The major objective of the present study is to examine the effect of consuming vitamin E (804 mg) or lipoic acid (600 mg) for 4 weeks on fasting oxyphytosterol concentrations in subjects with impaired glucose tolerance or type 2 diabetes.
ID
Source
Brief title
Condition
- Lipid metabolism disorders
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
Blood samples will be drawn at week 1, 3 and 4 of each test period. The samples
will be analysed for serum / plasma concentrations of plant sterols and
oxyphytosterols.
Secondary outcome
Samples will also be analysed for oxidative stress markers, antioxidant
capacity, lipoproteins, and for markers reflecting low-grade systemic
inflammation and endothelial dysfunction.
Background summary
We now know that plant sterols can oxidize, which results in the formation of
oxyphytosterols. Animal studies have suggested that oxyphytosterols are
atherogenic components, however this relation has not yet been studied in
humans. In our previous study (METC 09-3-088) we have shown in healthy
volunteers that serum oxyphytosterol concentrations are linked to oxidative
stress status (i.e. we were able to identify high and low sterol oxidizers).
From the literature is known that especially type II diabetics and IGT subjects
are characterized by increased oxidative stress markers and reduced antioxidant
capacity. For this reason we also want to evaluate the oxyphytosterol
concentrations in this population. Moreover, we know propose to evaluate the
effect of antioxidant supplementation, i.e. vitamin E or lipoic acid, on serum
oxyphytosterol concentrations in type II diabetic patients. If possible to
lower oxyphytosterol concentrations in these populations this is obviously
beneficial in case oxyphytosterols turn out to be atherogenic.
Study objective
The major objective of the present study is to examine the effect of consuming
vitamin E (804 mg) or lipoic acid (600 mg) for 4 weeks on fasting
oxyphytosterol concentrations in subjects with impaired glucose tolerance or
type 2 diabetes.
Study design
The study design will be a randomized, double-blind, placebo-controlled
cross-over design. The total study duration will be 20 weeks, consisting of 3
test periods of 4 weeks in which subjects will use the investigational
products. Each period will be separated by a washout period of 4 weeks.
Intervention
Subjects will be asked to consume three times daily control capsules, vitamin E
capsules (total 804 mg) or lipoic acid capsules (total 600 mg) for three
periods of four weeks. They will be asked to consume these capsules daily,
divided over three eating moments. Each test-period is separated by a washout
period of 4 weeks, during which the subjects will return to their normal
patterns (indicating no vitamin supplementation). Of course they are not
allowed to consume vitamin E or lipoic acid supplements during the washout
periods. In total they will visit the department on 9 occasions to give a blood
sample.
Study burden and risks
Blood samples will be drawn on 9 different occasions in a time frame of 20
weeks with a total amount of 178.5 mL. During the screening procedure 9 mL (2x
3.5 ml, 1x 2.0 ml) blood will be sampled. Furthermore, subjects will be asked
to fill out a food frequency questionnaire three times at the end of each
experimental period. Apart from a haematoma or bruise, which can occur during
or after venepuncture, no side effects of the intervention itself are expected.
Universiteitsingel 50 50
Maastricht 6229 ER
NL
Universiteitsingel 50 50
Maastricht 6229 ER
NL
Listed location countries
Age
Inclusion criteria
Aged between 18 and 75 years
Body Mass Index (BMI) between 20-35 kg/m2
Mean serum total cholesterol <8.0 mmol/L
Mean serum triacylglycerol <3.0 mmol/L
Diagnosed with diabetes mellitus type 2 on a clinical basis or impaired glucose tolerance (defined as blood glucose >7.8 mmol/l and <11.0 mmol/L, two hours after ingesting 75 gram glucose in 150 ml water)
Exclusion criteria
Unstable body weight (weight gain or loss > 3 kg in the past two months)
Active cardiovascular diseases like congestive heart failure or recent (<6 months) event (acute myocardial infarction, cerebral vascular incident)
Severe medical conditions that might interfere with the study such as epilepsy, asthma, chronic obstructive pulmonary disease, inflammatory bowel disease and rheumatoid arthritis
Use of medication such as corticosteroids, diuretics or lipid lowering therapy
Use of insulin therapy
Abuse of drugs or alcohol (>21 units per week)
Not willing to stop the consumption of vitamin supplements, containing lipoic acid and/or vitamin E, 1 month before the start of the study (wash-in period)
Use of an investigational product within another biomedical study within the previous month
Pregnant or breast-feeding women
Current smoker
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL40392.068.12 |