Association of serum 25-hydroxyvitamin D3 with adipokines and inflammatory marker in persons with prediabetes mellitus

An Overview of Different Vitamin D Compounds in the Setting of Adiposity

A large body of research shows an association between higher body weight and low vitamin D status, as assessed using serum 25-hydroxyvitamin D concentrations. Vitamin D can be metabolised in adipose tissue and has been reported to influence gene expression and modulate inflammation and adipose tissue metabolism in vitro. However, the exact metabolism of vitamin D in adipose tissue is currently unknown. White adipose tissue expresses the vitamin D receptor and hydroxylase enzymes, substantially involved in vitamin D metabolism and efficacy. The distribution and concentrations of the generated vitamin D compounds in adipose tissue, however, are largely unknown. Closing this knowledge gap could help to understand whether the different vitamin D compounds have specific health effects in the setting of adiposity. This review summarises the current evidence for a role of vitamin D in adipose tissue and discusses options to accurately measure vitamin D compounds in adipose tissue using liquid chromatography tandem mass spectrometry (LC/MS-MS).

The Association between Serum 25-Hydroxyvitamin D3 Levels and Pro-Inflammatory Markers in New-Onset Type 2 Diabetes Mellitus and Prediabetes

In this study, we aimed to reveal the pro-inflammatory effects of serum 25-hydroxyvitamin D3 (Vit D) deficiency and insufficiency in new-onset type 2 diabetes mellitus (T2DM) and prediabetes. We recruited 84 prediabetes patients, 94 new-onset T2DM patients and 113 healthy participants. We measured the levels of C-reactive protein (CRP), fibrinogen, ferritin, interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) in the serum of the participants. ANOVA Bonferroni and Kruskal-Wallis Dunn tests were used to compare the inflammation markers and vitamin D levels between the groups. Based on covariance analysis with age, gender and BMI, the Vit D levels of the T2DM group were significantly lower (p < 0.003). Pro-inflammatory markers and CRP were significantly higher in prediabetic and diabetic subjects. In the prediabetes group, IL-1β, IL-6, IL-8, TNF-α and MAPK were significantly higher in those with Vit D insufficiency and deficiency groups. In the T2DM group, IL-1β, IL-6, IL-8, TNF-α, NF-κB, MAPK and CRP were significantly higher in those with Vit D insufficiency and deficiency. Our study emphasizes the pro-inflammatory effects of Vit D deficiency and insufficiency in new-onset type 2 diabetes mellitus and prediabetes.

Association Between Serum 25-hydroxyvitamin D Concentrations and Mortality Among Adults With Prediabetes

OBJECTIVES

To investigate the association of circulating 25-hydroxyvitamin D [25(OH)D] levels with mortality among adults with prediabetes.

METHODS

This retrospective cohort study included 15,195 adults with prediabetes (aged ≥20 years) from the National Health and Nutrition Examination Survey (NHANES) III and NHANES 2001-2014. Mortality from all causes, cardiovascular disease (CVD), and cancer was linked to National Death Index mortality data.

RESULTS

The median (interquartile range) concentration of serum 25(OH)D was 60.5 (45.3, 77.4) nmol/L, and only 23.1% had sufficient vitamin D (≥75 nmol/L). Elevated serum 25(OH)D concentrations were significantly associated with lower levels of insulin, homeostasis model assessment of insulin resistance, triglyceride, and C-reactive protein, and higher levels of high-density lipoprotein at baseline (all Ptrend < 0.05). During a median follow up of 10.7 years, 3765 deaths (including 1080 CVD deaths and 863 cancer deaths) were identified. Compared with participants with 25(OH)D <30 nmol/L, the multivariate-adjusted hazard ratios and 95% confidence intervals for participants with 25(OH)D ≥ 75 nmol/L were 0.66 (0.53, 0.82) for all-cause mortality (Ptrend < 0.001), 0.66 (0.48, 0.89) for CVD mortality (Ptrend = 0.001), and 0.82 (0.49, 1.35) for cancer mortality (Ptrend = 0.32). For per-unit increment in ln-transformed 25(OH)D, there was a 27% lower risk of all-cause mortality and a 34% lower risk of CVD mortality (both P < 0.01).

