The association of vitamin D levels and insulin resistance

Comparative proteomic exploration of plasma proteins in different levels of vitamin D with type 2 diabetes mellitus using iTRAQ-coupled LC-MS/MS

Objectives

Due to the variety of modern diet and lifestyle changes, China has become the world's largest number of people with T2DM. How to prevent and cure T2DM has become one of the urgent public health events in China. Numerous studies have demonstrated vitamin D (VitD) was independently correlated with insulin sensitivity and β cells function. VitD deficiency occurs in about 70% to 80% of patients with T2DM. However, the reason of T2DM patients suffering from VitD deficiency is not very clear. The aim of this project is to identify biomarkers to explore potential mechanism of VitD deficiency in patients with T2DM.

Methods

We used the iTRAQ-coupled LC-MS/MS technique to screen differential expression proteins between VitD deficiency group and VitD sufficiency group in T2DM patients. Then we carried out hierarchical clustering analysis, Gene Ontology classification and enrichment analysis, KEGG pathway enrichment analysis, protein-protein interaction network (PPI) analysis and ELISA validation.

Results

We identified 63 differentially expressed proteins, 17 proteins were up-regulated and 46 proteins were down-regulated (VitD sufficiency vs. VitD deficiency). We ultimately selected four proteins, Podocalyxin (PODXL), ICAM3, MMP9, ApoF for further verification. As a result, the level of MMP9 and ICAM3 was higher in VitD sufficiency group than VitD deficiency group.

Conclusions

Our study provided a solid theoretical foundation for the study of biomarkers and their mechanisms in most patients with T2DM who suffer from vitamin D deficiency. In addition, MMP9 and ICAM3 may play critical roles in the process of VitD deficiency in T2DM.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-024-01456-w.

Seasonal and sex-related variation in vitamin D status and its association with other biochemical markers in young individuals: A cross-sectional study

BACKGROUND

While several studies have investigated the association between vitamin D deficiency and biochemical parameters, the results are still inconsistent and mostly overlook seasonal variations. This study explored the relationships between 25-hydroxy-vitamin D (25(OH)D) concentrations, biochemical markers, and seasonal variation among young males and females.

METHODS

A cross-sectional study was conducted among 203 individuals aged 18-24 years of both sexes residing in Brasilia, Brazil (latitude: 15°S). Sociodemographic variables, season of blood collection, and serum levels of 25(OH)D, total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, glycated hemoglobin (HbA1c), glucose, insulin, hs-CRP, parathyroid hormone, ionized calcium, and alkaline phosphatase were included. Descriptive statistics and differences among groups, correlations, and linear regression tests were performed.

RESULTS

The mean age of the participants was 21.17±1.7 years, and the mean serum 25(OH)D level was 25.76±7.0 ng/mL. Of the participants, 50.7% had vitamin D insufficiency (20 to 29.9 ng/mL), and 23.2% were vitamin D deficient (≤20 ng/mL). Vitamin D deficiency was higher in the spring (53.2%) and among females (29.5%). In young men with vitamin D insufficiency/deficiency (≤29.9 ng/mL) (n = 49), 25(OH)D levels were inversely correlated with HOMA-β (r = -0.234, p = 0.032) and triglyceride (r = -0.415, p = 0.003) levels. However, there were no significant correlations between 25(OH)D concentrations and biochemical markers among women with insufficient and deficient vitamin D levels.

CONCLUSION

This study found a high prevalence of vitamin D insufficiency/deficiency among young individuals living in Brasília, Brazil, particularly women and during the spring season. Our findings suggest that lower 25(OH)D levels (≤29.9 ng/mL) may be associated with insulin resistance and an increased risk of cardiovascular disease in young men studied. However, further studies with larger representative samples are needed to explore the mechanisms underlying the association between vitamin D and biochemical parameters.

High glucose-induced injury in human umbilical vein endothelial cells is alleviated by vitamin D supplementation through downregulation of TIPE1

BACKGROUND

Diabetes mellitus (DM) and its associated vascular complications have become a worldwide health concern. The effects and mechanism of vitamin D supplementation on endothelial function under high glucose condition remain elusive.

METHODS

Human umbilical vein endothelial cells (HUVECs) were treated with 35 mM glucose, then 100 nM vitamin D were added. Transwell migration assay, CCK-8, immunofluorescence, flow cytometry, autophagy flux and transmission electric microscope were performed.

