Type 2 Diabetes Mellitus, Insulin Resistance, and Vitamin D

Evaluation of the knowledge regarding vitamin D, and sunscreen use of female adolescents in Iran

BACKGROUND

Vitamin D (Vit D) deficiency/insufficiency is an important risk factor for several chronic conditions. We aimed to evaluate the knowledge and behavior of female adolescents with respect to the association between sunlight exposure, sunscreen use, and Vit D status.

METHODS

This cross-sectional survey was performed in northeastern Iran, among 940 female adolescents in January 2015. Each subject completed a questionnaire containing items about demographic characteristics, knowledge about Vit D and their use of sunscreen. Serum Vit D levels were measured using an electrochemiluminescence method and dietary intake of Vit D was assessed using a Food Frequency Questionnaire. Statistical analyses were conducted using SPSS software. A P value < 0.05 was considered statistically significant.

RESULTS

Few of the participants were aware of the biological functions of Vit D (8.8%), the causes of Vit D deficiency (16.7%), and the sources of Vit D (9.3%). Less than half of the participants used sunscreen during the day. The serum levels of Vit D in subjects who used sunscreen were significantly lower than those who did not (p = 0.004). However, there was no significant association between their knowledge about Vit D and serum Vit D, or dietary intake of Vit D.

CONCLUSION

There appears to be a lack of coherence between lifestyle, behavior and knowledge that may affect the Vit D status of adolescent girls in northeastern Iran. This information provides a basis for developing public health planning (workshops or training at the college level) for the prevention of Vit D deficiency especially in adolescent girls.

Serum Level of Vitamin D Is Associated with Severity of Coronary Atherosclerosis in Postmenopausal Women

Background: Postmenopausal women experience rapid progression of coronary artery disease. Vitamin D deficiency appears to be a modifiable risk factor for cardiovascular diseases. This study aimed to analyze the impact of 25-hydroxyvitamin D3 (25(OH)D) level on the severity of coronary atherosclerosis and its potential cardioprotective effect in postmenopausal women. Material and Methods: The study prospectively recruited 351 women in postmenopausal age undergoing coronary angiography. The severity of coronary atherosclerosis was assessed using the Coronary Artery Surgery Study Score (CASSS). A level of 25(OH)D was measured with electrochemiluminescence. Results: Women with more severe coronary atherosclerosis have significantly lower 25(OH)D serum level (p = 0.0001). Vitamin D (β = -0.02; p = 0.016), hypertension (β = 0.44; p = 0.025), age (β = 0.02; p = 0.003), and history of MI (β = 0.63; p < 0.0001), were shown as CASSS determinants. Age, hyperlipidemia, and history of MI were found to determine the level of vitamin D (all p < 0.05). Women with a three-vessel disease hospitalized due to ACS, with a history of MI, hyperlipidemia and hypertension presented the lowest vitamin D level. Conclusions: Our study showed that lower serum 25(OH)D in postmenopausal women is associated with more significant stenosis in the coronary arteries. Therefore, we suggest considering low vitamin D level as a potential risk factor for coronary artery disease.

Effect of omega-3 and vitamin D co-supplementation on psychological distress in reproductive-aged women with pre-diabetes and hypovitaminosis D: A randomized controlled trial

PURPOSE

Psychological distresses and pre-diabetes are among the risk factors of developing type-II diabetes. The present study was conducted to determine the effectiveness of omega-3 and vitamin D co-supplementation on psychological distresses in women of reproductive age with pre-diabetes and hypovitaminosis D.

METHODS

The present factorial clinical trial was conducted on 168 women of reproductive age with pre-diabetes and hypovitaminosis D. These participants were selected by stratified random sampling and were assigned to four groups for 8 weeks: group 1 (placebo group), group 2 (omega-3 group), group 3 (vitamin D group), and group 4 (co-supplement group). The medication and placebo doses being two 1000-mg tablets each day for omega-3 and 50,000-IU pearls every 2 weeks for vitamin D. Fasting blood glucose and vitamin D were measured at the beginning of the study. The Depression Anxiety Stress Scale-21 and the Pittsburgh Sleep Quality Index were completed by the participants at the start and end of the intervention.

RESULTS

A significant difference was observed in terms of reduction in anxiety and improvement in sleep quality in the co-supplementation compared to the other three groups (p < .05). There was also a significant difference between the group receiving both supplements and the group receiving only placebos in terms of reduction in depression and stress (p < .05).

