The relationship between serum 25-hydroxy vitamin D concentration and obesity in type 2 diabetic patients and healthy subjects

Evaluation of the relationship of cytokines concentrations tumor necrosis factor-alpha, interleukin-6, and C-reactive protein in obese diabetics and obese non-diabetics: A comparative study

Obesity has been linked to a low-grade inflammatory process in the white adipose tissue. Our study aims to detect the relationship between cytokine levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and C-reactive protein (CRP) in obese diabetics, compared to obese non-diabetics, Iraqi individuals. Ninety Iraqi adults, 45 type 2 diabetic and 45 non-diabetic obese, were selected as controls. Serum levels of TNF-α, IL-6, CRP, homeostatic model assessment for homeostasis model assessment of insulin resistance (HOMA-IR), body fat, and body mass index (BMI) were measured. The concentration of TNF-α, IL-6, and CRP were significantly greater in the obese diabetics, compared to the obese non-diabetics. BMI was significantly positively correlated with the concentration of TNF-α, IL-6, and CRP in the two groups. At the same time, HOMA-IR was non-significantly positively associated with them in obese diabetics. In contrast, the correlation was significantly positive between HOMA-IR with TNF-a, IL-6, and CRP in the obese non-diabetics group. Obese diabetics have more inflammation than obese non-diabetics as evidenced by the former's higher levels of TNF-α and IL-6. Obesity-related imbalances disrupt metabolic processes and increase CRP, TNF-, and IL-6 levels. Therefore, IR is promoted by the increase of cytokines.

Neutrophilia and its correlation with increased inflammatory response in COVID-19 in diabetic and pre-diabetic patients

Background: Hyperglycemic patients are at a high risk of COVID-19 severity. Neutrophils have been considered critical effector cells in COVID-19 development. Vitamin D deficiency is prevalent in hyperglycemic patients and was found to adversely associate with the neutrophil count.

Aim: The goal of this work was to evaluate the characteristics of diabetic and pre-diabetic COVID-19 patients and discovered changes in neutrophils and their correlation, if any, with disease clinical presentation.

Patients and Methods: The study included total of (514) Covid-19 positive patients confirmed by PCR and recruited from the Prince Mohammad Bin Abdulaziz Hospital in Riyadh, Saudi Arabia. Patient’s clinical characteristics were collected for all patients. Laboratory tests include HbA1c, neutrophil count, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), ferritin, D- dimer, 25 hydroxy vitamin D (25(OH)D), and folate.

Results: The results found that 286 patients (55.6%) were diabetic, 77 patients (15%) were pre-diabetic and 151 (29.4%) were normoglycaemic. A significant difference was exhibited regarding the neutrophil count and inflammatory factors of COVID-19 severity. Furthermore, the neutrophil count was found to be directly correlated with the severity monitoring biochemical markers for Covid-19: CRP, ESR, ferritin, and D-dimer and inversely associated with vitamin D levels in diabetic and pre-diabetic patients.

Conclusion: Our findings highlight the change of neutrophils in COVID-19 diabetic and pre-diabetic patients that was found to correlate positively with CRP, ESR, ferritin, and D-dimer, and negatively with 25(OH)D, but their correlation with the clinical presentation of the disease need further large investigations.

The Role of Vitamin D and Its Molecular Bases in Insulin Resistance, Diabetes, Metabolic Syndrome, and Cardiovascular Disease: State of the Art

In the last decade, an increasing awareness was directed to the role of Vitamin D in non-skeletal and preventive roles for chronic diseases. Vitamin D is an essential hormone in regulating calcium/phosphorous balance and in the pathogenesis of inflammation, insulin resistance, and obesity. The main forms of vitamin D, Cholecalciferol (Vitamin D3) and Ergocalciferol (Vitamin D2) are converted into the active form (1,25-dihydroxyvitamin D) thanks to two hydroxylations in the liver, kidney, pancreas, and immune cells. Some anti-inflammatory cytokines are produced at higher levels by vitamin D, while some pro-inflammatory cytokines are released at lower levels. Toll-Like Receptor (TLR) expression is increased, and a pro-inflammatory state is also linked to low levels of vitamin D. Regardless of how it affects inflammation, various pathways suggest that vitamin D directly improves insulin sensitivity and secretion. The level of vitamin D in the body may change the ratio of pro- to anti-inflammatory cytokines, which would impact insulin action, lipid metabolism, and the development and function of adipose tissue. Many studies have demonstrated an inverse relationship between vitamin D concentrations and pro-inflammatory markers, insulin resistance, glucose intolerance, metabolic syndrome, obesity, and cardiovascular disease. It is interesting to note that several long-term studies also revealed an inverse correlation between vitamin D levels and the occurrence of diabetes mellitus. Vitamin D supplementation in people has controversial effects. While some studies demonstrated improvements in insulin sensitivity, glucose, and lipid metabolism, others revealed no significant effect on glycemic homeostasis and inflammation. This review aims to provide insight into the molecular basis of the relationship between vitamin D, insulin resistance, metabolic syndrome, type 1 and 2 diabetes, gestational diabetes, and cardiovascular diseases.

Association of Vitamin D Genetic Risk Score with Noncommunicable Diseases: A Systematic Review

Background and Aims: The genetic risk score (GRS) is an important tool for estimating the total genetic contribution or susceptibility to a certain outcome of interest in an individual, taking into account their genetic risk alleles. This study aims to systematically review the association between the GRS of low vitamin D with different noncommunicable diseases/markers. Methods: The article was first registered in PROSPERO CRD42023406929. PubMed and Embase were searched from the time of inception until March 2023 to capture all the literature related to the vitamin D genetic risk score (vD-GRS) in association with noncommunicable diseases. This was performed using comprehensive search terms including "Genetic Risk Score" OR "Genetics risk assessment" OR "Genome-wide risk score" AND "Vitamin D" OR 25(HO)D OR "25-hydroxyvitamin D". Results: Eleven eligible studies were included in this study. Three studies reported a significant association between vD-GRS and metabolic parameters, including body fat percentage, body mass index, glycated hemoglobin, and fasting blood glucose. Moreover, colorectal cancer overall mortality and the risk of developing arterial fibrillation were also found to be associated with genetically deprived vitamin D levels. Conclusions: This systematic review highlights the genetic contribution of low-vitamin-D-risk single nucleotides polymorphisms (SNPs) as an accumulative factor associated with different non-communicable diseases/markers, including cancer mortality and the risk of developing obesity, type 2 diabetes, and cardiovascular diseases such as arterial fibrillation.

Circulating 25-hydroxyvitamin D is associated with metabolic phenotypes of obesity: National Food and Nutrition Surveillance

Different phenotypes of obesity are each related with different complications and comorbidities. We hypothesized that suboptimal vitamin D status is directly associated with an unhealthy metabolic status, especially if allied with obesity. This cross-sectional study was performed in the framework of the National Food and Nutrition Surveillance. Overall, 1098 men and women participated in this study. In addition to height and weight, serum concentrations of 25-hydroxyvitamin D (25(OH)D) and glycemic and lipidemic status were evaluated. Then participants were classified into 4 groups based on body mass index and lipidemic and glycemic profile status, as follows: hyperglycemic-dyslipidemic obese (HDO), hyperglycemic-dyslipidemic nonobese (HDNO), normoglycemic-normolipidemic obese (NNO), and normoglycemic-normolipidemic nonobese (NNNO). In this study, 31.6% of participants were classified as HDO, 7.5% as HDNO, 34.5% as NNO, and 26.4% as NNNO. The frequency of suboptimal vitamin D status was more prevalent in HDO (81.8%) than in other phenotypes (HDNO, 80%; NNO, 77.6%; NNNO, 73.8%; P = .015). In the multivariate model, suboptimal vitamin D status significantly increased the odds of being NNO (odds ratio [OR], 1.28; 95% CI, 0.84-1.95), HDNO (OR, 1.48; 95% CI, 0.77-2.83), and HDO (OR, 1.73; 95% CI, 1.11-2.7) compared with the NNNO group. Likewise, in multivariate model, per each unit (ng/mL) increment in 25(OH)D concentration, the odds of HDNO and HDO decreased significantly by 4% (OR, 0.96; 95% CI, 0.94-0.98) and 7% (OR, 0.93; 95% CI, 0.92-0.95), respectively. The results of the study showed a significant relationship between serum 25(OH)D concentrations and metabolic obesity phenotypes; these data confirm the association between suboptimal vitamin D status and metabolic complications, especially in obese individuals.

