The effect of menaquinone-7 (MK-7) supplementation on metabolic, nutritional, inflammatory status and matrix γ-carboxyglutamate protein in patients with type 2 diabetes mellitus

Abstract

Background and objective: Type 2 diabetes mellitus (T2DM) is common metabolic disease with an increasing trend in the world that has many acute and chronic complications. Hyperglycemia, dyslipidemia and inflammation are common disorders of this disease. One of the important factors in diabetes control, is supplementation of effective vitamins and it seems that vitamin K supplemention can be an effective factor in controlling diabetes and especially glycemic control. This study was conducted to examine the effects of menaquinone (MK-7 200 mcg/day) supplementation on metabolic status (glycemic indices and lipid profile), nutritional status (anthropometric measures and body composition), inflammatory status and functional markers of vitamin K status in type 2 diabetes patients.

Methods and Materials: In this double-blind placebo-controlled randomized clinical trial, 60 men and women with type 2 diabetes were allocated equally into either the MK-7 or the placebo group. Physical activity level and dietary intake were assessed using the international physical activity questionnaire-short form and a 3-day food record, pre and post intervention. Anthropometric measures (weight, body mass index, waist circumference, hip circumference, waist to hip ratio), body composition (fat mass, fat free mass, total body water), glycemic indices (Fasting Insulin, FBS, HbA1c, HOMA-IR), lipid profile (TG, TC, HDL-C, LDL-C), inflammatory status (TNF-α, hs-CRP, IL-6) and functional markers of vitamin K status including dephosphorylated un-carboxylated matrix γ-carboxyglutamate protein (dp-ucMGP) and prothrombin induced by vitamin K absence (PIVKA-II).

Results: Forty-five patients completed the trial. There were no significant differences in calorie and macronutrient intake as well as physical activity level at baseline and at the end of the study. Dietary vitamin K intake increased significantly at the end of the study in the MK-7 and placebo groups (p < 0.05), but intergroup differences were not significant. Serum levels of fasting blood sugar, glycated hemoglobin A1c, insulin and homeostatic model assessment of insulin resistance decreased significantly in the MK-7 group (p < 0.05). While after adjustment for the baseline values and changes of vitamin K intake at the end of study, only FBS and HbA1c were significantly lower in the MK-7 group compared to the placebo group (p < 0.05). Lipid profile and body composition indices did not change significantly within or between groups. About antropometric indices, although weight increased significantly in the placebo group and hip circumference decreased significantly in MK-7 group but no statistically significant between groups differences were observed at the end of the study. Serum levels of inflammatory markers including high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) and also serum levels of prothrombin induced by vitamin K absence (PIVKA-II) and dephospho uncarboxylated matrix γ-carboxyglutamate protein (dp-ucMGP) as vitamin K markers decreased significantly in the MK-7 group (p <0.05). Also, after adjustment for baseline values and changes of vitamin K intake, the between group differences were significant for PIVKA-II at the end of study (p < 0.05).

Conclusion: It seems that MK-7 supplementation can be effective in improvement of glycemic indices and functional markers of vitamin K status in patients with type 2 diabetes, although further studies are needed.