CONCLUSIONS

These findings suggested that higher serum 25(OH)D concentrations were associated with lower all-cause and CVD mortality among individuals with prediabetes.

Low 25-hydroxyvitamin D is associated with arterial stiffness in Chinese with Type 2 diabetes mellitus

OBJECTIVES

Arterial stiffness (AS), one of the complications of diabetes, associated with many metabolic factors. This study aimed to investigate the association between 25-hydroxyvitamin D(25(OH)D) and AS in type 2 diabetes mellitus (T2DM).

METHODS

We identified 1335 diabetic patients from the Department of Endocrinology, Shanghai Tenth People's Hospital. Finally, 603 T2DM patients were included in the study. They were divided into two groups: AS group (baPWV ≥ 15,500 cm/s) and the control group (baPWV < 1550 cm/s).

RESULTS

(1) Heart rate (HR) and systolic pressure (SBP) were higher while body weight and body mass index (BMI) were smaller in AS group than the control group (all P < 0.05). (2) Compared to patients without AS, patients with AS showed lower 25(OH)D and higher rate of 25(OH)D deficiency (42 ± 16 vs. 45 ± 17 mol/l, 68% vs. 64%, all P < 0.05). (3) BaPWV was negatively associated with 25(OH)D (r = -0.12, P = 0.004), while positively associated with age, duration of diabetes, HR, SBP, and low-density lipoprotein cholesterol and negatively associated with body weight and BMI (all P < 0.05). (4) Multiple linear regression showed that 25(OH)D was the negatively influencing factor of baPWV (β = -2.2, P = 0.01). Logistic regression showed that age and SBP were risk factor of AS (OR:1.07, 95% CI: 1.05-1.10, P < 0.001; OR:1.03, 95% CI: 1.02-1.04, P < 0.001) while 25(OH)D was protective factor of AS (OR:0.987, 95% CI: 0.976-0.998, P = 0.024).

CONCLUSIONS

T2DM patients with AS had lower 25(OH)D and higher rate of 25(OH)D deficiency. There was a negative relationship between 25(OH)D and AS assessed by baPWV.

Can Optimum Solar Radiation Exposure or Supplemented Vitamin D Intake Reduce the Severity of COVID-19 Symptoms?

The foremost mortality-causing symptom associated with COVID-19 is acute respiratory distress syndrome (ARDS). A significant correlation has been identified between the deficiency in vitamin D and the risk of developing ARDS. It has been suggested that if we can reduce or modify ARDS in COVID-19 patients, we may significantly reduce the severity of COVID-19 symptoms and associated mortality rates. The increased mortality of dark-skinned people, who have a reduced UV absorption capacity, may be consistent with diminished vitamin D status. The factors associated with COVID-19 mortality, such as old age, ethnicity, obesity, hypertension, cardiovascular diseases, and diabetes, are all found to be linked with vitamin D deficiency. Based on this review and as a precautionary measure, it is suggested that the adoption of appropriate and safe solar exposure and vitamin D enriched foods and supplements should be considered to reduce the possible severity of COVID-19 symptoms. Safe sun exposure is deemed beneficial globally, specifically in low and middle-income countries, as there is no cost involved. It is also noted that improved solar exposure and vitamin D levels can reduce the impact of other diseases as well, thus assisting in maintaining general human well-being.

Relationships Between Vitamin D Status and Cytokine: Results from Interferon-Based Therapy in Non-Cirrhotic, Treatment-Naïve Patients with Chronic Hepatitis C Infection

Background

Vitamin D contributes to bone health and extra-skeletal effects. The mechanisms underlying vitamin D metabolism have not been extensively evaluated. The relationships between vitamin D and inflammatory cytokines are debated. Our objective was to investigate whether supplemental interferons are associated with longitudinal change of vitamin D status in humans.

Methods

A total of 48 patients with 24 or 48 weeks of pegylated interferon-α plus ribavirin therapy were examined for serum 25-hydroxyvitamin D (25[OH]D) level before treatment, at the end of treatment, and 24 weeks after treatment. In addition, we analyzed publicly available RNA sequencing data from accession GSE42697 and GSE7123 in the Gene Expression Omnibus.