Consumption of Dairy Products and the Risk of Overweight or Obesity, Hypertension, and Type 2 Diabetes Mellitus: A Dose-Response Meta-Analysis and Systematic Review of Cohort Studies

Dairy products have been suggested to be related to the prevention of overweight or obesity, hypertension, and type 2 diabetes mellitus (T2DM). These associations are currently controversial, however, and a systematic quantitative meta-analysis is lacking. In this study, we examined the associations between dairy products and the risk of overweight or obesity, hypertension, and T2DM and tested for dose-response relations. We comprehensively searched PubMed, Embase, and Web of Science up to April 2021. Cohort studies were included if dairy food consumption was reported at a minimum of 3 levels or as continuous variables, and the associations were assessed with overweight or obesity, hypertension, and T2DM. Summary RRs and 95% CIs were estimated for the dose-response association. Restricted cubic splines were used to evaluate the linear or nonlinear relations. Among the 9887 articles retrieved, 42 articles were included. For overweight or obesity, a linear association was observed for total dairy, milk, and yogurt. The risk decreased by 25%, 7%, and 12% per 200-g/d increase for total dairy, high-fat dairy, and milk, respectively, and by 13% per 50-g/d increment of yogurt. For hypertension, a nonlinear association was observed with total dairy, whereas significant inverse associations were found for low-fat dairy (RR: 0.94; 95% CI: 0.90, 0.98) and milk (RR: 0.94; 95% CI: 0.92, 0.97) per 200-g/d intake increase. For T2DM, all types of dairy food consumption except for milk and low-fat dairy products showed nonlinear associations, with total dairy and yogurt intake associated with 3% and 7% lower risk per 200-g/d and 50-g/d intake increase, respectively. In conclusion, our study suggests that total dairy is associated with a low risk of overweight or obesity, hypertension, and T2DM, especially milk and yogurt for overweight or obesity, low-fat dairy and milk for hypertension, and yogurt for T2DM.

Hypovitaminosis D and Metabolic Syndrome in Postmenopausal Women

Metabolic syndrome (MetSyn) is a precursor for several cardiometabolic diseases. The prevalence of MetSyn is higher in postmenopausal women compared to premenopausal women. The role of vitamin D in postmenopausal women is not clearly understood. Hypovitaminosis D is more prevalent in postmenopausal women compared to premenopausal women. For this review, Pubmed, Cochrane, SCOPUS, Embase, and Google Scholar databases were searched up to August 2022. Findings from one randomized controlled trial (RCT) and ten cross-sectional studies were included in this review. Several cross-sectional studies (8 out of 10 reviewed) unequivocally demonstrated an inverse association between serum 25-hydroxyvitamin D concentrations and MetSyn. However, RCTs are severely lacking in the effect of vitamin D intake on the biomarkers of MetSyn and the prevalence of MetSyn. Therefore, caution should be used in recommending mega doses of vitamin D supplements for postmenopausal women because of the potential adverse effects associated with this vitamer.

Association of vitamin D status and cardio-metabolic risk factors in children and adolescents: the CASPIAN-V study

BACKGROUND

Metabolic syndrome (MetS) starts from early life and is one of the important underlying factors for non-communicable diseases (NCDs) in adulthood. Controversial evidence exists on the role of vitamin D deficiency in increasing the risk of pediatric MetS.

OBJECTIVE

This study aimed to assess the relationship between vitamin D level with MetS and its components in children and adolescents.

METHODS

This nationwide cross-sectional study was performed as part of a surveillance program in Iran. Participants were 2596 students, aged 7 to 18 years, living in 30 provinces. In addition to filling questionnaires, a physical examination was conducted, and blood samples were collected. The serum concentration of 25-hydroxy vitamin D (25(OH)D) was measured using the direct competitive immunoassay chemiluminescence method.

RESULTS

2596 students with a mean age of 12.2 y (55.1% boys) were recruited. Prevalence of vitamin D deficiency and insufficiency in participants was 10.6% (n = 276), and 60.5% (n = 1570), respectively. The prevalence of MetS was higher in the vitamin D deficient group. Students with deficient vitamin D levels had higher odds of MetS (OR: 4.25, 95%CI: 2.26-7.98), abdominal obesity (OR: 2.24, 95%CI: 1.61-3.12), low HDL-C (OR: 1.65, 95%CI: 1.18-2.30) and high fasting blood sugar (OR: 2.56, 95%CI: 1.43-4.57) in comparison to those with sufficient level of vitamin D.

CONCLUSION

Vitamin D deficiency was associated with increased odds of MetS and its components in the Iranian pediatric population. These findings underscore the importance of prevention and control of vitamin D deficiency in preventative programs against NCDs.

Association of serum 25-hydroxyvitamin D concentration with anthropometric measures in children and adolescents: the CASPIAN-V study

BACKGROUND

Serum 25-hydroxyvitamin D (25(OH)D) concentrations reflect vitamin D status, with deficiency implicated as an underlying factor for many adverse health effects. This study aims to analyze the association between vitamin D status and different anthropometric measures in a large pediatric population.

METHODS

This nationwide cross-sectional study was conducted in 2019 in blood samples obtained from school students of 30 provinces in Iran. Participants were 2596 children and adolescents aged 7-18 years. Weight, height, waist circumference (WC), hip circumference (HC), neck circumference (NC), and wrist circumference (WrC) were measured. Body mass index (BMI) and waist-to-height ratio (W/HtR) were calculated. Serum 25(OH)D concentrations were measured using chemiluminescent immunoassay.

RESULTS

Participants consisted of 55% boys, 71.3% urban inhabitants, with a mean (SD) age of 12.1 (3.0) years. Overall, vitamin D deficiency was documented in 10.6% of participants, insufficiency in 60.4%, and sufficiency in 29% of the population studied. The mean of BMI and WC was higher in the vitamin D deficient than in the vitamin D sufficient group (19.31 kg/m² and 69.24 cm vs. 18.34 kg/m² and 65.73 cm, respectively, P < 0.01). Multivariate linear regression models revealed a significant association of vitamin D insufficiency with WC and W/HtR (P < 0.05). Likewise, in the multivariate regression models, vitamin D deficiency was associated with BMI, WC, and W/HtR (P < 0.05).

CONCLUSION

Our findings on the inverse association between vitamin D status and some anthropometric measures underscore the importance of providing vitamin D by fortification and supplementation programs of vitamin D for the pediatric population.

LEVEL OF EVIDENCE

V.

Effects of Calcium and Vitamin D Co-supplementation on the Lipid Profile: A Systematic Review and Meta-analysis

PURPOSE

Calcium and vitamin D co-supplementation is common and widely used, but randomized, controlled trials (RCTs) have yielded inconclusive results concerning its impact on the serum lipid profile.

METHODS

A comprehensive literature search of Medline, Web of Science, Scopus, Embase, Cochrane Central Register of Controlled Trials, and clinical trial registry databases was conducted to identify placebo-controlled RCTs that were published through September 2020 and that evaluated the impact of calcium and vitamin D co-supplementation on total cholesterol (TC), triglycerides (TGs), low- and very-low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol (HDL-C). Standardized mean differences (SMDs) were pooled using random-effects meta-analysis models.

