Metabolic Syndrome X
Conditions
Brief summary
Several lines of evidence indicate that a significant proportion of cardiovascular disease (CVD) events are attributable to the presence of a cluster of metabolic abnormalities and perturbations, defined as the metabolic syndrome. It has been estimated that approximately 25% of the North American adult population is living with the metabolic syndrome. Recent studies show that overaccumulation of atherogenic triglyceride-rich lipoproteins (TRL) seen in insulin-resistant patients is partly due to increased production rate of intestinally derived apolipoproteinB-48-containing lipoproteins. This is of interest because substantial evidence exists indicating that elevated levels of intestinal lipoproteins are associated with increased CVD risk. However, as indicated in the body of this grant proposal, the underlying mechanisms that lead to intestinal overproduction of lipoproteins in insulin-resistant states are poorly understood. The general objective of the proposed research is to investigate the mechanisms by which the metabolic syndrome affects apolipoproteinB-48 secretion in human. The primary hypothesis is that insulin resistance will be associated with higher levels of intestinal lipoproteins because of an increased secretion of these particles.
Interventions
None listed
Sponsors
Canadian Institutes of Health Research (CIHR)
Laval University
Study design
Observational model
CASE_CONTROL
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
MALE
Age
18 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
Subjects with metabolic syndrome: * Men aged between 18-60 years * Waist circumference \>102 * HDL-cholesterol \< 1.1 mmol/L * Triglycerides \> 1.7 mmol/L * Fasting blood glucose \>6.1 mmol/L * Normal blood pressure (\<130/85) Controls: * Men aged between 18-60 years * Waist circumference \>102 * HDL-cholesterol \> 1.1 mmol/L * Triglycerides \< 1.7 mmol/L * Fasting blood glucose \<6.1 mmol/L * Normal blood pressure (\<130/85)
Exclusion criteria
* Women * Men \< 18 or \> 60 years * Smokers (\> 1 cigarette/day) * Body weight variation \> 10% during the last 6 months prior to the study baseline * Subjects with a previous history of cardiovascular disease * Subjects with Type 2 diabetes * Subjects with a monogenic dyslipidemia * Subjects on hypertension medications or medications known to affect lipoprotein metabolism or the integrity of gastrointestinal mucosa * Subjects with endocrine or gastrointestinal disorders * History of alcohol or drug abuse within the past 2 years * Subjects who are in a situation or have any condition that, in the opinion of the investigator, may interfere with optimal participation in the study
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Change in TRL apolipoproteinB-48 production rate. | Week 1 |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in duodenal expression of genes that regulate intestinal lipid synthesis. | Week 1 | Genes that regulate intestinal lipid synthesis that will be measured are Acyl-Coenzyme A (CoA): diacylglycerol acyltransferase (DGAT), Acyl-CoA:cholesterol O-transferase 2 (ACAT2) and 3-hydroxy-methylglutaryl-CoA reductase (HMG CoA reductase). |
| Change in synthesis of apolipoproteinB-48 containing lipoproteins (Microsomal triglyceride transfer protein (MTP), apolipoproteinB-48). | Week 1 | — |
| Changes in duodenal expression of genes that regulate intestinal lipid absorption. | Week 1 | Genes that regulate intestinal lipid absorption that will be measured are Niemann-Pick C1-like-1 (NPC1L1), Adenosine triphosphate(ATP)-binding cassette transporters (ABCG5/8), Fatty Acid Binding Protein (FABP), Sterol Regulatory Element Binding Protein (SREBP) |
Countries
Canada
Outcome results
None listed