RESULTS

Vitamin D reduced apoptosis, promoted migration and enhanced viability of HUVECs, decreased TIPE1 (Tumor necrosis factor-α-induced protein 8-like 1) under high glucose conditions. Overexpression of TIPE1 reverses the effects of vitamin D by increasing ROS production, inflammation, cell apoptosis, and suppressing autophagy, cell migration and viability. And vitamin D negatively correlated with TIPE1 mRNA level in DM patients.

CONCLUSIONS

Vitamin D reverses the harmful effects of high glucose on HUVECs by reducing TIPE1 expression. And vitamin D supplementation could help to alleviate high glucose-induced injury in type 2 diabetes mellitus patients with microvascular complications.

Vitamin D deficiency and hyperglycemia in male rotating shift workers: A disturbed circadian rhythms influence

BACKGROUND

Shift work is related to several negative impacts on the health of workers. This study aimed to evaluate the association between vitamin D deficiency (VDD) and hyperglycemia in shift workers.

METHODOLOGY

This cross-sectional study included male rotating shift workers in an iron ore extraction company. Participants were classified as VDD when 25(OH)D < 20 ng/mL for a healthy population and 25(OH)D < 30 ng/mL for groups at risk for VDD. Hyperglycemia was classified when fasting glucose ≥100 mg/dL or HbA1c ≥ 5.7%. Data were compared using chi-square analysis with Cramer's V as effect size, and Bonferroni correction. Multivariate logistic regression, from a model of determination, was performed to investigate whether VDD was associated with hyperglycemia.

RESULTS

The study evaluated 1411 workers, most workers were aged 30-39 years (53.2%), and 77.5% self-declared as black, brown, with up to complete high school (71.4%) and working alternate shifts for more than 5 years (76.1%). Regarding glucose and vitamin D, 32.0% and 29.1% of the workers had hyperglycemia and VDD, respectively. In multivariate analysis, controlled for confounding factors, workers with VDD had a 119% increased chance of hyperglycemia (OR: 2.19; IC95%: 1.56-3.08). Furthermore, vitamin D levels in distribution quintiles showed a dose-response gradient in relation to hyperglycemia, where increased vitamin D values were associated with a reduction in the occurrence of hyperglycemia.

CONCLUSION

Rotating shift workers with vitamin D deficiency are more likely to have hyperglycemia.

Effects of Vitamin D Supplementation in Diabetic Kidney Disease: A Systematic Review

Diabetes Mellitus is a highly prevalent condition in which Diabetes Mellitus type 2 is the most common. Diabetic Kidney Disease is one of the most relevant complications and affects approximately one-third of patients with Diabetes Mellitus. It is characterized by increased urinary protein excretion and a decrease in glomerular filtration rate, assessed by serum creatinine levels. Recent studies have shown that vitamin D levels are low in these patients. This study aimed to conduct a systematic review of the effects of vitamin D supplementation on proteinuria and creatinine, which are important markers for assessing the severity of kidney disease in patients with Diabetic Kidney Disease. PUBMED, EMBASE, and COCHRANE databases were consulted, Preferred Reporting Items for a Systematic Review and Meta-Analysis guidelines were followed, and the COCHRANE toll for bias assessment was applied. Six papers were quantitative studies and fulfilled the inclusion criteria for this review. The results showed that vitamin D supplementation of 50,000 I.U./week for 8 weeks effectively reduced proteinuria and creatinine in patients with Diabetic Kidney Disease, particularly in patients with Diabetes Mellitus type 2. Vitamin D supplementation is beneficial for patients with Diabetic Kidney Disease by having essential effects on disease-related inflammatory markers, such as the reduction of proteinuria and creatinine. However, more clinical trials must be conducted to evaluate the intervention among more significant numbers of patients.