FINDINGS

Thirteen studies in a total of 2304 participants met the inclusion criteria. Calcium and vitamin D co-supplementation was associated with significant reductions in both TC (SMD, -0.81; 95% CI, -1.35 to -0.27; I² = 94.6%) and TGs (SMD, -0.50; 95% CI, -0.91 to -0.08; I² = 91.5%), and with a significant increase in HDL-C (SMD, 1.22; 95% CI, 0.60 to 1.83; I² = 95.4%). However, calcium and vitamin D co-supplementation were not found to be associated with significantly decreased low-density lipoprotein cholesterol (SMD, -0.39; 95% CI, -0.78 to 0.01; I² = 90.1%) or very-low-density lipoprotein cholesterol (SMD, -0.01; 95% CI, -0.70 to 0.69; I² = 82.3%).

IMPLICATIONS

The findings from the present systematic review and meta-analysis suggest that calcium and vitamin D co-supplementation has a beneficial effect on TC, TG, and HDL-C. Larger-scale, well-designed RCTs are needed to clarify the effect of calcium and vitamin D co-supplementation on all lipid-profile components.

Effect of extra virgin olive oil consumption on glycemic control: A systematic review and meta-analysis

AIMS

Several health benefits are contributed to extra virgin olive oil (EVOO). The polyphenol fraction of EVOO may be responsible for its cardioprotective impacts. This systematic review and meta-analysis aimed to investigate the effect of EVOO intake on glycemic parameters. Electronic literature searched through 1 September 2020 across MEDLINE/PubMed, Web of Science, and SCOPUS databases to find all clinical trials that reported the effect of EVOO intake on glycemic parameters [FBS(fasting blood glucose), insulin, HOMA-IR (Homeostatic Model Assessment for Insulin Resistance) and HbA1c (glycated hemoglobin A1c)] vs. control.

DATA SYNTHESIS

We pooled standardized mean differences (SMD) and 95% confidence intervals (CIs) from randomized clinical trials (RCTs) using random-effects models. Heterogeneity was assessed by Cochran Q-statistic and quantified (I²). We found 13 related trials comprising a total of 633 subjects. In pooled analysis, EVOO intake had no effect on FBS (SMD: -0.07; 95% CI: -0.20, 0.07; I² = 0.0%), insulin (SMD: -0.32; 95% CI: -0.70, 0.06; I² = 38.0%), and HOMA-IR (SMD: -0.32; 95% CI: -0.75, 0.10; I² = 51.0%). However, a decreasing trend was observed in these effects. Subgroup analysis based on age, health status, dose, and EVOO intake duration also did not significantly change results.

CONCLUSION

Although EVOO seems a promising hypoglycemic effects, we did not find any significant evidence that EVOO consumption impacts glucose homeostasis. Furthermore, well-designed RCTs with longer durations are still needed to evaluate the EVOO's efficacy on glycemic parameters.

Maternal vitamin D status and risk of gestational diabetes mellitus: A systematic review and meta-analysis of prospective cohort studies

BACKGROUND

No earlier systematic review and meta-analysis have been done on the association between maternal serum vitamin D status and risk of GDM among prospective studies. The current study was done to systematically review prospective cohort studies (with several years of follow-up) on the association between maternal serum vitamin D deficiency or insufficiency and risk of GDM.

METHODS

Relevant papers published up to January 2020 were searched through PubMed, MEDLINE, SCOPUS, EMBASE, and Google Scholar using suitable keywords. All prospective cohort studies reporting Hazard Ratios (HRs) or Relative Risks (RRs) and 95% Confidence Intervals (CI) for GDM across categories of maternal serum vitamin D status were included.

RESULTS

A total of 29 prospective and nested case-control studies were included in the current systematic review, of which 27 studies had sufficient data for the meta-analysis. Individuals with vitamin D deficiency had a 26% greater risk of developing GDM than those with normal serum vitamin D concentrations (OR: 1.26; 95% CI: 1.13, 1.41). In addition, a significant positive association was seen between combined vitamin D insufficiency and deficiency and risk of developing GDM (OR: 1.23; 95% CI: 1.11, 1.35). Dose-response analysis showed a significant U-shaped non-linear association between serum vitamin D concentrations and risk of developing GDM (P < 0.001), such that those with serum vitamin D concentrations between 40 and 90 nmol/L had significantly reduced risk of GDM.

CONCLUSIONS

We found a significant association between vitamin D deficiency and an increased risk of GDM. The lowest risk of GDM was found among those with a serum vitamin D levels of 40-90 nmol/L. Further studies, including randomized clinical trials, are needed to confirm our findings.

REGISTRATION

PROSPERO (ID: 180722), https://www.crd.york.ac.uk/prospero/.

Association of genetic polymorphisms in vitamin D receptor (ApaI, TaqI and FokI) with vitamin D and glycemic status in type 2 diabetes patients from Southern India

OBJECTIVES

To evaluate the association of VDR polymorphisms (FokI, TaqI and ApaI) with vitamin D levels and glycemic status in type 2 diabetes patients from Southern India.

METHODS

In this observational study, genotype frequencies and vitamin D levels of 200 cases (type 2 diabetes patients) were compared with 300 controls (unrelated anonymised stored samples of healthy volunteers) from south India. Serum 25 (OH) D levels were measured by immunoassay technique, glycated hemoglobin (HbA_1c) was measured using HPLC and genotyping of VDR polymorphisms were carried out using Real time Polymerase Chain Reaction (RT PCR).

RESULTS

About 69.2% of type 2 diabetes patients were found to have vitamin D deficiency. FokI polymorphism showed variations in serum 25 (OH) D levels, with AA and AG genotypes having significantly lower serum 25 (OH) D levels as compared to GG [13.24 (8.4) ng/ml, 15.02 (7.07) ng/ml and 20.67 (13.64) ng/ml respectively]. There was no difference in HbA_1c levels with respect to the vitamin D levels and VDR polymorphisms.

CONCLUSIONS

AA and AG genotypes of FokI polymorphisms are associated with low serum 25 (OH) D levels. However there was no association between VDR polymorphisms and glycemic status in south Indian type 2 diabetes patients.

Association of genetic polymorphisms in vitamin D receptor (ApaI, TaqI and FokI) with vitamin D and glycemic status in type 2 diabetes patients from Southern India

OBJECTIVES

To evaluate the association of VDR polymorphisms (FokI, TaqI and ApaI) with vitamin D levels and glycemic status in type 2 diabetes patients from Southern India.

METHODS

In this observational study, genotype frequencies and vitamin D levels of 200 cases (type 2 diabetes patients) were compared with 300 controls (unrelated anonymised stored samples of healthy volunteers) from south India. Serum 25 (OH) D levels were measured by immunoassay technique, glycated hemoglobin (HbA1c) was measured using HPLC and genotyping of VDR polymorphisms were carried out using Real time Polymerase Chain Reaction (RT PCR).

RESULTS

About 69.2% of type 2 diabetes patients were found to have vitamin D deficiency. FokI polymorphism showed variations in serum 25 (OH) D levels, with AA and AG genotypes having significantly lower serum 25 (OH) D levels as compared to GG [13.24 (8.4) ng/ml, 15.02 (7.07) ng/ml and 20.67 (13.64) ng/ml respectively]. There was no difference in HbA1c levels with respect to the vitamin D levels and VDR polymorphisms.

CONCLUSIONS

AA and AG genotypes of FokI polymorphisms are associated with low serum 25 (OH) D levels. However there was no association between VDR polymorphisms and glycemic status in south Indian type 2 diabetes patients.

