Elevated Circulating FFA and Intrahepatic Lipid Content

This study is currently recruiting participants. (see Contacts and Locations)
Verified May 2013 by Maastricht University Medical Center
Sponsor:
Information provided by (Responsible Party):
Maastricht University Medical Center
ClinicalTrials.gov Identifier:
NCT01177332
First received: August 2, 2010
Last updated: May 30, 2013
Last verified: May 2013
  Purpose

There is increasing evidence that hepatic lipid content (IntraHepatic Lipid, IHL) markedly increases the risk of metabolic complications, including insulin resistance and cardiovascular events. The investigators hypothesize that the liver is passively taking up free fatty acids (FFA) when the availability is high, thereby leading to an increased storage. To test this hypothesis, the investigators want to manipulate FFA levels, by means of a fasted exercise and recovery protocol, and monitor IHL content and hepatic Adenosine triphosphate (ATP) and inorganic phosphate (Pi) concentrations.


Condition Intervention
Diabetes
Hepatic Steatosis
Other: exercise

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Open Label
Primary Purpose: Basic Science
Official Title: Effects of Acute Elevation of Circulating Fatty Acids on Hepatic Lipid Accumulation and Metabolism in Healthy Overweight and Obese Men

Resource links provided by NLM:


Further study details as provided by Maastricht University Medical Center:

Primary Outcome Measures:
  • Intrahepatic lipid content (IHL) and hepatic ATP and PI concentrations [ Time Frame: Day 1 ] [ Designated as safety issue: No ]
    After a baseline MRI/MRS-scan, subjects will cycle for two hours, immediately after cycling another MRI/MRS-scan will be performed and again four hours post exercise. The baseline and the 4-hour post exercise MRI/MRS scans take about 1.5 hour, including both determination of IHL content, by 1H-MRS, and hepatic ATP and Pi concentrations, by 31P-MRS. The MRI/MRS scan performed directly after exercise will take about 45 min, because here only the IHL content will be determined.

  • Intrahepatic lipid content (IHL) and hepatic ATP and PI concentrations [ Time Frame: Day 8 ] [ Designated as safety issue: No ]
    After a baseline MRI/MRS-scan, subjects will cycle for two hours, immediately after cycling another MRI/MRS-scan will be performed and again four hours post exercise. The baseline and the 4-hour post exercise MRI/MRS scans take about 1.5 hour, including both determination of IHL content, by 1H-MRS, and hepatic ATP and Pi concentrations, by 31P-MRS. The MRI/MRS scan performed directly after exercise will take about 45 min, because here only the IHL content will be determined.


Secondary Outcome Measures:
  • Substrate oxidation and blood plasma levels of FFA, triglycerides, glucose and catecholamines [ Time Frame: Day 1 ] [ Designated as safety issue: No ]
  • Substrate oxidation and blood plasma levels of FFA, triglycerides, glucose and catecholamines [ Time Frame: Day 8 ] [ Designated as safety issue: No ]

Estimated Enrollment: 12
Study Start Date: April 2010
Estimated Study Completion Date: December 2013
Estimated Primary Completion Date: December 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: exercise
Two-hour cycling test, fasted or with glucose
Other: exercise
2 hours cycling exercise at 50 % of maximal power output

Detailed Description:

In the Netherlands and worldwide, the number of individuals suffering from type 2 diabetes mellitus is rising steadily. As a consequence, a dramatic increase in diabetes-related morbidity and mortality can be expected over the next few decades. Accordingly, a concerted effort aimed at reducing diabetes rates and towards effective diabetes management is needed.

One of the earliest hallmarks of type 2 diabetes is resistance of the peripheral tissues liver and muscle to the action of insulin, which is generally referred to as insulin resistance. Development of insulin resistance is strongly promoted by obesity. In fact obesity is the major risk factor for insulin resistance, and 80% of all type 2 diabetic patients are overweight or obese. Whereas obesity is by definition characterized by an excessive accumulation of fat in the body, it is specifically the accumulation of fat within peripheral tissues (called steatosis or ectopic fat accumulation), which is associated with the development of insulin resistance. Indeed, type 2 diabetic patients and their first-degree relatives are characterized by excessive accumulation of fat in skeletal muscle. Similarly, the presence of fatty liver in patients with type 2 diabetes and obesity has long been reported. This accumulation of fat in the liver markedly increases the risk for metabolic complications, including insulin resistance and cardiovascular events. Despite the well-known detrimental effects of ectopic fat accumulation, it is not completely understood why fat accumulates in muscle and liver.