Serum and supplemental vitamin D levels and insulin resistance in T2DM populations: a meta-analysis and systematic review

Observational studies have shown a negative correlation between Vitamin D level and the likelihood of developing insulin resistance (IR) and/or diabetes over time, yet evidence remains inconsistent. In this meta-analysis and systematic review, we strive to define the potential association between serum or supplemental Vitamin D Levels and insulin resistance respectively, as well as the contribution of Vitamin D to type 2 diabetes, and to summarize the biologic plausibility of Vitamin D. Four databases (PubMed, Embase, Cochrane Library, and Web of Science) were searched for this Systematic Literature Review (SLR) to find appropriate observational studies and clinical trials published in English through to July 2022. EndNote (version X9) is used to manage the literature search results. We calculated Standard Mean Differences (SMDs) and Risk Ratios (RRs) with their 95% Confidence Intervals (CIs), separately, for continuous and dichotomous outcomes. The correlation coefficients were normalized to z values through Fisher's z-transformation to calculate the relevant statistics. Meta-analyses were carried out for all comparisons, based on a random-effects pooling model. Data analysis was performed using RevMan (version 5.3) and STATA (version 15.1). All statistical tests were two-sided, with P < 0.05 were regarded as significant. In our current meta-analysis, there are 18 RCTs and 20 observational studies including 1243 and 11,063 participants respectively. In the overall analysis, the diabetic with Vitamin D supplement treatment group showed significantly improve serum insulin (SMD =  - 0.265, 95% CI - 0.394 to - 0.136, P < 0.05), glucose (SMD =  - 0.17, 95% CI - 0.301to - 0.039, P < 0.05) and HOMA-IR (SMD =  - 0.441, 95% CI - 0.582 to - 0.3, P < 0.05) compared with the routine treatment group. Correlation analysis results showed that all three outcomes were significantly correlated in a negative manner with raised Vitamin D (insulin: r =  - 0.08 95% =  - 0.12 to - 0.04; glucose: r =  - 0.06 95% =  - 0.11 to - 0.01; HOMA-IR: r =  - 0.08 95% =  - 0.09 to - 0.06). Results of overall analysis proved that vitamin D has shown significant effect on regulates insulin resistance, and there is a significant inverse association between serum Vitamin D level and IR. Vitamin D supplementation is expected to be integrated into conventional medical approaches to prevent type 2 diabetes and to mitigate the burden of diabetes for individuals and society.PROSPERO registration number: CRD42022348295.

Associations between vitamin D levels and dietary patterns in patients with Hashimoto's thyroiditis

Introduction

Vitamin D insufficiency is a global health problem affecting healthy and diseased individuals, including patients with Hashimoto's thyroiditis (HT). Identifying dietary factors that may affect vitamin D levels and providing dietary guidelines accordingly can alleviate this problem. We therefore aimed to identify still unknown associations of dietary patterns, assessed through the Food Frequency Questionnaire (FFQ) with vitamin D blood levels.

Materials and methods

FFQ was collected from 459 patients from Croatian Biobank of Patients with Hashimoto's thyroiditis (CROHT), while total 25(OH)D was measured from their stored serum samples. We performed linear regression analysis between vitamin D levels and weekly intake of 24 food groups in 459 patients with HT (ALL), and in two disease-severity groups (MILD and OVERT).

Results

The main results of our study are observations of: (1) an inverse association between vitamin D levels and coffee consumption (ALL: β = -0.433, p = 0.005; OVERT: β = -0.62, p = 0.008); (2) an inverse association between vitamin D levels and sweets consumption (ALL: β = -0.195, p = 0.034; OVERT: β = -0.431, p = 0.006); (3) positive association between vitamin D levels and vegetable consumption (ALL: β = 0.182, p = 0.019; OVERT, β = 0.311, p = 0.009). Importantly, effect sizes of all three associations were more prominent in HT patients with prolonged and more severe disease (OVERT).

Conclusion

Further research into the functional and causal relationships of the observed associations is important to provide guidance regarding coffee/sugar intake on vitamin D status. A well-balanced diet can help prevent vitamin D deficiency and improve the quality of life of patients with HT, especially those in later stages of disease characterized by greater metabolic imbalance.

Comparison of insulin resistance-associated parameters in US adults: a cross-sectional study

BACKGROUND

Triglyceride-glucose (TyG) is correlated with cardiovascular events caused by insulin resistance (IR). The aim of this study was to analyze the relationship between TyG and its related indicators and IR among US adults from 2007 to 2018 in the National Health and Nutrition Examination Survey (NHANES) database so as to identify more accurate and reliable predictors of IR.

METHODS

This is a cross-sectional study including 9884 participants (2255 with IR and 7629 without IR). TyG, TyG-body mass index (TyG-BMI), TyG waist circumference (TyG-WC), and TyG waist-to-height ratio (TyG-WtHR) were measured using standard formulas.