Findings

The overall sustained virologic response (SVR) rate was 62.5%. There was no statistically significant association between baseline 25(OH)D concentrations and liver fibrosis. In patients with SVR, serum 25(OH)D increased markedly at end-of-treatment and decreased markedly by the end of the 24-week follow-up period. In the non-SVR group, this treatment-dependent change was lost. In gene expression analysis, the vitamin D biosynthesis process was activated in subjects with SVR, but not in patients without SVR. Furthermore, vitamin D receptor (VDR) signaling in peripheral blood mononuclear cells (PBMCs) was triggered in marked responders but not in poor responders.

Conclusion

In the aggregate, these data suggest that interferons have a regulatory influence on vitamin D status that can contribute to VDR signaling in PBMCs.

Is the shielding effect of cholecalciferol in SARS CoV-2 infection dependable? An evidence based unraveling

Despite being announced as a global health concern and emergency in January by WHO, designing specific treatment for SARS-CoV-2 is still a summit yet to be conquered. Currently, many drugs are being tested in the clinical scenario and vitamins play a significant role in therapeutic management. Based on the available evidence, we postulate that maintaining normal vitamin D₃ levels may reduce severity, mortality risk of COVID-19. This review elucidates the alarming need for randomized clinical trials to determine the role of vitamin D in patient prognosis in COVID-19 infection and on latitude bases epidemiological outcome.

Novel coronavirus infection SARS-CoV-2 in elderly and senile patients: prevention, diagnosis and treatment. Expert Position Paper of the Russian Association of Gerontology and Geriatrics

A novel coronavirus infection SARS-CoV-2 (COVID19) is especially dangerous for elderly and senile patients. Preventive measures for elderly people should cover three areas: 1) direct prevention of the viral infection, 2) preservation of the functional status and prevention of geriatric syndromes, including the use of social support measures, 3) control of comorbidities. The clinical pattern of COVID-19 in older patients may be atypical, while the mildness of symptoms (no fever, cough, shortness of breath) may not correspond to the severity of the prognosis. Delirium may be the first manifestation of COVID-19, which requires special care in its screening. Management of elderly and senile patients with COVID19 should include measures for delirium prevention, the detection and improvement of nutrition. The risk of malnutrition with sarcopenia increases with hospitalization of a patient, especially when using artificial ventilation, is associated with an unfavorable prognosis during hospitalization, accelerates the progression of senile asthenia and reduces the quality of life. Geriatric assessment is the cornerstone of determining the management of an elderly patient.

Cutoff point estimation for serum vitamin D concentrations to predict cardiometabolic risk in Brazilian children

BACKGROUND/OBJECTIVES

To evaluate serum 25(OH)D concentrations and determine a cutoff point for cardiometabolic risk in children.

SUBJECT/METHODS

This is a cross-sectional study with a representative sample of 378 8-9-year-old children from all urban schools in the city of Viçosa, MG, Brazil. Sociodemographic data and information on lifestyle, and food consumption were collected. Biochemical evaluation included glucose, triglycerides, leptin, calcidiol [25(OH)D], and parathormone. Body composition was assessed by dual energy X-ray absorptiometry. Cardiometabolic risk was considered when nontraditional risk markers were detected, including triglyceride × glycemia index (TyG index), hyperleptinemia, and hypertriglyceridemic waist phenotype (HWP). The receiver operating characteristic curve (ROC) was used to define the cutoff point for serum 25(OH)D to predict cardiometabolic risk.

RESULTS

25(OH)D showed better predictive capacity for grouping of cardiometabolic risk markers than for either single or paired markers. The area under the curve for grouping of risk markers was 0.636 (95% CI: 0.585, 0.685, P < 0.001). The cutoff point to predict cardiometabolic risk was defined as 32.0 ng/mL.

CONCLUSION

25(OH)D presented good predictive capacity for cardiometabolic risk and 25(OH)D concentration higher than 32 ng/mL was associated with a 49% reduction of cardiometabolic risk prevalence in prepubertal Brazilian children.

