Hemodynamics, Salt Sensitivity and Body Composition in Patients With Morbid Obesity

Completed

• Conditions: Obesity; Hypertension

• Registration Number: NCT00998465
• Lead Sponsor: Zealand University Hospital

Brief Summary

The purpose of this study is to evaluate the effect of high vs. low sodium intake on blood pressure and system hemodynamics in patients with morbid obesity and to evaluate the impact of laparoscopic gastric bypass on blood pressure, salt sensitivity and body composition in morbidly obese patients. Furthermore, we wants to describe the hemodynamic mechanisms involved in the amelioration of blood pressure during long-term weight loss.

Detailed Description

Overweight and obesity are rapidly increasing in Western countries and are associated with increased mortality and morbidity. The increased morbidity is assumed to be mediated mainly by insulin resistance, diabetes, hypertension and lipid disturbances, but obesity also represents an independent risk factor for cardiovascular disease.

Obesity is associated with an increased risk of hypertension but the pathophysiological basis is not fully established. Several studies have indicated that blood pressure of obese patients could be more dependent on dietary sodium intake than the blood pressure of non-obese patients(as it is the case for patients with essential hypertension)and that this sodium sensitivity of blood pressure is lost after weight loss.

To date, bariatric surgery is the only therapy resulting in substantial and durable long-term weight loss, and the beneficial effects on obesity-related co-morbidities have been well documented. Laparoscopic gastric bypass results in a remarkable improvement of glucose homeostasis and a resolution of diabetes, that typically occurs too fast to be accounted for by weight loss alone. Furthermore, an immediate reduction of blood pressure following laparoscopic gastric bypass has been demonstrated in morbidly obese patients with hypertension as early as one week after the operation. As with the rapid reduction of diabetes, the antihypertensive effect of the procedure might be a consequence of the rearrangement of the gastrointestinal anatomy.

With this study, we want to evaluate the effect of high vs. low sodium intake on blood pressure and system hemodynamics in patients with morbid obesity and to evaluate the impact of laparoscopic gastric bypass on blood pressure, salt sensitivity and body composition in morbidly obese patients. Furthermore, we wants to describe the hemodynamic mechanisms involved in the amelioration of blood pressure during long-term weight loss. Therefore, patients are examined before, 4-6 weeks after and one year after laparoscopic gastric bypass.

Before and one year after the operation, the patients are examined two times; in a five days period of a low dietary sodium consumption and in a five days period of a high sodium consumption respectively. Four-six weeks following the operation, the patients are examined once on their usual diet.

The protocol comprise three sub studies:

1. The effect of high vs low sodium intake on blood pressure and hemodynamics in the morbid obese patient - preoperative study.

2. Effect of gastric bypass surgery on blood pressure, hemodynamics and salt-sensitivity - 1 year follow-up.

3. Effect of gastric bypass surgery on echocardiographic parameters - 1 year follow-up.

Study Timeline

• Study First Submitted: 2009-10-19
• Study First Submitted QC: 2009-10-19
• Study First Posted: 2009-10-20
• Study Start: 2009-11
• Primary Completion: 2012-12
• Study Completion: 2013-01
• Status Verified: 2013-03
• Last Update Submitted: 2013-03-19
• Last Update Posted: 2013-03-20

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 36

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Sodium induced change in 24-hour blood pressure before and one year after laparoscopic gastric bypass.	One year

Secondary Outcome Measures

Name	Time	Method
Non-invasive hemodynamic measurements (inert gas rebreathing) before and one year after laparoscopic gastric bypass	One year
Echocardiography: Dimensions, systolic and diastolic function before and one year after laparoscopic gastric bypass	One year
Body composition: Dexa-scan, plasma volume and extracellular volume before and one year after laparoscopic gastric bypass	One year
Blood samples: MR-proANP, p-glucose, p-insulin	One year

Trial Locations

Locations (1)

University Hospital Koege, Department of Clinical Physiology and Nuclear Medicine; 🇩🇰 Koege, Denmark

University Hospital Koege, Department of Clinical Physiology and Nuclear Medicine

🇩🇰Koege, Denmark