Consumption of Dairy Products in Relation to Type 2 Diabetes Mellitus in Chinese People: The Henan Rural Cohort Study and an Updated Meta-Analysis

Recent studies on whether dairy consumption is associated with type 2 diabetes mellitus (T2DM) have yielded inconsistent results, so we explored the relationship between dairy consumption and T2DM through a large-sample, cross-sectional study and a meta-analysis. In the meta-analysis, summary relative risks (RRs) of 23 articles were compiled with a random effects model, and a restricted cubic spline regression model was used to explore whether there is a nonlinear relationship between dairy intake and T2DM risk. This cross-sectional study used baseline data from 38,735 participants of the Henan Rural Cohort study and the association between dairy consumption and T2DM was analyzed by a logistic regression model. The meta-analysis revealed a borderline negative significant association between total dairy intake and risk of T2DM, the RR and 95% confidence interval (CI) was 0.94; (0.89, 1.00), and the risk was lowest at 270 g daily dairy intake. In the cross-sectional study, there were 3654 T2DM patients and 68.3 percent of the respondents had no dairy intake. The average intake of dairy in the total population was 12 g per day. Fully adjusted analyses suggested positive associations, with an odds ratio (OR) comparing the highest with the zero intake of 1.34 (95% CI: 1.22, 1.48) for all participants, which was unaffected by sex. Dairy intake in rural areas of Henan province is low, and we found, in the context of overall low dairy intake, that a high intake was positively associated with T2DM, which is inconsistent with the meta-analysis results suggesting that dairy has marginal protective effects against T2DM.

The Relationship between Vitamin D Status and Visceral Fat Accumulation in Males with Type 2 Diabetes

Vitamin D deficiency may play an important role in obesity. The aim of the study was to explore the relationship between vitamin D status and visceral fat accumulation in males with type 2 diabetes. A cross-sectional study was conducted on 128 adult males with type 2 diabetes in Qinhuangdao. The nutritional status of vitamin D was assessed by circulating levels of 25(OH)D, vitamin D deficiency <30 nmol/L, vitamin D insufficiency 30-50 nmol/L and vitamin D sufficiency >50 nmol/L. Accumulation of visceral fat was defined as visceral fat area ≥100 cm². The prevalence of visceral fat accumulation was 35.9%. The prevalence of visceral fat accumulation was 14.6%, 45.1% and 50.0% in type 2 diabetes with vitamin D sufficiency, vitamin D insufficiency and vitamin D deficiency, respectively. In multiple logistic regression analysis, subjects with vitamin D insufficiency [OR=4.255, p=0.012] and vitamin D deficiency [OR=6.122, p=0.022] were more likely to have visceral fat accumulation compared with subjects with vitamin D sufficiency. Visceral fat accumulation linked to the cluster of cardiometabolic risk factor in males with type 2 diabetes. There was a significant correlation between vitamin D status and visceral fat accumulation in males with type 2 diabetes.

Attenuating properties of Rubus fruticosus L. on oxidative damage and inflammatory response following streptozotocin-induced diabetes in the male Wistar rats

Purpose

Diabetes mellitus is a prevalent metabolic disorder that entails numerous complications in various organs. In current era, different types of diseases are being treated by the applications of herbs. The present study is aimed at investigating the anti-inflammatory and antioxidant effects of the Rubus fruticosus hydroethanolic extracts (RFHE) in the streptozotocin (STZ)-induced diabetic rats.

Methods

At this experimental research, male Wistar rats with the weight of 220 ± 20 g, were categorized randomly into five groups of vehicles as control, STZ (60 mg kg^- 1 of body weight, intraperitoneally (i.p.)) and RFHE (50, 100 and 200 mg kg^- 1, i.p.). In the last stage (end of week 4) of the experiment, after being euthanized, the blood samples of the rats were collected for measuring malondialdehyde (MDA), glutathione (GSH), total antioxidant status (TAS) as well as inflammatory markers like tumor necrosis factor (TNF)-α, interleukin (IL)-6 and C-reactive protein (CRP).

Results

Data from this study was revealed that diabetes causes oxidative damage and consequently the serum level of inflammatory markers rises. RFHE was shown to be significantly correlated with lowering the level of MDA, TNF-α, IL-6 and CRP of diabetic rats. Moreover, RFHE significantly elevated the GSH and TAS serum levels in diabetic rats when compared with STZ group.

Conclusions

RFHE might have anti-diabetic properties; this outcome may be mediated by high antioxidant and anti-inflammatory effects.

A systematic review and meta-analysis of the effect of Vitamin D-fortified food on glycemic indices

Some reports indicated that Vitamin D may improve glycaemia indices in diabetic patients. The aim of this systematic and meta-analysis was to evaluate effects of Vitamin D fortification on indices of glycemic control. Six databases (PubMed/Medline, ISI Web of Knowledge, Cochrane Library, Science Direct, Scopus, and Google Scholar) were searched, for randomized controlled trials that were published up to September 2018 and that compared the effect of Vitamin D-fortified food versus regular diet in relation to glycemic control. Of the 4,379 studies originally found, 11 articles remained to be assessed for meta-analysis. Vitamin D fortification was associated with a significant improvement in fasting serum glucose (mean difference [MD]: -2.772; 95% confidence interval [CI]: -5.435 to -0.109) and fasting serum insulin (MD: -2.937; 95% CI: -4.695 to -1.178) in patients with Type 2 diabetes mellitus. A diet with food enriched with Vitamin D was associated with a significant improvement in homeostatic model assessment of insulin resistance (MD: -1.608; 95% CI: -3.138 to -0.079) but was not associated with a significant reduction in hemoglobin A1C (MD: 0.034; 95% CI: -0.655 to 0.069). This meta-analysis indicates that Vitamin D fortification improves indices of glycemic control. Hence, food fortified with Vitamin D may be of potential therapeutic value in diabetic patients, as an adjuvant therapy.

Low pretreatment serum concentration of vitamin D at breast cancer diagnosis in postmenopausal women

OBJECTIVE

The aim of the study was to evaluate the rate of and risk factors for low pretreatment vitamin D (VitD) levels in postmenopausal breast cancer (BC) women, compared with postmenopausal women without BC.

METHODS

A cross-sectional clinical study was conducted to compare 209 women with BC (case group) to 418 women without BC (control group), age range: 45 to 75 years. The case group consisted of women diagnosed with BC, amenorrhea ≥12 months, aged ≥45 years, without use of medication or clinical conditions that might interfere with VitD levels. The control group consisted of women with amenorrhea ≥12 months, aged ≥45 years, without BC. The groups were matched for age and time since menopause, at a case: control ratio of 1:2. Serum 25-hydroxyvitamin-D [25(OH)D] concentration was measured in all women 10 to 20 days after BC diagnosis and before the proposed treatment. Serum levels ≥30 ng/mL were defined as sufficient. The Student's t test or gamma distribution, χ test, and logistic regression (odds ratio, OR) were used for statistical analysis.

RESULTS

The BC group had a higher body mass index (BMI) and higher percentage of obesity than the control group (57.4% vs 40.2%, P < 0.0001). In addition, rates of insufficient (20-29 ng/mL) and deficient (<20 ng/mL) 25(OH)D levels were higher in BC patients than in controls (55.6% vs 49.3%, P = 0.039 and 26.2% vs 20.3%, P = 0.018), respectively. In risk analysis (adjusted for age, time since menopause, and BMI), BC patients had a 1.5-fold higher risk of developing low VitD levels (OR = 1.52, 95% CI, 1.04-2.22, P = 0.029) than women without BC.

CONCLUSIONS

Postmenopausal women had an increased risk of VitD deficiency at the time of BC diagnosis, associated with a higher rate of obesity, than women of the same age group without cancer.

Vitamin D status of overweight and obese Bangladeshi adults

Background:

Both obesity and vitamin D deficiency are pandemics and both have influences on cardiovascular parameters. The reported prevalence of vitamin D deficiency in obesity is high. Data relating to vitamin D status in obese is currently lacking in Bangladesh.

Objective:

To discover the vitamin D status in Bangladeshi overweight and obese adults.

Subjects and Methods:

This cross-sectional study, conducted in a specialized endocrine center of Bangladesh, evaluated 500 consecutive overweight or obese subjects, diagnosed according to body mass index (BMI) categories applicable to the south Asian population. Serum 25(OH)D was measured by using the enzyme-linked fluorescent assay (ELFA) method, and the cutoffs described by the Endocrine Society were used to define vitamin D status.