Evidence that Vitamin D Supplementation Could Reduce Risk of Influenza and COVID-19 Infections and Deaths

The world is in the grip of the COVID-19 pandemic. Public health measures that can reduce the risk of infection and death in addition to quarantines are desperately needed. This article reviews the roles of vitamin D in reducing the risk of respiratory tract infections, knowledge about the epidemiology of influenza and COVID-19, and how vitamin D supplementation might be a useful measure to reduce risk. Through several mechanisms, vitamin D can reduce risk of infections. Those mechanisms include inducing cathelicidins and defensins that can lower viral replication rates and reducing concentrations of pro-inflammatory cytokines that produce the inflammation that injures the lining of the lungs, leading to pneumonia, as well as increasing concentrations of anti-inflammatory cytokines. Several observational studies and clinical trials reported that vitamin D supplementation reduced the risk of influenza, whereas others did not. Evidence supporting the role of vitamin D in reducing risk of COVID-19 includes that the outbreak occurred in winter, a time when 25-hydroxyvitamin D (25(OH)D) concentrations are lowest; that the number of cases in the Southern Hemisphere near the end of summer are low; that vitamin D deficiency has been found to contribute to acute respiratory distress syndrome; and that case-fatality rates increase with age and with chronic disease comorbidity, both of which are associated with lower 25(OH)D concentration. To reduce the risk of infection, it is recommended that people at risk of influenza and/or COVID-19 consider taking 10,000 IU/d of vitamin D₃ for a few weeks to rapidly raise 25(OH)D concentrations, followed by 5000 IU/d. The goal should be to raise 25(OH)D concentrations above 40-60 ng/mL (100-150 nmol/L). For treatment of people who become infected with COVID-19, higher vitamin D₃ doses might be useful. Randomized controlled trials and large population studies should be conducted to evaluate these recommendations.

Evidence that Vitamin D Supplementation Could Reduce Risk of Influenza and COVID-19 Infections and Deaths

The world is in the grip of the COVID-19 pandemic. Public health measures that can reduce the risk of infection and death in addition to quarantines are desperately needed. This article reviews the roles of vitamin D in reducing the risk of respiratory tract infections, knowledge about the epidemiology of influenza and COVID-19, and how vitamin D supplementation might be a useful measure to reduce risk. Through several mechanisms, vitamin D can reduce risk of infections. Those mechanisms include inducing cathelicidins and defensins that can lower viral replication rates and reducing concentrations of pro-inflammatory cytokines that produce the inflammation that injures the lining of the lungs, leading to pneumonia, as well as increasing concentrations of anti-inflammatory cytokines. Several observational studies and clinical trials reported that vitamin D supplementation reduced the risk of influenza, whereas others did not. Evidence supporting the role of vitamin D in reducing risk of COVID-19 includes that the outbreak occurred in winter, a time when 25-hydroxyvitamin D (25(OH)D) concentrations are lowest; that the number of cases in the Southern Hemisphere near the end of summer are low; that vitamin D deficiency has been found to contribute to acute respiratory distress syndrome; and that case-fatality rates increase with age and with chronic disease comorbidity, both of which are associated with lower 25(OH)D concentration. To reduce the risk of infection, it is recommended that people at risk of influenza and/or COVID-19 consider taking 10,000 IU/d of vitamin D₃ for a few weeks to rapidly raise 25(OH)D concentrations, followed by 5000 IU/d. The goal should be to raise 25(OH)D concentrations above 40-60 ng/mL (100-150 nmol/L). For treatment of people who become infected with COVID-19, higher vitamin D₃ doses might be useful. Randomized controlled trials and large population studies should be conducted to evaluate these recommendations.

Vitamin D supplementation increases adipokine concentrations in overweight or obese adults

PURPOSE

Vitamin D regulates adipokine production in vitro; however, clinical trials have been inconclusive. We conducted secondary analyses of a randomized controlled trial to examine whether vitamin D supplementation improves adipokine concentrations in overweight/obese and vitamin D-deficient adults.