RESULTS

TyG, TyG-BMI, TyG-WC, and TyG-WtHR were significantly correlated with IR in the general population, with TyG-WC being the most strongly correlated, with an odds ratio of 8.00 (95% confidence interval 5.05-12.67) for the fourth quartile of TyG-WC compared with the first quartile in the adjusted model. Receiver operating characteristic (ROC) analysis of the participants showed that the maximum area under the TyG-WC curve was 0.8491, which was significantly higher than that of the other three indicators. Moreover, this trend was stable both among people of both genders and among patients with coronary heart disease (CHD), hypertension, and diabetes.

CONCLUSIONS

The present study confirms that the TyG-WC index is more successful than TyG alone in identifying IR. In addition, our findings demonstrate that TyG-WC is a simple and effective marker for screening the general US adult population and those with CHD, hypertension, and diabetes and can be effectively used in clinical practice.

Association of serum 25-hydroxyvitamin D with metabolic disturbances in adolescents

OBJECTIVES

Data concerning the association of vitamin D with metabolic disturbances in adolescents are contradictory. The aim of this study was to identify metabolic abnormalities in adolescents with 25-hydroxyvitamin D (25[OH]D) deficiency and to determine informative indices for the early detection of these metabolic disturbances.

METHODS

A cross-sectional observational study including 90 adolescents aged 13-15 years was carried out during the winter. Anthropometric measures were collected. Fasting blood samples were assessed for the following parameters: serum 25(OH)D, lipids, and glucose.

RESULTS

The majority of the study adolescents had low 25(OH)D concentration. The prevalence of 25(OH)D deficiency (<12 ng/ml) and insufficiency (12-20 ng/ml) in adolescents was 34.4% and 55.6%, respectively. Among the metabolic disturbance, hypo-high-density lipoprotein cholesterolemia prevailed in the adolescents, while hypercholesterolemia, hypertriglyceridemia, and hyperglycemia were rare. 25(OH)D status showed an association with the metabolic score for insulin resistance (METS-IR, r = -0.40; p < .001), high-density lipoprotein cholesterol level (r = 0.31; p = .003), atherogenic index of plasma (r = -0.30; p = .004) and body mass index (r = -0.23, p = .032). There were no significant correlations between 25(OH)D level and other lipid or glucose levels. The degree of hypovitaminosis D affects METS-IR values.

CONCLUSIONS

25(OH)D deficiency in the studied adolescents had not yet manifested serious metabolic diseases. Of all the analyzed parameters, METS-IR was most strongly associated with 25(OH)D level and can be considered a useful marker of early metabolic disturbances in adolescents with 25(OH)D deficiency.

Association between vitamin D and insulin resistance in adults with latent tuberculosis infection: Results from the National Health and Nutrition Examination Survey (NHANES) 2011-2012

BACKGROUND

Evidence demonstrated that vitamin D insufficiency was involved in insulin resistance (IR) pathogenesis and associated with tuberculosis. However, the association of vitamin D and IR in patients with latent tuberculosis infection (LTBI) remains unclear. This study aims to evaluate the association between vitamin D and insulin resistance in US adults with LTBI.

METHOD

National Health and Nutrition Examination Survey (NHANES) participants ≥ 20 years during the years 2011-2012 with positive QuantiFERON®-TB Gold-In-Tube (QFT) or tuberculin skin testing (TST) were enrolled in present study. Participants with LTBI were divided into 2 groups: (1) vitamin D insufficiency group (n = 267), and (2) vitamin D sufficiency group (n = 437).

RESULTS

Weighted analysis of all the population in the study showed that serum 25(OH)D inversely correlated with HOMA-IR (r = -0.14, P = 0.008). The vitamin D insufficiency group had higher fasting insulin (17.5 (1.38) vs. 15.29 (3.1), respectively, P = 0.0013) and HOMA-IR (5.0 (0.4) vs. 4.5 (1), respectively, P = 0.013) than the vitamin D sufficiency group. In adjusted analysis, vitamin D levels was independently associated with insulin resistance (adjusted OR [aOR] 2.74; 95% CI, 1.01-7.48, p = 0.0489).

CONCLUSIONS

Taken together, our study suggested that serum 25(OH) D concentrations were inversely and independently associated with HOMA-IR in LTBI.