Results:

The mean age of the study subjects was 45.85 (±11.41) years; most (59.6%) of them were in the age group 40–59 years; almost three-fourth (72.4%) were females; an almost equal number of them came from urban (33.8%), semi-urban (29.6%), and rural (36.6%) areas; three-fourth (74.2%) were homemaker. Their mean BMI was 29.54 (±3.11) kg/m²; the frequencies of overweight, class I obesity, class II obesity, and class III obesity were 27.6%, 57.4%, 12.2%, and 2.8%, respectively. The mean serum 25(OH)D level was 25.25 (±11.97) ng/mL. 27.4% were sufficient, and 33.4% were insufficient for vitamin D, whereas 39.2% had vitamin D deficiency. The 25(OH)D level did not differ across different age groups, gender, residence, education status, occupation, and income status. The 25(OH)D levels were also indifferent in overweight, obese class I, obese class II, and obese class III subjects. None of the demographic, anthropometric, and biochemical variables (except low-density lipoprotein cholesterol) correlated with 25(OH)D levels.

Conclusions:

The prevalence of vitamin D deficiency in overweight and obese Bangladeshi adults is very high.

The effect of omega-3 and vitamin D co-supplementation on glycemic control and lipid profiles in reproductive-aged women with pre-diabetes and hypovitaminosis D: a randomized controlled trial

BACKGROUND

Prediabetes can predispose the individual to type 2 diabetes in the long-term. The present study was conducted to determine the effectiveness of vitamin D and omega-3 co-supplementation on glycemic control and serum lipid profiles in women of reproductive age with prediabetes and hypovitaminosis D.

METHODS

The present factorial, triple-blind, clinical trial was conducted on 168 women of reproductive age with prediabetes and hypovitaminosis D. The participants were assigned to four groups based on block randomization method: the placebo group received omega-3 and vitamin D placebos; the omega-3 group took omega-3 supplements and vitamin D placebos; the vitamin D group received omega-3 placebos and vitamin D supplements and the co-supplementation group. The groups received every 2 weeks 50,000 IU pearls of vitamin D and twice-daily doses of 1000-mg omega-3 tablets or placebos for 8 weeks. Dietary intake, physical activity, anthropometric indices and blood biochemical tests were measured at the beginning and end of the study. Analysis was performed using two-way mixed ANOVA.

RESULTS

A significant reduction was observed in fasting glucose, insulin, homeostasis model assessment-beta cell function, weight and waist circumference in the co-supplementation group compared to the other three groups (P < 0.05). Moreover, high-density lipoprotein-cholesterol levels increased significantly in the co-supplementation group compared to the other three groups (P < 0.05). Despite the fact that homeostasis model assessment-insulin resistance, total cholesterol, triglyceride and low-density lipoprotein-cholesterol levels decreased after intervention in the co-supplementation group, there was no significant difference between the groups in these outcomes.

CONCLUSION

Vitamin D and omega-3 co-supplementation improved fasting serum glucose, insulin, high-density lipoprotein-cholesterol level, homeostasis model assessment-beta cell function, weight and waist circumference in women of reproductive age with prediabetes and hypovitaminosis D. This co-supplementation can therefore be recommended for glycemic control in these women.Trial registration Iranian Registry of Clinical Trials Code: IRCT20100130003226N17. Registered on 9 Feb. 2019.

Association of Serum 25-Hydroxyvitamin D Level With Metabolic Phenotypes of Obesity in Children and Adolescents: The CASPIAN-V Study

Background and Objective: Different metabolic phenotypes of obesity are related to cardiometabolic risk factors in children and adolescents. Vitamin D, as one important factor, could be related to different subgroups of metabolic obesity and might affect metabolic disorders. The purpose of this study was to evaluate the relationship between serum 25-hydroxyvitamin D concentration and subsets of metabolic phenotypes of obesity in children and adolescents. Methods: This nationwide cross-sectional study was conducted in the framework of the fifth survey of a national surveillance program, the CASPIAN study. Overall, 2,594 students aged 7-18 years were assessed for 25-hydroxyvitamin D status. Metabolic syndrome (MetS) was defined according to the ATP III criteria modified for the pediatric age group. Participants were classified into four metabolic phenotypes of obesity according to categories of the BMI and metabolic status: "metabolically healthy obese" (MHO), "metabolically non-healthy non-obese" (MNHNO), "metabolically non-healthy obese" (MNHO), and "metabolically healthy non-obese" (MHNO). Multinomial logistic regression analysis was performed for evaluating the association of 25-hydroxyvitamin D status with different metabolic phenotypes of obesity. Results: In this study, 85.2% of participants were classified as MHNO, 11.0 % as MHO, 2.5% as MNHNO, and 1.3% as MNHO. The frequency of hypovitaminosis D was more prevalent in MNHO (85.3%) than in other phenotypes (MHNO: 70%; MHO: 76.5%; MNHNO: 78.1%, respectively; p < 0.05). In the multivariate model, hypovitaminosis D significantly increased the odds of being MHO (OR: 1.46; 95% CI: 1.07-1.77) and MNHO (OR: 2.89; 1.05-8.31) compared to the healthy group. Likewise, in multivariate model, per each unit (ng/mL) increment in 25-hydroxyvitamin D concentration, the odds of MNHNO and MNHO decreased significantly by 7% (OR: 0.93; 0.91-0.96) and 6% (OR: 0.94; 0.91-0.98) respectively. Conclusion: Our results support the hypothesis that 25-hydroxyvitamin D concentration is associated with metabolic obesity phenotypes. Longitudinal studies are necessary to assess the clinical impacts of this finding.

The Effect of Treating Vitamin D Deficiency or Insufficiency on Serum Adiponectin, Leptin and Insulin Resistance of Type 2 Diabetes Mellitus Patients: A Pilot Study

Vitamin D deficiency is considered as one of the most prevalent healthcare problems in the world. Vitamin D contributes to insulin synthesis and secretion. Deficiency of vitamin D leads to insulin resistance which is the major cause of type 2 diabetes mellitus. We aim to evaluate the effect of treating vitamin D deficiency or insufficiency on serum adiponectin, leptin, and leptin to adiponectin ratio (LAR) of type 2 diabetes mellitus patients. Forty patients with type 2 diabetes mellitus were included according to the inclusion criteria of the study. Fasting venous blood samples were obtained and evaluated before and after the treatment of vitamin D deficiency or insufficiency. Then, blood levels of leptin, adiponectin, and LAR (an indicator of insulin resistance) were measured. The results of study indicate a significant decline in circulating leptin and adiponectin after vitamin D treatment, but it doesn't cause a noteworthy change in LAR. Furthermore, the study demonstrates that female gender, higher body mass index, and triglyceride levels increase LAR significantly. It was concluded that the treatment of vitamin D deficiency or insufficiency doesn't change insulin resistance in diabetic patients. Moreover, we concluded that LAR is not a reliable method to compare insulin resistance between men and women due to sex-related differences in adipose tissue.

Isolated vitamin D supplementation improves the immune-inflammatory biomarkers in younger postmenopausal women: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

The aim of this study was to evaluate the effect of vitamin D (VitD) supplementation on immune-inflammatory biomarkers in younger postmenopausal women.

METHODS

In this double-blind, placebo-controlled trial, 160 postmenopausal women aged 50 to 65 years with amenorrhea ≥12 months were randomized into two groups: VitD group, oral supplementation with 1000 IU VitD3/day (n = 80) or placebo group (n = 80). The intervention time was 9 months, and the women were assessed at baseline and endpoint. Serum levels of interleukins (ILs)-1β, IL-5, IL-6, IL-10, IL-12ρ70, IL-17α, tumor necrosis factor-alpha, and interferon-gamma were determined by immunoassay. Plasma concentrations of 25-hydroxyvitamin D [25(OH)D] were measured by high-performance liquid chromatography. Per-protocol analysis was adopted as the statistical method using a gamma distribution and repeated measures design, followed by Wald's multiple comparisons test.