METHODS

Sixty-five individuals with a BMI ≥ 25 kg/m² and 25-hydroxyvitamin D (25(OH)D) ≤ 50 nmol/L were randomized to oral cholecalciferol (100,000 IU single bolus followed by 4,000 IU daily) or matching placebo for 16 weeks. We measured BMI, waist-to-hip ratio, % body fat (dual X-ray absorptiometry), serum 25(OH)D (chemiluminescent immunoassay) and total adiponectin, leptin, resistin, and adipsin concentrations (multiplex assay; flow cytometry). Sun exposure, physical activity, and diet were assessed using questionnaires.

RESULTS

Fifty-four participants completed the study (35M/19F; mean age = 31.9 ± 8.5 years; BMI = 30.9 ± 4.4 kg/m²). After 16 weeks, vitamin D supplementation increased 25(OH)D concentrations compared with placebo (57.0 ± 21.3 versus 1.9 ± 15.1 nmol/L, p < 0.001). There were no differences between groups for changes in adiponectin, leptin, resistin, or adipsin in unadjusted analyses (all p > 0.05). After adjustment for baseline values, season, sun exposure, and dietary vitamin D intake, there was a greater increase in adiponectin (β[95%CI] = 13.7[2.0, 25.5], p = 0.02) and leptin (β[95%CI] = 22.3[3.8, 40.9], p = 0.02) in the vitamin D group compared with placebo. Results remained significant after additional adjustment for age, sex, and % body fat (p < 0.02).

CONCLUSIONS

Vitamin D may increase adiponectin and leptin concentrations in overweight/obese and vitamin D-deficient adults. Further studies are needed to clarify the molecular interactions between vitamin D and adipokines and the clinical implications of these interactions in the context of obesity.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov: NCT02112721.

Sex-Specific Association of Serum 25-Hydroxyvitamin D3 with Insulin Resistance in Chinese Han Patients with Newly Diagnosed Type 2 Diabetes Mellitus

This study aimed to explore the association between serum 25-hydroxyvitamin D (25(OH)D) and insulin resistance as well as β-cell function in Chinese Han patients with newly diagnosed type 2 diabetes mellitus (T2DM). A total of 264 patients was included in this study. Serum 25(OH)D, plasma glucose, serum insulin and other biochemical parameters were assayed. Postprandial venous blood was collected after a mixed-nutrient load. Insulin resistance was assessed by the homeostasis model assessment for insulin resistance (HOMA-IR) and Matsuda insulin sensitivity index (Matsuda ISI). The β-cell function was assessed by the homeostasis model assessment for insulin secretion (HOMA-β) and the change in insulin divided by change in glucose from 0 to 30 min (ΔI_0-30/ΔG_0-30). Patients were divided into three groups according to tertiles of serum 25(OH)D levels. There were significant differences in HOMA-IR and Matsuda ISI among the three groups (HOMA-IR, p=0.005; Matsuda ISI, p=0.009). Pearson correlation analyses showed that serum 25(OH)D was negatively correlated with fasting serum insulin (FIns) (r=-0.209, p=0.012) and HOMA-IR (r=-0.273, p=0.001), and positively correlated with Matsuda ISI (r=0.219, p=0.009) only in the male population. Multiple stepwise regression analyses showed that in the male population, serum 25(OH)D was an independent predictor for both HOMA-IR and Matsuda ISI before and after adjustment for confounding factors, respectively (p<0.05 for both). This study indicates the association of vitamin D with insulin resistance in male patients with newly diagnosed T2DM, which may contribute to the understanding of the mechanism underlying the onset of T2DM in the Chinese Han population.

Role of vitamin D in pregnancy and Toll-like receptor pathway

There is a growing concern about the impacts of hypovitaminosis D on the health of pregnant woman, fetal development, childhood, and adult life. Variations in maternal nutrition during gestation and/or lactation play a critical role in the physiological and metabolic development of the fetus and neonate, which can induce phenotypic changes and trigger important consequences throughout life, such as type 2 diabetes, cardiovascular disease, obesity, and hypertension. Vitamin D plays a role in regulating cell proliferation and differentiation and in modulating the innate and adaptive immune response. Also, vitamin D correlates with changes in cytokines, anti and proinflammatory, as well as prevents inflammation induced by changes in myometrial cells mediated by the nuclear factor kappa B pathway. Further investigation is required regarding these relationship.