Discussion
rheumatoid arthritis, TG, diabetes
RHEUMATOID ARTHRITIS, INSULIN RESISTANCE, HIGH INSULIN, TYPE 2 DIABETES, INSULIN SENSITIVITY, DIABETES
In the current study, we demonstrated that vitamin K4 supplementation for 24 weeks was capable of reducing FSI and insulin resistance assessed by HOMA-IR with no significant effects on FPG or 2-h PP PG levels or HbAVitamin K3, which is formed following vitamin K4 intake, is assessed to be more potent than natural vitamin Ks and serves as a precursor to vitamin K2 inside the body [Studying the effect of vitamin K4 on glycaemic control of individuals with type 2 diabetes in the current study revealed a significant decrease in the fasting serum insulin and HOMA-IR in the intervention group compared to the placebo group after 24 weeks. Most interventional studies that used vitamin K1 as a supplementation form reported no effect on insulin resistance. The study by Rasekhi et al. reported a significant reduction in postprandial glucose and postprandial insulin and significant increase in insulin sensitivity index with no effect on FSI or insulin resistance upon 4 weeks of vitamin K1 supplementation [Likewise, another thesis illustrated that the administration of 500 µg vitamin K1 daily for 3 weeks did not affect HOMA-IR [In contrast, studies that adopted vitamin K2 as a supplementation form showed more promising results in improving insulin resistance. Two recent studies [In the present study, vitamin K4 supplementation was shown to significantly reduce serum TG and VLDL in individuals with type 2 diabetes with no significant effects on serum cholesterol. Similarly, another study investigated the effect of 8-week vitamin K1 supplementation in female patients with rheumatoid arthritis concluded that it has no effect on any of the lipid profile markers [For a long time, insulin resistance and high insulin levels have been linked to increased levels of VLDL and triglycerides [Although, there is a debate about the sufficient daily intake of vitamin K, our study population seemed to consume sufficient amounts of phylloquinone which constitutes around 90% of vitamin K dietary intake [The current trial has many points of strength. These may include a relatively long follow-up period in addition to reporting the change in patients treatment across the follow-up period. Given that this was a single-centred trial, this ensured similar dietary vitamin K consumption among the study participants across the follow-up period because their socioeconomic level was very close. Furthermore, this study is a valuable addition to the current evidence of the role of vitamin K in diabetes since patients were supplemented with a vitamin K form that is investigated for the first time.One limitation of the study is that vitamin K-dependent proteins like osteocalcin were not assessed. Also, the drop-out rate was relatively high which was attributed to the interruption of the study period by COVID-19 lockdown. Moreover, the assessment of dietary vitamin K intake depended mainly on a picture-based form of vitamin K rich food besides the lack of assessment of caloric, fibres, and other nutrients intake. Yet, picture-based assessment was the most feasible method as there were some illiterate subjects among the study participants. Besides, the compliance of patients to their antidiabetic medication was not contemplated. Also, patients were not educated nor followed-up for changes in their physical activity.In conclusion, 1 mg vitamin K4 supplementation might help in the reduction of insulin resistance in individuals with type 2 diabetes which could help in the reduction of the required antidiabetic treatment doses. Besides, it may have a role in the reduction of serum TG and VLDL. More controlled studies with higher doses of supplementation and longer duration would be important to clarify if there is possible effect on blood glucose levels and long-term glycaemic control as measured by HbA