Serum, Dietary, and Supplemental Vitamin D Levels and Insulin Resistance in 6294 Randomly Selected, Non-Diabetic U.S. Adults

The primary aim of this study was to determine the associations between serum, dietary, and supplemental vitamin D levels and insulin resistance in 6294 non-diabetic U.S. adults. A total of 8 years of data from the 2011−2018 National Health and Nutrition Examination Survey (NHANES) and a cross-sectional design were utilized to answer the research questions. Serum vitamin D levels were quantified using high-performance liquid chromatography−tandem mass spectrometry. Dietary and supplemental vitamin D intakes were assessed using the average of two 24 h dietary recalls taken 3−10 days apart. The homeostatic model assessment (HOMA), based on fasting glucose and fasting insulin levels, was employed to index insulin resistance. Demographic covariates were age, sex, race, and year of assessment. Differences in physical activity, body mass index (BMI), cigarette smoking, body weight, season, and energy intake were also controlled statistically. Serum levels of vitamin D differed significantly, and in a dose−response order, across quartiles of HOMA-IR, after adjusting for year, age, sex, and race (F = 30.3, p < 0.0001) and with all the covariates controlled (F = 5.4, p = 0.0029). Dietary vitamin D levels differed similarly across HOMA-IR quartiles, but to a lesser extent, respectively (F = 8.1, p = 0.0001; F = 2.9, p = 0.0437). Likewise, supplemental vitamin D levels also differed across the HOMA-IR quartiles, respectively (F = 3.5, p = 0.0205; F = 3.3, p = 0.0272). With all the covariates controlled, the odds of having insulin resistance were significantly greater for those in the lowest quartile of serum and supplemental vitamin D intake compared to the other quartiles combined. In conclusion, in this nationally representative sample, serum, dietary, and supplemental vitamin D were each predictive of insulin resistance, especially in those with low serum levels and those with no supplemental intake of vitamin D.

Vitamin D in Osteosarcopenic Obesity

Osteosarcopenic obesity is a unique clinical condition where low bone and muscle mass coexist in individuals with obesity. Alterations in adipose tissue, skeletal muscle and bone are strictly interconnected, and vitamin D plays key roles in several metabolic pathways that are involved in maintaining musculoskeletal health and glucose homeostasis. We reviewed the available literature on mechanisms underlying osteosarcopenic obesity, with a focus on the role of vitamin D in the pathogenesis and treatment of the condition. We found that, although evidence from large observational studies and pre-clinical experiments strongly supports a role of vitamin D deficiency in the pathogenesis of osteosarcopenic obesity, the common belief that vitamin D improves musculoskeletal health lacks solid clinical evidence, as trials specifically aimed at assessing the effects of vitamin D supplementation in patients with osteosarcopenic obesity are not available, and trials that investigated the role of vitamin D on muscle and bone health in other patient populations either showed no or even detrimental effects. We conclude that large observational and interventional studies including individuals with osteosarcopenic obesity representative of different sex, age and race are needed to better define the role of vitamin D in the pathogenesis and treatment of this condition.

Comparative Effect of Vitamin D3 and Carbenoxolone Treatments in Metabolic Syndrome Rats

Metabolic syndrome (MetS) is a cluster of cardiovascular risk factors including central obesity, hypertension, insulin resistance, dyslipidemia, and hyperglyemia. MetS is found to be a positive predictor of cardiovascular morbidity and mortality. The present study was planned to test the efficacy of vitamin D3 supplementation as compared to cortisol inhibition on MetS parameters. Wistar rats were allocated into four groups: controls, untreated MetS, and MetS treated with either vitamin D3 (10 μg/kg), or carbenoxolone (50 mg/kg). MetS was induced by combination of high fat diet and oral fructose. After the induction period (8 weeks), MetS was confirmed and treatment modalities started for a further 4 weeks. Compared to untreated MetS, vitamin D3 and carbenoxolone treated rats showed significant reduction in blood pressure, body mass index, lee index, waist circumference, retroperitoneal fat, and improvement of dyslipidemia. Meanwhile, treatment with carbenoxolone significantly lowered the elevated liver enzymes, vitamin D3 resulted in improved insulin sensitivity, enhanced glucose uptake by muscles and replenished glycogen content in the liver and muscles near control levels. In conclusion, although treatment with vitamin D3 or carbenoxolone reduced the risk factors associated with MetS, vitamin D3 was effective in ameliorating insulin resistance which is the hallmark of MetS.