Beta-Cell Dysfunction, Insulin Resistance, Insulin Sensitivity, Obesity, Prediabetes
Conditions
Keywords
Vitamin K, Vitamin K2, Menaquinone-7, Osteocalcin, Adults, Obesity, Insulin resistance, Insulin sensitivity, Beta-cell function, Prediabetes
Brief summary
Given that glutamate carboxylation or decarboxylation is key to the metabolic role of osteocalcin (at least in mouse models) and that carboxylation is vitamin K dependent, it is critical to isolate the effect of vitamin K manipulation on carboxylation of osteocalcin and its subsequent effect on glucose metabolism in clinical trials. The purpose of this randomized, double-blind, placebo-controlled clinical trial in adults is to determine whether eight weeks of daily supplementation with vitamin K2 (menaquinone-7) can improve markers in blood associated with diabetes risk.
Interventions
DIETARY_SUPPLEMENTPlacebo
Two placebo softgel capsules (containing no vitamin K2) every day for 8 weeks.
DIETARY_SUPPLEMENTLow-Dose Vitamin K2 Supplement (menaquinone-7; 90-mcg/d)
One 90-mcg vitamin K2 softgel capsules (containing no vitamin K2) and one placebo softgel capsule everyday for 8 weeks.
DIETARY_SUPPLEMENTHigh-Dose Vitamin K2 Supplement (menaquinone-7; 180-mcg/d)
Two 90-mcg vitamin K2 softgel capsules every day for 8 weeks.
Sponsors
University of Alabama at Birmingham
Yale University
Tufts University
Augusta University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
1. Healthy adults between 18 and 65 years old 2. Subject understands the study protocol and agrees to comply with it 3. Informed Consent Form signed by the subject
Exclusion criteria
1. Subjects using vitamin supplements containing vitamin k 2. Subjects with (a history of) metabolic or gastrointestinal diseases including hepatic disorders 3. Subjects presenting chronic degenerative and/or inflammatory diseases 4. Subjects receiving systemic treatment or topical treatment likely to interfere with evaluation of the study parameters (salicylates, antibiotics) 5. Subjects receiving corticosteroid treatment 6. Subjects using oral anticoagulants 7. Subjects with a history of soy allergy 8. Subjects who have participated in a clinical study more recently than one month before the current study
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in insulin sensitivity | Change from baseline in insulin sensitivity at 8 weeks | Insulin sensitivity will be calculated from plasma insulin and glucose concentrations measured during a 2-hour oral glucose tolerance test by using the oral glucose minimal model. |
| Change in beta-cell function | Change from baseline in beta-cell function at 8 weeks | Beta-cell function, as assessed by dynamic beta-cell responsitivity, will be calculated from plasma glucose and C-peptide concentrations measured during a 2-hour oral glucose tolerance test by using the oral C-peptide minimal model. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in prothrombin time (PT) | Change from baseline in PT at 8 weeks | — |
| Change in activated partial thromboplastin time (aPTT) | Change from baseline in aPTT at 8 weeks | — |
| Change in arterial stiffness (PWV) | Change from baseline in arterial stiffness at 8 weeks | Arterial stiffness will be assessed using carotid-femoral pulse wave velocity (PWV) by applanation tonometry. |
| Change in endothelial function (FMD) | Change from baseline in endothelial function at 8 weeks | Endothelial function will be assessed using brachial artery flow-mediated dilation (FMD) by ultrasound. |
Countries
United States
Outcome results
None listed