In recent years, non-invasive methods like proton magnetic resonance spectroscopy (1H-MRS) have been developed for quantifying lipid content in skeletal muscle and the liver, and were frequently applied by us and others. These measurements can be combined with other Magnetic Resonance techniques to investigate hepatic ATP- and Pi concentrations, determined by phosphorus magnetic resonance spectroscopy (31P-MRS). Furthermore, it has been shown that ATP- and Pi concentrations are lower in subjects with type 2 diabetes mellitus, who are characterized by hepatic lipid accumulation and hepatic insulin resistance. It has been suggested that a decreased ATP and Pi concentration may be an underlying factor for hepatic lipid accumulation.

Human studies using hepatic 1H-MRS reported that intrahepatic lipid (IHL) content is associated with obesity, the metabolic syndrome and diabetes. Furthermore, a period of 36 hours of fasting increased IHL dramatically. These conditions are characterized by elevated plasma FFA levels. We hypothesize that an increased passive uptake of FFAs can lead to a mismatch between uptake and oxidation when FFA availability is high.

Interestingly, results in skeletal muscle show that elevation of FFA levels by lipid infusion result in increased lipid content after 4 hours. Similarly, we showed that skeletal muscle lipid content is increased in the inactive arm muscle after prolonged cycling exercise in the fasted state, where FFA typically increase to up to 1450 mmol. These results suggest that high circulatory FFA levels lead to unrestrained uptake of these FA in skeletal muscle, independent of oxidative needs. Whether IHL accumulation is also the resultant of elevated plasma FFA levels is currently unknown.

Please note that in the study cited above, whereas skeletal muscle lipid content increased in the inactive arm muscle, it decreased in the active vastus lateralis muscle, reflecting the use of intramuscular lipid stores as substrate during prolonged muscular activity. Whether intensified use of IHL during exercise also leads to a decrease in IHL is presently unknown.

  Eligibility

Ages Eligible for Study:   40 Years to 65 Years
Genders Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Male sex
  • Age 40-65 years
  • Overweight/obese, BMI 25-35 kg/m2
  • Healthy
  • Stable dietary habits
  • No medication use

Exclusion Criteria:

  • Female sex
  • Fasting plasma glucose >6.1 mmol/l
  • Haemoglobin <7.8 mmol/l
  • Engagement in programmed exercise > 2 hours total per week
  • Elevated liver enzymes: ALAT > 45 U/L, ASAT > 35 U/L, ALP> 140 U/L, Gamma-GT > 70 U/L
  • Hypertension: blood pressure > 140 mmHg systolic or 90 mmHg diastolic
  • First degree relatives with history of liver disease and diabetes mellitus
  • Any medical condition requiring treatment and/or medication use
  • Alcohol consumption of more than 20 g per day (± 2 units)
  • Unstable body weight (weight gain or loss > 3 kg in the past three months)
  • Participation in another biomedical study within 1 month prior to the screening visit
  • Contraindications for MRI scan
  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: NCT01177332

Contacts
Contact: Lena Bilet, Master 003143-84258 l.bilet@maastrichtuniversity.nl
Contact: Patrick Schrauwen, Doctor 003143-81502 p.schrauwen@maastrichtuniversity.nl

Locations
Netherlands
Department of Human Biology, Maastricht University Recruiting
Maastricht, Netherlands, 6200 MD
Contact: Lena Bilet, Master    003143-842558    l.bilet@hb.unimaas.nl   
Contact: Patrick Schrauwen, Doctor    003143-81502    p.schrauwen@hb.unimaas.nl   
Principal Investigator: Lena Bilet Bilet, Master         
Sponsors and Collaborators
Maastricht University Medical Center
Investigators
Study Director: Patrick Schrauwen, Doctor
  More Information

No publications provided

Responsible Party: Maastricht University Medical Center
ClinicalTrials.gov Identifier: NCT01177332     History of Changes
Other Study ID Numbers: MEC 10-3-024
Study First Received: August 2, 2010
Last Updated: May 30, 2013
Health Authority: Netherlands: The Central Committee on Research Involving Human Subjects (CCMO)

Keywords provided by Maastricht University Medical Center:
FFA
Liver
steatosis
exercise

Additional relevant MeSH terms:
Fatty Liver
Liver Diseases
Digestive System Diseases

ClinicalTrials.gov processed this record on September 29, 2014