RESULTS

The two groups were similar at baseline in terms of clinical and laboratory parameters. After 9 months, there was a significant increase of 25(OH)D levels in the VitD group (+45.4%, P < 0.001) and a decrease (-18.5%, P = 0.049) in the placebo group. A significant decrease in IL-5, IL-12p70, IL-17α, tumor necrosis factor-alpha, and interferon-gamma levels was observed in the VitD group (P < 0.05). IL-5 and IL-6 levels were significantly lower in the VitD group compared to the placebo group (P < 0.05). There were no significant intervention effects on serum IL-1β or IL-10 levels in either group (P > 0.05).

CONCLUSIONS

In younger postmenopausal women, isolated supplementation with 1000 IU of VitD3 for 9 months was associated with a reduction in proinflammatory biomarkers.

Vitamin D Is Inversely Related to Obesity: Cross-Sectional Study in a Small Cohort of Serbian Adults

Objective: Vitamin D (vitD) mediates numerous health conditions other than bone health and mineralization. Its role in cardiometabolic condition is still inconclusive. Methods: We conducted a cross-sectional study in 87 apparently healthy Serbian adults. We assessed their dietary intake, anthropometric and biochemical parameters, blood pressure, and vitD status (as serum 25-hydroxyvitamin D, 25(OH)D). Unexpectedly, the status was significantly higher in January than in July. Therefore, we pooled the data from two time points, to enhance the statistical power for carrying out association analyses. We employed linear regression models to evaluate the associations between vitD status and the obesity biomarkers of serum lipids and blood pressure. Results: Mean vitD intake of 3.85 ± 4.71 μg in the cohort was below recommended. Of the subjects in the pooled cohort, 60.58% were vitD deficient (with serum 25(OH)D below 50 nmol/L), with the majority of them being women who were overweight. VitD status tended to be inversely related to percent body fat and waist/height ratio in the crude regression model. After age and gender adjustment, the status was significantly related to waist circumference, waist/height ratio, and waist/hip ratio (β = -0.116, 95% confidence interval [CI]: -0.206, -0.025, β = -0.001, 95% CI: -0.001, 0.000, and β = -0.001, 95% CI: -0.001, 0.000, respectively). These associations remained only within women. Fully adjusted models supported the notion of vitD being independently associated with central adiposity, regardless of age, gender, and total obesity. Conclusions: In apparently healthy adults with low vitD intake, vitD status was inversely associated with obesity parameters, pronouncedly in women. Our data support the need for development and implementation of public health policies on increasing vitD intake also as part of obesity management strategies.

Effect of vitamin D on the variability of blood pressure in premenopausal and menopausal hypertensive women in the area of Blida (Algeria)

OBJECTIVE

To evaluate the effect of 25 (OH) vitamin D supplementation on blood pressure (BP) variability in hypertensive women in the pre-menopausal and post-menopausal periods.

MATERIALS AND METHODS

881 hypertensive women prospectively followed for an interventional study between January 2016 and September 2017, in specialized consultation at the department of internal medicine at the Blida University Hospital (Algeria). Four hundred and thiry nine premenopausal women (group I) and 442 menopausal women (group II). The initial serum 25 (OH) D level for each group was determined by the enzyme immunoassay. In groups I and II, we identified 2 subgroups, A: insufficiency (vit D between 29 and 20ng/ml) and B: deficiency (vit D less than 20ng/L). Antihypertensive therapy was supplemented with an additional 200000IU/month cholecalciferol for the two B subgroups. The variability in BP was calculated as the ratio of mean systolic and diastolic BP during daytime and nighttime, with performing ambulatory BP measurement at baseline, 3, 6, and 12 months of follow-up.

RESULTS

At inclusion, the level of 25 (OH) D was lower (P<0.05) in subgroups IB (19.3±8.5ng/ml) and IIB (18.2±9, 5ng/ml) compared to subgroups IA (28.1±10.7ng/ml) and IIA (25.2±10.1ng/ml). After supplementation, the level of 25 (OH) D increased in subgroup IB (38.3±11.9ng/ml) and in subgroup IIB (37.3±10, 5ng/ml) and became higher (P<0.001) than in subgroups IA and IIA. Between subgroups IA and IB, at inclusion, there is no difference (P>0.05) in the SBP and DBP variability during the day and at night. After treatment, the variability of the SBP at night became lower (P<0.02) in group IB compared to group IA. In subgroup IIB, daytime variability indices were higher (P=0.04) at inclusion than in group IIA. After treatment, the variability of SBP during the day decreased but remained the highest (P<0.05) in subgroup IIB (14.8±10.8mmHg) compared to subgroup IB (12.0±8.1mmHg), as well as to subgroups IIA (10.9±9.8mmHg) and IA (10±8.1mmHg). We found a significant correlation of cholecalciferol with the variability of SBP during the day.

CONCLUSIONS

Vitamin D deficiency appears to be a factor of BP variability. Although the variability of the postmenopausal group remains higher than that of the other groups, the correction of the level of 25 (OH) D by the supply of cholecalciferol 200000 IU per month leads to a reduction in the variability of BP in the studied hypertensive women could help to prevent morbimortal complications.

Evaluating Vitamin D Status in Pre- and Postmenopausal Type 2 Diabetics and Its Association with Glucose Homeostasis

Background

Type 2 Diabetes Mellitus (T2DM) and menopause are associated with vitamin D status. Oestrogen decline during menopausal stages promotes hypovitaminosis D. However, the interplay between vitamin D, menopause, lifestyle, and T2DM cannot be overlooked. This study assessed vitamin D status among pre- and postmenopausal T2DM women and determined its association with glycemic control and influence of lifestyle habits on hypovitaminosis D.

Methods

This cross-sectional study was conducted at the Komfo Anokye Teaching Hospital, Kumasi, Ghana. Structured questionnaires were administered to 192 T2DM women; blood samples were collected for estimation of 25(OH) D and insulin using ELISA. Fasting blood glucose (FBG), lipid profile, glycated haemoglobin (HbA1c), and calcium were measured. Statistical analyses were performed using Graphpad Prism 6.

Results

The prevalence of vitamin D inadequacy was 92.2%. Hypovitaminosis D was more prevalent among the postmenopausal T2DM women (63.8% versus 58.2%). Hypovitaminosis D significantly associated with insulin [R² = 0.01760, p = 0.0008], HbA1c [R² = 0.3709, p = <0.0001], and FBG [R² = 0.3465, p = 0.0001] in only the postmenopausal women.

Conclusion

Vitamin D deficiency is prevalent in pre- and postmenopausal T2DM but higher among postmenopausal women. Adequate vitamin D levels in both groups were associated with improved glucose control while hypovitaminosis D in the postmenopausal women was related to poorer glucose control. Vitamin D screening should be incorporated into management plan for T2DM to serve as an early tool for prevention of vitamin D deficiency.

Is There Any Relationship between Plasma 25-Hydroxyvitamin D₃, Adipokine Profiles and Excessive Body Weight in Type 2 Diabetic Patients?

A growing interest in the role of vitamin D in metabolic diseases led us to study the relationships between 25-hydroxyvitamin D₃ (25(OH)D₃) and the profiles of selected adipokines in type 2 diabetic (T2DM) patients. The study comprised 92 type 2 diabetics divided into quartiles regarding 25(OH)D₃ concentration. Each group was divided into male and female subgroups. All the studied patients had their anthropometric and biochemical parameters determined. Plasma 25-hydroxyvitamin D₃ concentration was determined by HPLC, while the selected adipokines (leptin, adiponectin, resistin and visfatin) by ELISA methods. The ratio of leptin to adiponectin (L/A) was calculated for all the patients. In 85.3% of diabetics a full (<20 ng/mL) or moderate (20-30 ng/mL) vitamin D deficit was found. Irrespective of sex, plasma leptin concentration decreased across increasing quartiles of 25(OH)D₃ level. In women, 25(OH)D₃ was negatively correlated with BMI, leptin level as well as L/A ratio, and positively with adiponectin concentration. In men, 25(OH)D₃ was positively correlated with HDL and negatively with systolic blood pressure (SBP), leptin level and L/A ratio. Considering all the patients, there ocurred a significant negative correlation between 25(OH)D₃ and SBP, BMI, WHR, TG, leptin and L/A ratio and positive ones between 25(OH)D₃ and both adiponectin and HDL. The results of the study support the existence of the relationship among vitamin D, obesity and leptin in type 2 diabetic patients.

