Vitamin K and Glucose Metabolism in Children at Risk for Diabetes (Vita-K 'n' Kids Study)

Not Applicable

• Conditions: Insulin Resistance; Obesity; Diabetes; Insulin Sensitivity; Prediabetes; Dyslipidemia
• Interventions: Dietary Supplement: Low-Dose Vitamin K2 (menaquinone-7; 45 mcg/d); Dietary Supplement: High-Dose Vitamin K2 (menaquinone-7; 90 mcg/d); Dietary Supplement: Placebo-Control

• Registration Number: NCT01972113
• Lead Sponsor: Augusta University

Brief Summary

The undercarboxylated fractions of the two vitamin K-dependent proteins osteocalcin and matrix Gla protein have been shown to play key roles in type 2 diabetes and cardiovascular disease (at least in mouse models). Clinical trials are needed to isolate the effects of vitamin K manipulation on carboxylation of these two proteins (osteocalcin and matrix GLA protein) and their subsequent effects on markers of diabetes and cardiovascular disease risk. The purpose of this pilot randomized, double-blind, placebo-controlled trial in children is to estimate the effective dose of vitamin K2 (menaquinone-7) supplementation (to improve carboxylation of both osteocalcin and matrix Gla protein), and whether it can have an effect on markers associated with diabetes and cardiovascular disease risk.

Detailed Description

Not available

Study Timeline

• Study Start: 2013-09
• Study First Submitted: 2013-10-24
• Study First Submitted QC: 2013-10-24
• Study First Posted: 2013-10-30
• Status Verified: 2019-11
• Last Update Submitted: 2019-11-18
• Last Update Posted: 2019-11-19
• Primary Completion: 2020-08-30
• Study Completion: 2020-12-30

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 30

Inclusion Criteria

• Age 8 to 17 years
• BMI less than 85th percentile for age and gender
• Subject and parent/guardian understands the study protocol and agrees to comply with it
• Informed Consent Form signed by the parent/guardian and assent signed by the subject

Exclusion Criteria

• Subjects using vitamin supplements containing vitamin k
• Subjects with (a history of) metabolic or gastrointestinal diseases including hepatic disorders
• Subjects presenting chronic degenerative and/or inflammatory diseases
• Subjects receiving systemic treatment or topical treatment likely to interfere with evaluation of the study parameters (salicylates, antibiotics)
• Subjects receiving corticosteroid treatment
• Subjects using oral anticoagulants
• Subjects with a history of soy allergy
• Subjects who have participated in a clinical study more recently than one month before the current study

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Low-Dose Vitamin K2 (45 mcg/d)	Low-Dose Vitamin K2 (menaquinone-7; 45 mcg/d)	The low-dose vitamin K2 group will take one 45-mcg vitamin K2 softgel capsule and one placebo softgel capsule every day for 8 weeks.
High-Dose Vitamin K2 (90 mcg/d)	High-Dose Vitamin K2 (menaquinone-7; 90 mcg/d)	The high-dose vitamin K2 group will take one 90-mcg vitamin K2 softgel capsules every day for 8 weeks.
Placebo-Control	Placebo-Control	The placebo-control group will take one placebo softgel capsules every day for 8 weeks.

Primary Outcome Measures

Name	Time	Method
Change in serum lipid concentrations	8 weeks	To determine if vitamin K supplementation improves fasting lipid panel (triglycerides, total cholesterol, HDL-cholesterol, and LDL-cholesterol) in a dose-dependent manner.
Change in insulin sensitivity	8 weeks	To determine if vitamin K supplementation improves insulin sensitivity in a dose-dependent manner. Insulin sensitivity will be calculated from plasma insulin and glucose concentrations measured during a 2-hour glucose tolerance test by using the oral glucose minimal model.
Change in beta-cell function	8 weeks	To determine if vitamin K supplementation improves insulin sensitivity in a dose-dependent manner. 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 glucose tolerance test by using the oral C-peptide minimal model.

Secondary Outcome Measures

Name	Time	Method
Change in coagulation	8 weeks	Coagulation-related parameters (i.e., prothrombin time and activated partial thromboplastin time) will be assessed at baseline and 8 weeks to assess clotting function.
Change in arterial stiffness (pulse wave velocity)	8 weeks	Arterial stiffness, as measured by pulse wave velocity (PWV), will be assessed at baseline and 8 weeks to explore whether change in arterial stiffness is influenced by vitamin K2 supplementation.
Change in endothelial function (Flow-mediated dilation)	8 weeks	Endothelial function, as measured by flow-mediated dilation (FMD), will be assessed at baseline and 8 weeks to explore whether change in endothelial function is influenced by vitamin K2 supplementation.
Effects of sex, race, bone age, and pubertal stage on changes in glucosemetabolism (insulin sensitivity and beta-cell function)	8 weeks	Moderation effects of sex, race, bone age, and pubertal stage in the associations of vitamin K-induced changes in carboxylation of osteocalcin on markers of glucose metabolism will be determined.

Trial Locations

Locations (1)

Medical College of Georgia; Augusta University; 🇺🇸 Augusta, Georgia, United States