Effects of Weight Loss on Cardio-respiratory Function

This study is ongoing, but not recruiting participants.
Sponsor:
Information provided by (Responsible Party):
New York University School of Medicine
ClinicalTrials.gov Identifier:
NCT01410487
First received: August 3, 2011
Last updated: September 16, 2013
Last verified: September 2013
  Purpose

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
Obesity
Cardiovascular Abnormalities

Study Type: Observational
Study Design: 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

Resource links provided by NLM:


Further study details as provided by New York University School of Medicine:

Primary Outcome Measures:
  • Effects of body mass & adiposity on airway mechanics and cardiovascular anatomy and physiology. [ Time Frame: 2 years ] [ Designated as safety issue: No ]
    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.


Estimated Enrollment: 150
Study Start Date: September 2011
Estimated Study Completion Date: December 2013
Estimated Primary Completion Date: September 2013 (Final data collection date for primary outcome measure)
Groups/Cohorts
Obese group

  Eligibility

Ages Eligible for Study:   18 Years to 80 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population

Patients utilizing the Bariatric Clinic services at Bellevue (City/Public) Hospital.

Criteria

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.

  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT01410487

Locations
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
  More Information

No publications provided

Responsible Party: New York University School of Medicine
ClinicalTrials.gov Identifier: NCT01410487     History of Changes
Other Study ID Numbers: 11-01998
Study First Received: August 3, 2011
Last Updated: September 16, 2013
Health Authority: United States: Institutional Review Board

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

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

ClinicalTrials.gov processed this record on July 26, 2014