Vitamin D deficiency is associated with metabolic syndrome in postmenopausal women

OBJECTIVE

To evaluate the association between vitamin D (VD) deficiency and risk factors for metabolic syndrome (MetS) in postmenopausal women.

STUDY DESIGN

Observational, cross-sectional cohort study.

MAIN OUTCOME MEASURES

In this study, 463 women, aged 45-75 years, with amenorrhea >12months, without VD supplementation or established cardiovascular disease were included. Clinical and anthropometric data were collected. Biochemical parameters, including total cholesterol (TC), HDL, LDL, triglycerides, glucose, insulin and 25-hydroxyvitamin-D [25(OH)D] were measured. Women meeting three or more of the following criteria were diagnosed with MetS: waist circumference >88cm, triglycerides ≥150mg/dL, HDL <50mg/dL, blood pressure ≥130/85mmHg and glucose ≥100mg/dL. Serum 25(OH)D levels were classified as sufficient (≥30ng/mL), insufficient (20-29ng/mL) or deficient (<20ng/mL). ANOVA, chi-square test and logistic regression (odds ratio, OR) were used for statistical analysis.

RESULTS

Serum 25(OH)D levels were sufficient in 148 women (32.0%), insufficient in 151 (32.6%) and deficient in 164 (35.4%). Women with low 25(OH)D levels had higher TC, triglycerides, insulin and HOMA-IR levels (p<0.05). MetS was detected in 57.8% (182/315) of women with hypovitaminosis D (insufficient and deficient) and in 39.8% (59/148) of those with sufficient VD​​ (p=0.003). In a multivariate logistic regression analysis, a low 25(OH)D level (<30ng/mL) was significantly associated with MetS (OR1.90, 95%CI=1.26-2.85), high triglyceride levels (OR1.55, 95%CI=1.13-2.35), and low HDL levels (OR1.60, 95%CI=1.19-2.40) (p<0.05) compared with women with sufficient 25(OH)D levels, after adjusting for age, time since menopause, body mass index, smoking and physical exercise. The mean concentration of 25(OH)D decreased with increasing numbers of MetS components (p=0.016).

CONCLUSIONS

VD deficiency in postmenopausal women was associated with a higher prevalence of MetS. Women with VD deficiency had a higher risk of MetS, hypertriglyceridemia and low HDL than those with adequate levels.

Maternal vitamin D, DNA methylation at imprint regulatory regions and offspring weight at birth, 1 year and 3 years

BACKGROUND/OBJECTIVE

Vitamin D deficiency during pregnancy is associated with poor birth outcomes in some studies, but few have examined weight beyond birth. In addition, little is known about how vitamin D influences DNA methylation of regulatory regions known to be involved in growth, as possible mediators to weight status in offspring.

SUBJECTS/METHODS

We conducted linear regressions to assess maternal plasma 25-hydroxyvitamin D (25(OH)D) by quartile and birth weight for gestational age z-score, 1-year weight-for-length z-score and 3-year body mass index (BMI) z-score among 476 mother/infant dyads from a prospective cohort. We assessed maternal 25(OH)D and infant DNA methylation at nine differentially methylated regions (DMRs) of genomically imprinted genes with known functions in fetal growth, including H19, IGF2, MEG3, MEG3-IG, MEST, NNAT, PEG3, PLAGL1 and SGCE/PEG10.

RESULTS

Mean (standard deviation, s.d.) maternal 25(OH)D was 41.1 (14.2) nmol l^-m at a mean (s.d.) of 13.2 (5.5) weeks gestation. After adjustment for potential confounders, the first (Q1) and second (Q2) quartiles of 25(OH)D, compared to the fourth (Q4), were associated with lower birth weight for gestational age z-scores (-0.43 units; CI: -0.79, -0.07; P=0.02 for Q1 and -0.56 units; CI: -0.89, -0.23; P=0.001 for Q2). Q1 compared to Q4 was associated with higher 1-year weight-for-length z-scores (0.78 units; 0.08, 1.54; P=0.04) and higher 3-year BMI z-scores (0.83 units; 0.11, 0.93; P=0.02). We did not observe associations between maternal 25(OH)D and methylation for any of the nine DMRs after correcting for multiple testing.

CONCLUSIONS

Reduced maternal 25(OH)D was associated with lower birth weight for gestational age z-scores but higher 1-year weight-for-length and 3-year BMI z-scores in offspring. However, 25(OH)D does not appear to be operating through the regulatory sequences of the genomically imprinted genes we examined.

Vitamin D status and its association with insulin resistance among type 2 diabetics: A case -control study in Ghana

Background

Vitamin D plays a major role in physiological processes that modulate mineral metabolism and immune function with probable link to several chronic and infectious conditions. Emerging data suggests a possible influence of vitamin D on glucose homeostasis. This study sought to provide preliminary information on vitamin D status among Ghanaian type 2 diabetics and assessed its association with glucose homeostasis.

Methods

In a case control study, 118 clinically diagnosed Type 2 Diabetes Mellitus (T2DM) patients attending Diabetic Clinic at the Nkawie Government Hospital were enrolled between October and December 2015. Hundred healthy non-diabetics living in Nkawie district were selected as controls. Structured questionnaires were administered to obtain socio-demographic data. Venous blood samples were taken from both cases and controls to estimate their FBG, Lipid profile spectrophotometrically and IPTH, 25OHD by ELISA. Statistical analyses were performed using SPSS v20.0 Statistics.

Results

The average age of the study participants was 58.81years for cases and 57.79year for controls. There was vitamin D deficiency of 92.4% among T2DM cases and 60.2% among the non diabetic controls. Vitamin D deficiency did not significantly associate with HOMA-β [T2DM: r² = 0.0209, p = 0.1338 and Control: r² = 0.0213, p = 0.2703] and HOMA-IR [T2DM: r² = 0.0233, p = 0.1132 and Control: r² = 0.0214, p = 0.2690] in both the controls and the cases.

Conclusion

Vitamin D deficiency is prevalent in both T2DM and non-diabetics. There is no association between vitamin D deficiency and insulin resistance or beta cell function in our study population. Vitamin D supplementation among type 2 diabetics is recommended.

Role of Vitamin D on glycemic control and oxidative stress in type 2 diabetes mellitus

Background:

Vitamin D deficiency may play a key role in the development of impaired glucose tolerance, type 2 diabetes mellitus (T2DM), and metabolic syndrome. Several studies have shown that Vitamin D has an antioxidant property. We aimed to investigate 25-hydroxy Vitamin D (25[OH]D) levels in patients with T2DM and in nondiabetic healthy controls and to ascertain the impact of 25(OH)D levels on glycemic control and oxidative stress in T2DM patients.

Materials and Methods:

Thirty male patients with T2DM and twenty age- and socioeconomic status-matched male healthy controls were included in the study. Fasting and postprandial blood sugar and glycated hemoglobin (HbA1c) were measured. Enzyme activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx) was determined by spectrophotometric assay, and serum levels of 25(OH)D were measured using radioimmunoassay.

Results:

Serum Vitamin D levels were significantly lower in patients with T2DM than healthy controls (P = 0.015). There was a significantly lower GPx activity in patients with T2DM than controls (P = 0.048), but the difference in SOD activity did not reach statistical significance. There was a significant negative correlation between serum Vitamin D levels and HbA1c (P = 0.016), but no statistical correlation was shown between serum Vitamin D levels and GPx and SOD.

Conclusion:

We conclude that low level of Vitamin D might play a significant role in T2DM pathogenesis. Hence, Vitamin D supplementation may improve glycemic control and oxidative stress in T2DM.

