : August 5, 2011
Last Update Posted : December 2, 2014
Information provided by (Responsible Party):
New York University School of Medicine

Brief Summary:

Obesity is a medical problem of epidemic proportions and is associated with high mortality. Obesity has significant effects on the cardiovascular system, producing structural cardiovascular changes including myocardial hypertrophy, fatty infiltration, and fibrosis; diastolic and systolic dysfunction; changes in pulmonary artery compliance; and increased aortic stiffness - all of which can lead to heart failure. Indeed, evidence suggests that obesity increases the risk for heart disease independent of other known risk factors such as coronary artery disease, hypertension, diabetes mellitus, and obstructive sleep apnea. Obesity also causes significant changes in pulmonary function, including a decrease in expiratory reserve volume and functional residual capacity and closure of peripheral airways. The exact mechanisms for the development of cardiopulmonary disease are not well understood - the pathophysiology is complex and likely multifactorial, related to altered hemodynamic load, altered metabolic activity, underlying inflammation, and increased cardiac output.

Newer diagnostic modalities available at our institution such as cardiac MRI and pulmonary function tests with impulse oscillometry allow us to better evaluate cardiopulmonary dysfunction in patients with severe obesity. Cardiac MRI is especially promising as a non-invasive imaging modality in obese individuals, providing more reproducible measurements of cardiac and vascular anatomy and function relative to echocardiography. Similarly, pulmonary function testing with impulse oscillometry is more sensitive for detection of abnormalities in the distal airways especially when spirometry is normal, as frequently occurs in the severely obese symptomatic patients. The main objective of the proposed study is to evaluate the effect of obesity on quality of life and health care utilization and its relationship to cardiopulmonary disease in an ethnically diverse, underserved obese population by using state-of-the-art diagnostic modalities before and after significant (20%) weight loss.

The investigators propose to perform stress cardiac MRI and pulmonary function testing with oscillometry before and after significant surgical weight loss in 150 severely obese patients with cardiopulmonary symptoms. Patients evaluated in the comprehensive Obesity Center at Bellevue Hospital who meet NIH Consensus Guidelines for Bariatric Surgery, who have cardiopulmonary symptoms, and who meet clinical criteria for cardiac stress testing and pulmonary function testing will be approached by the study personnel and offered enrollment. Informed consent will be obtained. Enrolled patients will undergo clinical evaluation with a detailed medical history including the Borg dyspnea scale, physical examination, laboratory testing including cardiopulmonary biomarkers (brain natriuretic peptide, C-reactive protein, atrial natriuretic peptide), and non-invasive cardiovascular stress MRI and pulmonary physiologic evaluation including spirometry, plethysmography and impulse oscillometry (IOS). Patients with active smoking history and/or asthma will be identified clinically.

Cardiovascular MRI will be performed using a 1.5T (Avanto or Espree, Siemens Healthcare) system. Standard cardiovascular techniques will be used for the assessment of myocardial and vascular structure and function, including T1-weighted, T2-weighted, late gadolinium enhancement, cine, tagged and phase contrast imaging in selected planes. Adenosine stress MRI will be performed for evaluation of underlying coronary artery or microvascular disease.

Condition or disease
Obesity Cardiovascular Abnormalities

Study Type : Observational
Actual Enrollment : 150 participants
Observational Model: Case-Only
Time Perspective: Prospective
Official Title: Effects of Weight Loss on Cardio-respiratory Function and Patient-centered Outcomes in an Underserved, Minority Population With Clinically Severe Obesity
Study Start Date : September 2011
Actual Primary Completion Date : September 2013
Actual Study Completion Date : December 2013

Resource links provided by the National Library of Medicine

Obese group

Primary Outcome Measures :
  1. Effects of body mass & adiposity on airway mechanics and cardiovascular anatomy and physiology. [ Time Frame: 2 years ]
    Detailed evaluation of quality of life, health care utilization and the cardiopulmonary system in severe obesity, with an assessment of the correlation between specific cardiovascular and pulmonary parameters to improve our understanding and treatment of symptomatic obese patients.

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Ages Eligible for Study:   18 Years to 80 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Patients utilizing the Bariatric Clinic services at Bellevue (City/Public) Hospital.

Inclusion Criteria:

Eligible patients for this study are patients who are booked for bariatric surgery and who have cardiopulmonary symptoms that require further cardiopulmonary testing prior to bariatric surgery.

Exclusion Criteria:

Patients with contraindications to MRI examination with gadolinium contrast and adenosine administration will be excluded. Additional exclusions include being deemed unable to comply with the study protocol (either self-selected or by indicating during screening that s/he could not complete all requested tasks), participation in other obesity- or diabetes-related clinical trials, or diagnosis of cognitive dysfunction or significant psychiatric comorbidity.

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To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01410487

United States, New York
Bellevue Hospital Ambulatory Cinic - Suite 1D
New York, New York, United States, 10016
Sponsors and Collaborators
New York University School of Medicine

Responsible Party: New York University School of Medicine Identifier: NCT01410487     History of Changes
Other Study ID Numbers: 11-01998
First Posted: August 5, 2011    Key Record Dates
Last Update Posted: December 2, 2014
Last Verified: December 2014

Keywords provided by New York University School of Medicine:
pulmonary circulation

Additional relevant MeSH terms:
Weight Loss
Cardiovascular Abnormalities
Nutrition Disorders
Body Weight
Signs and Symptoms
Body Weight Changes
Cardiovascular Diseases
Congenital Abnormalities