Vitamin E or Lipoic Acid on Serum Oxyphytosterol Concentrations

The Effects of Consumption of Vitamin E or Lipoic Acid on Serum Oxyphytosterol Concentrations in Subjects With Impaired Glucose Tolerance or Type II Diabetes

Background of the study:

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. 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 Overview

• Status: Unknown
• Conditions: Oxidative Stress
• Intervention / Treatment: Dietary supplement: Vitamin E; Dietary supplement: Lipoic acid; Dietary supplement: Control

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Netherlands
  • Limburg
    • Maastricht, Limburg, Netherlands, 6229 ER
      • Maastricht University Medical Centre

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Control	Dietary supplement: Control; Daily consumption of 3 placebo capsules
Experimental: Vitamin E	Dietary supplement: Vitamin E; Daily consumption of vitamin E capsules, 3 capsules of 268 mg daily, in total daily consumption of 804 mg
Experimental: Lipoic acid	Dietary supplement: Lipoic acid; Daily consumption of lipoic acid capsules, 3 capsules of 200 mg daily, in total daily consumption of 600 mg

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Plasma oxyphytosterol concentrations	Measured after 4 weeks intervention

Secondary Outcome Measures

Outcome Measure	Time Frame
Serum lipoprotein concentrations	Measured after 4 weeks intervention
Markers reflecting oxidative stress	Measured after 4 weeks intervention
Markers reflecting antioxidant capacity	Measured after 4 weeks intervention

Collaborators and Investigators

• Sponsor: Maastricht University Medical Center
• Collaborators: ZonMw: The Netherlands Organisation for Health Research and Development
• Investigators: Principal Investigator: Jogchum Plat, Prof., Maastricht University Medical Centre

Study record dates

Study Major Dates

• Study Start: April 1, 2013
• Primary Completion (Anticipated): January 1, 2014
• Study Completion (Anticipated): January 1, 2014

Study Registration Dates

• First Submitted: November 8, 2013
• First Submitted That Met QC Criteria: November 8, 2013
• First Posted (Estimate): November 14, 2013

Study Record Updates

• Last Update Posted (Estimate): November 14, 2013
• Last Update Submitted That Met QC Criteria: November 8, 2013
• Last Verified: November 1, 2013

More Information

Terms related to this study

• Keywords: Oxidative stress; Vitamin E; Lipoic acid; Oxyphytosterols
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Protective Agents; Micronutrients; Vitamins; Antioxidants; Vitamin B Complex; Vitamin E; Thioctic Acid
• Other Study ID Numbers: NL40392.068.12 / METC 12-3-047