Physical Activity and Risk of Colon Cancer in Diabetic and Nondiabetic US Adults

OBJECTIVE

To determine whether moderate to vigorous physical activity is associated with a decreased risk of colon cancer in diabetic patients.

PATIENTS AND METHODS

We evaluated the association between physical activity and colon cancer in 25,753 patients with a self-reported history of diabetes and in 274,965 nondiabetic individuals from the National Institutes of Health-AARP Diet and Health Study who were aged 50 to 71 years in 1995-1996. Moderate to vigorous physical activity was assessed at baseline using a self-administered questionnaire. Follow-up for colon cancer incidence extended to December 31, 2011.

RESULTS

During 13.0 years of follow-up, 480 diabetic patients and 4151 nondiabetic individuals had development of colon cancer. Among diabetic patients, compared with never/rarely engaging in physical activity, more than 7 h/wk of physical activity exhibited a reduced risk of colon cancer in the age- and sex-adjusted model (hazard ratio [HR], 0.74; 95% CI, 0.56-0.996; P=.16 for trend). This association was attenuated and no longer statistically significant after additional control for other covariates (HR, 0.78; 95% CI, 0.58-1.05; P=.29 for trend). By comparison, physical activity was inversely related to colon cancer risk in nondiabetic individuals (multivariate-adjusted HR, 0.81; 95% CI, 0.73-0.89; P<.001 for trend).

CONCLUSION

In this investigation of the relationship between physical activity and colon cancer in diabetic patients, we found a statistically significant inverse relationship in the age- and sex-adjusted model, which was no longer statistically significant in the multivariate-adjusted model. A reduced risk was noted among nondiabetic individuals, irrespective of other covariates. Future studies with a larger number of participants are required to explore whether physical activity beneficially affects colon cancer risk among diabetic patients.

The relationship between vitamin D and obesity

Currently, vitamin D deficiency and obesity are pandemic diseases and they are associated with cardiovascular (CV) disease, metabolic syndrome and type 2 diabetes mellitus (T2DM) and other diseases. Concentrations of 25-hydroxyvitamin D (25(OH)D) (25D) are considered as the best indicator of total body vitamin D stores. An association between reduced circulating 25D concentrations and obesity is well known, but the mechanisms are not totally clear. The role of vitamin D supplementation is still uncertain and prospective interventions will establish its influence, if any, in the treatment of obesity. Vitamin D deficiency is associated with the presence of a cardiometabolic risk profile in the obese. Future trials may establish a role for Vitamin D supplementation in individuals at increased CV risk.

Obesity and vitamin D deficiency: trends to promote a more proatherogenic cardiometabolic risk profile

Vitamin D deficiency is associated with cardiometabolic risk factors (eg, hypertension, insulin resistance, type 2 diabetes mellitus, obesity, and dyslipidemia). We studied 50 obese patients (body mass index [BMI]: 43.5 ± 9.2 kg/m(2)) and 36 normal weight participants (BMI: 22.6 ± 1.9 kg/m(2)). The prevalence of vitamin D deficiency (25-hydroxyvitamin D, 25(OH)D < 50 nmol/L) was 88% among obese patients and 31% among nonobese individuals; 25(OH)D levels were lower in the obese group (27.3 ± 13.7 vs 64.6 ± 21.3 nmol/L; P < .001). There was a negative correlation between vitamin D level and anthropometric indicators of obesity: BMI (r = -0.64; P < .001), waist circumference (r = -0.59; P < .001), and body fat percentage (r = -0.64; P < .001) as well as with fasting plasma insulin (r = -0.35; P < .001) and homeostasis model assessment of insulin resistance (r = -0.35; P < .001). In conclusion, we observed a higher prevalence of vitamin D deficiency among obese participants and this was associated with a proatherogenic cardiometabolic risk profile.

Status of Vitamin-D in diabetic patients

BACKGROUND

Vitamin D (vit D) deficiency has been found to have an inverse relationship with the occurrence of type-2 diabetes mellitus (DM). The aim of this study was to assess the vit D level in type-2 diabetic patients.

METHODS

One hundred-twenty DM patients selected as case group and 120 healthy individuals as control group were investigated in this study from October 2011 to September 2012 in Shahid Beheshti and Ayatollah Rouhani teaching hospital in Babol, North of Iran. Both groups were matched regarding age and gender. Serum levels of 25(OH)-vitamin D were measured in both groups. The data were collected and analyzed.

RESULTS

The mean age of the case group was 51.2±7.98 and in control group was 50.6±7.73 years. The mean concentration of vit D in the case group was 18.7±10.2 and in the control group was 24.6±13.5 ng/dl (p=0.002). The mean concentration of vit D in male subjects in both groups were equal but in women with diabetes was lower than the healthy women (19.3±11.9 versus 27.03±10.28 ng/dl, respectively) (p=0.0001). In diabetic patient vit D level was deficient in 77 (64.2%), insufficient in 30 (25%) and sufficient in 13 (10.3%) patients. In the healthy group, these parameters were seen in 44 (36.6%), in 46 (38.4%) and in 30 (25%) patients.

CONCLUSION

The results show that vit D concentration was significantly lower in diabetic patients than the healthy individuals. Although the mean concentration of vit D in males in both groups was equal but in the women with diabetes was lower than the healthy women.

Biomolecular basis of the role of diabetes mellitus in osteoporosis and bone fractures

Osteoporosis has become a serious health problem throughout the world which is associated with an increased risk of bone fractures and mortality among the people of middle to old ages. Diabetes is also a major health problem among the people of all age ranges and the sufferers due to this abnormality increasing day by day. The aim of this review is to summarize the possible mechanisms through which diabetes may induce osteoporosis. Diabetes mellitus generally exerts its effect on different parts of the body including bone cells specially the osteoblast and osteoclast, muscles, retina of the eyes, adipose tissue, endocrine system specially parathyroid hormone (PTH) and estrogen, cytokines, nervous system and digestive system. Diabetes negatively regulates osteoblast differentiation and function while positively regulates osteoclast differentiation and function through the regulation of different intermediate factors and thereby decreases bone formation while increases bone resorption. Some factors such as diabetic neuropathy, reactive oxygen species, Vitamin D, PTH have their effects on muscle cells. Diabetes decreases the muscle strength through regulating these factors in various ways and ultimately increases the risk of fall that may cause bone fractures.

Decreased circulating 25-(OH) Vitamin D concentrations in obese female children and adolescents: positive associations with Retinol Binding Protein-4 and Neutrophil Gelatinase-associated Lipocalin

OBJECTIVE

Hypovitaminosis D has been associated with adult as well as childhood obesity. Retinol-binding-protein-4 (RBP-4) and Neutrophil Gelatinase-associated Lipocalin (NGAL) are altered in obese individuals. The aim of this study was to examine circulating 25-(OH) Vitamin D (25-(OH) D) concentrations according to BMI and its associations with RBP-4 and NGAL in female children and adolescents.

DESIGN

Seventy-nine (79) children, aged 8-16 years, were studied and divided into four groups: 19 control (BMI z-score range -2.15 - 1.24), 20 overweight (1.34 - 2.49), 20 obese (2.50 - 2.87) and 20 ultra-obese (3 - 4.37). Patients were derived from a Pediatric Obesity Clinic. Plasma 25-(OH) D, RBP-4 and NGAL concentrations were measured with specific assays.

RESULTS

Plasma 25-(OH) D concentrations were decreased significantly in the ultra-obese (p=0.005) and marginally in the obese group (p=0.05) compared to the control group. In the entire BMI range, Spearman correlations revealed strong positive associations between 25-(OH) D and RBP-4 (r=0.349, p=0.002) and between 25-(OH) D and NGAL (r=0.338, p=0.003).

CONCLUSIONS

25-(OH) D is deficient in a clinical population of obese female children and adolescents, whereas in the entire BMI range 25-(OH) D is associated with RBP4 and NGAL concentrations. Longitudinal studies are needed to reveal the role of these associations in metabolic alterations related to childhood and adolescent obesity and associated metabolic morbidities.