Production of Free Fatty Acids From Blood Triglycerides

This study has been completed.
Sponsor:
Collaborator:
Information provided by:
Mayo Clinic
ClinicalTrials.gov Identifier:
NCT00911482
First received: May 29, 2009
Last updated: November 6, 2012
Last verified: November 2012
  Purpose

The overall hypothesis of these studies is that circulating triglycerides, coming primarily from fat in the diet, are an important source of free fatty acids. Free fatty acids are the major fat fuel in the body, and when they are elevated in the blood they are thought to raise the risk of cardiovascular disease by causing insulin resistance (in some cases leading to diabetes), raising blood pressure, and other effects. The investigator will use sophisticated methods for tracing triglycerides and free fatty acids in the blood. These methods involve the administration of low doses of radioactive and stable isotopes of naturally occurring fats. The studies will determine the contribution of triglycerides to free fatty acids in normal people and also in people with diabetes.


Condition
Diabetes Mellitus, Type 2
Insulin Resistance
Dyslipidemias

Study Type: Observational
Study Design: Time Perspective: Cross-Sectional
Official Title: FFA Production From Triglyceride-Rich Lipoproteins

Resource links provided by NLM:


Further study details as provided by Mayo Clinic:

Primary Outcome Measures:
  • Spillover of free fatty acids from chylomicrons [ Time Frame: Measured at 1 to 6 days ] [ Designated as safety issue: No ]

Biospecimen Retention:   Samples Without DNA

Plasma samples obtained during the study are stored for lipid analysis.


Enrollment: 16
Study Start Date: June 2008
Study Completion Date: January 2012
Primary Completion Date: January 2012 (Final data collection date for primary outcome measure)
Groups/Cohorts
Diabetes/weight loss
12 individuals with type 2 diabetes and hypertriglyceridemia
Nondiabetic/hypertriglyceridemic
10 insulin resistant nondiabetic individuals with dyslipidemia
Normotensive/nondiabetic
10 insulin resistant, normotensive, nondiabetic individuals
Insulin resistant/dyslipidemic
14 insulin resistant nondiabetic individuals with dyslipidemia

Detailed Description:

Lipid energy is transported in the blood in several forms, including chylomicrons and free fatty acids (FFA). Chylomicrons are key elements in the absorption and storage of dietary fat, and also play a role in the pathogenesis of atherosclerosis via the production of remnant particles, but their role as a direct fuel source has not been explored. FFA are the major lipid fuel in the body, and increases in their concentration have been shown to cause insulin resistance, endothelial dysfunction and increases in the production of very low density lipoproteins. FFA are released into the blood through the action of hormone sensitive lipase on triglyceride stores in fat cells. Very little is known about the role of chylomicrons in FFA metabolism, but the potential contribution of chylomicrons to FFA is considerable, especially in people who consume high fat diets. Initial studies indicate that in addition to the role of chylomicrons in fat storage, a portion of chylomicron fatty acids are released as FFA in a process called "spillover". These studies indicate that the contribution of chylomicrons to FFA is increased in type 2 diabetes. A study of spillover in the splanchnic bed found very high rates of splanchnic spillover in overweight and obese individuals with hypertriglyceridemia. Extremely accurate and precise methods have been developed by the investigator for the measurement of the concentration and specific activity of FFA and chylomicron triglyceride fatty acids in plasma. In addition, a tracer method for accurately determining the kinetics of chylomicrons has been developed. In the proposed studies, the tracer technique will be used to systematically investigate the contribution of chylomicrons to total FFA availability. The technique will be applied to normal subjects at rest and after exercise, as well as subjects with type 2 diabetes mellitus and hypertriglyceridemia. Specifically, these studies will: 1) determine whether weight loss in people with type 2 diabetes reduces spillover from chylomicrons; 2) determine whether acute lowering of FFA with insulin infusion reduces spillover in nondiabetic individuals with dyslipidemia; 3) determine whether noninsulin-mediated lowering of FFA reduces spillover in diabetic individuals with dyslipidemia, and 4) determine whether obese, insulin-resistant individuals have increased spillover in the splanchnic bed.

  Eligibility

Ages Eligible for Study:   35 Years to 60 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Sampling Method:   Probability Sample
Study Population

Volunteers from the region around Rochester, Minnesota who meet the inclusion criteria will be recruited.

Criteria

Inclusion Criteria:

  • Type 2 diabetes
  • Atherogenic dyslipidemia
  • Obesity

Exclusion Criteria:

  • Kidney disease
  • Liver disease
  • Coronary artery disease
  • Retinopathy
  • Neuropathy
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00911482

Locations
United States, Minnesota
Mayo Clinic
Rochester, Minnesota, United States, 55905
Sponsors and Collaborators
Mayo Clinic
Investigators
Principal Investigator: John M. Miles, MD Mayo Clinic
  More Information

No publications provided

Responsible Party: John M. Miles, MD, Mayo Foundation
ClinicalTrials.gov Identifier: NCT00911482     History of Changes
Other Study ID Numbers: 08-001493, R01HL067933, R01 HL067933
Study First Received: May 29, 2009
Last Updated: November 6, 2012
Health Authority: United States: Federal Government

Keywords provided by Mayo Clinic:
Type 2 Diabetes
Dyslipidemia
FFA
Triglycerides
Tracers

Additional relevant MeSH terms:
Diabetes Mellitus
Insulin Resistance
Diabetes Mellitus, Type 2
Dyslipidemias
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Hyperinsulinism
Lipid Metabolism Disorders

ClinicalTrials.gov processed this record on September 30, 2014