Fat Gain and Cardiovascular Disease Mechanisms

Obesity Clinical Trial

Official title:

Fat Gain and Cardiovascular Disease Mechanisms

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00589498
• Other study ID #: 652-03
• Secondary ID: NIH HL-073211
• Status: Completed
• Phase: Phase 3
• First received: January 7, 2008
• Last updated: November 1, 2013
• Start date: December 2005
• Est. completion date: December 2012

Study information

• Verified date: November 2013
• Source: Mayo Clinic
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial Summary

Understanding the mechanisms of obesity-induced hypertension is important both for prevention and therapy. Studies of patients with established obesity have provided valuable information on pathophysiologic links between obesity and both blood pressure and cardiovascular risk. However, these studies are necessarily limited by the heterogeneity of obesity-associated disease so that the relative contribution of obesity or hypertension or other co-existing diseases to specific regulatory abnormalities is often not clear. Clarification of whether any abnormalities associated with increased cardiovascular risk were present before or after the development of obesity has also been problematic.

We therefore propose a series of novel studies directed at establishing the effects of increased body fat in otherwise healthy individuals. We will determine the distribution patterns of increased body fat and how both increased body fat and fat distribution relate to changes in blood pressure, and in neural, endothelial and inflammatory mechanisms which have been implicated in the development and progression of cardiac and vascular disease.

We will study non-obese subjects with and without a family history of hypertension. These subjects will undergo an eight-week program of overfeeding with the objective of inducing a 4 kg fat gain. We will determine the nature of fat distribution in these individuals after the fat gain program and subsequently after an eight-week period of weight loss and restoration of normal body weight. Measurements will be compared to those obtained in a matched control group with and without a family history of hypertension, who will continue their normal diets. We will test the following hypotheses:

• Individuals with a family history of hypertension will gain more visceral fat and upper body subcutaneous fat and will have greater blood pressure increases with overfeeding- compared with those without such a family history.

• For all overfed subjects, increases in blood pressure and insulin resistance with fat gain will be most marked in those individuals with a predominantly upper body and visceral fat accumulation.

• Upper body and visceral fat gain will also be associated with greater impairment in cardiovascular function, higher nocturnal blood pressures and an increased likelihood of sleep disordered breathing.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 69
• Est. completion date: December 2012
• Est. primary completion date: December 2012
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 18 Years to 40 Years

Eligibility

Inclusion Criteria:

• We will enroll up to 180 subject in order to fulfill screening requirements and have complete studies in 120 total (60 with and 60 without family history hypertension).

• Gender: Male and female.

• Ages: 18 to 40 (inclusive).

Exclusion Criteria:

• Body-mass index > 33 kg/m2

• Tobacco smoking or chewing

• Shift worker

• Any diseases

• Any prescription medications (except, oral contraceptives are permitted)

Study Design

Allocation: Randomized, Intervention Model: Parallel Assignment, Masking: Single Blind (Outcomes Assessor), Primary Purpose: Prevention

Related Conditions & MeSH terms

• Cardiovascular Diseases
• Hypertension
• Obesity
• Sleep Apnea Syndromes

Intervention

Dietary Supplement:
• 1000 extra calories
Each subject received 1000 kcal/d in addition to weight maintenance requirements. The diet composition throughout the study was 40% carbohydrate, 40% fat, and 20% protein.

Locations

Country	Name	City	State
United States	Mayo Clinic	Rochester	Minnesota

Sponsors (2)

Lead Sponsor	Collaborator
Mayo Clinic	National Institutes of Health (NIH)

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Individuals with a family history of hypertension will gain more visceral fat and upper body subcutaneous fat and will have greater blood pressure increases with overfeeding- compared with those without such a family history.		conclude the 180 patients recruited	No
Secondary	* For all overfed subjects, increases in blood pressure and insulin resistance with fat gain will be most marked in those individuals with a predominantly upper body and visceral fat accumulation.		after recruiting at least 70 patients	No
Secondary	Upper body and visceral fat gain will also be associated with greater impairment in cardiovascular function, higher nocturnal blood pressures and an increased likelihood of sleep disordered breathing		Recruit at least 70 subjects	No
Secondary	Increased weight gain, particularly in the upper body and visceral regions, will be accompanied by enhanced production of inflammatory mediators linked to cardiovascular risk, including adhesion molecules and C-reactive protein.		Recruit at least 70 patients	No
Secondary	These changes will resolve with subsequent loss of weight at the end of the overfeeding program and restoration of normal body fat and fat distribution.		Recruit at least 70 patients	No

External Links

•   Mayo Clinic Clinical Trials