<p>Low Vitamin D Serum Level Is Associated with HDL-C Dyslipidemia and Increased Serum Thrombomodulin Levels of Insulin-Resistant Individuals</p>

Abstract

Background: Insulin-resistant individuals are known to have dyslipidemia and are predicted to be at high risk of cardiovascular events. Vitamin D deficiency was shown to be associated with dyslipidemia; however, the type of dyslipidemia associated with vitamin D deficiency in insulin-resistant individuals is not determined. Furthermore, there is evidence linking insulin resistance with low-grade inflammation suggesting levels of pro-inflammatory cytokines to be increased in insulin-resistant states. Objective: This study was performed to evaluate the impact of vitamin D deficiency, defined as serum level of 25(OH)D below 20 ng/mL, on lipid profile and inflammatory markers such as interleukin (IL-6) and IL-8, as well as soluble thrombomodulin (TM) in the serum of insulin-resistant individuals. Methods: A total of 4114 individuals had simultaneous serum 25(OH)D, insulin, and lipid panel testing during 2013 as part of the United Arab Emirates National Diabetes and Lifestyle (UAEDIAB) study. Multivariate logistic regression analysis was used to assess the association between serum level of 25(OH)D and lipid profile in insulin-sensitive versus-resistan t individuals. The lipid panel was stratified into high total cholesterol (TC: >6.2 mmol/L), high low-density lipoprotein-cholesterol (LDL-C: >2.59 mmol/L), high triglycerides (TG: >2.3 mmol/L), and low high-density lipoprotein-cholesterol (HDL-C: <1.55 mmol/L) dyslipidemia. Furthermore, the immunomodulatory and vasculoprotective effects of 25(OH)D were assessed by measuring the levels of IL-6, IL-8, and soluble TM in serum using ELISA. Results: More than half of the 4114 individuals were insulin resistant (n=2760, 67%) and around one-fifth of them were vitamin D-deficient (n=796, 19%). After adjusting for age, gender, body mass index, smoking, ethnicity, and educational level, the only dyslipidemia associated with vitamin D-deficient-insulin-resistant individuals (OR 2.09 [95]; P=0.009) was lower HDL-C. Furthermore, deficient 25(OH)D individuals with low HDL-C levels had higher circulatory IL-6 and IL-8 levels, and higher serum soluble TM compared to individuals with sufficient 25(OH)D and normal lipid profiles (median, IL-6 pg/mL 0.82 vs 1.71, P=0.001; median, IL-8 pg/mL 51.31 vs 145.6, P=0.003; and median, soluble TM ng/mL 5.19 vs 7.38, P<0.0001; in sufficient vs deficient groups, respectively). Conclusion: The results of our study showed that in insulin-resistant individuals, vitamin D deficiency status is associated with HDL-C dyslipidemia and higher serum inflammatory and endothelial damage markers.

Vitamin D Prevents High Glucose-Induced Lipid Droplets Accumulation in Cultured Endothelial Cells: The Role of Thioredoxin Interacting Protein

“…Of note, it seems that the duration of diabetes rather than glycemic control is associated with VitD deficiency [ 26 ]. Remarkably, observational studies as well as preclinical data support that low VitD correlates with increased risk of hypertension, atherosclerosis, metabolic disorders, and low-grade inflammation, all of which are conditions that share endothelial dysfunction as a common element [ 27 , 28 , 29 ]. Accordingly, through the high-frequency ultrasonographic imaging of the brachial artery to assess endothelium-dependent flow-mediated vasodilation, it was demonstrated that VitD improves endothelial function in VitD-deficient subjects [ 30 ] and in patients with T2D and with low serum levels of VitD [ 31 ].…”

Vitamin D and Its Metabolites Deficiency in Acute Coronary Syndrome Patients Undergoing Coronary Angiography: A Case–Control Study

“… 52 Notably, the active form of vitamin D has both cardioprotective and pleiotropic effects and increases thrombomodulin and decreases tissue factor. 53 …”

“…52 Notably, the active form of vitamin D has both cardioprotective and pleiotropic effects and increases thrombomodulin and decreases tissue factor. 53 In line with our results on the systolic BP as a predictor of ACS, "The Third National Health and Nutrition Examination Survey" has reported a significant increase in the prevalence of hypertension [OR = 1.30, p < 0.001] in patients with low 25(OH)D (<21 ng/mL) compared to those patients with level more than 37 ng/mL. 54 In addition, a study confirmed the relationship between the TC, low-density lipoprotein cholesterol (LDL-C), HDL-C, and non-HDL-C and ACS vs control group.…”

The role of high-dose vitamin D supplementation on disease severity and lipid profile in psoriatic patients: A pilot study

“…13 The previous studies reported that the vitamin D deficiency may be associated with dyslipidaemia in apparently healthy people and in diabetic patients. [14][15][16] Besides, vitamin D deficiency was related to an increased risk of CVD. A meta-analysis of 24 observational studies indicated an inverse relationship between the vitamin D serum level and risk of CVD.…”