CONCLUSION

Vitamin D and omega-3 co-supplementation improved depression, anxiety, and sleep quality in women of reproductive age with pre-diabetes and hypovitaminosis D. Therefore, these two supplements can be recommended for improving the mental health of this group of women.

CLINICAL TRIAL REGISTRY

Iranian Registry of Clinical Trials Code: IRCT20100130003226N17. Registered on February 9, 2019.

High Fat Diet and High Cholesterol Diet Reduce Hepatic Vitamin D-25-Hydroxylase Expression and Serum 25-Hydroxyvitamin D3 Level through Elevating Circulating Cholesterol, Glucose, and Insulin Levels

SCOPE

Low circulating 25-hydroxyvitamin D (25(OH)D) levels associate with obesity, diabetes, and hyperlipidemia, but the underlying mechanisms remain uncertain. As energy-dense diet contributes to these disorders, this study investigates whether diet could impair vitamin D metabolism.

METHODS AND RESULTS

Compared with control chow-fed mice, high fat diet (HFD)-fed mice show lower serum 25(OH)D₃ and 1,25(OH)₂ D₃ levels, lower hepatic vitamin D 25-hydroxylase Cyp2r1 expression but comparable renal vitamin D metabolic enzymes expression. Time course studies show that after HFD feeding, the serum concentrations of cholesterol, triglycerides, fatty acids, glucose, and insulin elevate sequentially and before the reduction of hepatic Cyp2r1 expression and serum 25(OH)D₃ levels. Hepatic Cyp2r1 expression also reduces after consuming high fat and high sucrose diet. After high cholesterol diet feeding, serum total cholesterol rises and hepatic Cyp2r1 expression decreases ahead of the reduction of serum 25(OH)D₃ . In vitro studies demonstrate that high concentrations of cholesterol, glucose, and insulin significantly inhibit Cyp2r1expression in primary murine hepatocytes. Further studies show that dietary restriction in HFD-fed mice ameliorates hypercholesterolemia, hyperglycemia, and hypertriglyceridemia, and elevates hepatic Cyp2r1 expression and serum 25(OH)D₃ level.

CONCLUSION

These findings suggest that diet-induced elevation of circulating cholesterol, glucose, and insulin reduces serum 25(OH)D₃ level through suppressing hepatic Cyp2r1 expression.

Inverse Association between Serum 25-hydroxyvitamin D Levels and Risk of Suspected Non-Alcoholic Fatty Liver Disease in Obese Population

BACKGROUND

Worldwide, vitamin D deficiency is a public health issue and the prevalence of obesity and non-alcoholic fatty liver disease (NAFLD) are rapidly increasing. There are a limited number of studies assessing the association between serum levels of 25-hydroxyvitamin D (25(OH)D) and NAFLD risk in obese population.

OBJECTIVE

We evaluated the associations between serum 25(OH)D levels and risk of suspected NAFLD after stratification by obesity using data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2008-2014.

METHODS

This study included 25,755 subjects without significant alcohol consumption for the serum alanine aminotransferase (ALT) and hepatic steatosis index (HSI) analyses (8922 subjects for the serum gamma-glutamyl transferase (GGT) and fatty liver index (FLI) analyses), based on a cross-sectional study design. Serum 25(OH)D levels were measured using a Gamma counter with radioimmunoassay. A survey logistic regression model was applied to estimate ORs and 95% CIs. Restricted cubic smoothing splines were applied to evaluate nonlinear associations.

RESULTS

The risk of suspected NAFLD was reduced per unit of natural log-transformed serum 25(OH)D concentration in obese individuals (OR [95% (CI)]; for ALT, 0.80 [0.67, 0.96]; for GGT, 0.70 [0.49, 0.99; for FLI, 0.68 [0.47, 1.01]; for HSI, 0.70 [0.56, 0.87]). The ORs [95% CI] of suspected NAFLD changed across the quartiles: for serum ALT, from 1.02 [0.85, 1.23] to 0.72 [0.59, 0.87]; for serum GGT, from 0.79 [0.56, 1.13] to 0.64 [0.44, 0.92]; for FLI, from 0.98 [0.67, 1.44] to 0.70 [0.48, 1.02]; and for HSI, from 0.91 [0.73, 1.14] to 0.65 [0.52, 0.81] with dose-response relationships (all p for trend < 0.01).

CONCLUSIONS

This study suggests that vitamin D sufficiency for public health should be emphasized in order to prevent adverse health effects in obese populations.

Oral Microbiota: A Major Player in the Diagnosis of Systemic Diseases

The oral cavity is host to a complex and diverse microbiota community which plays an important role in health and disease. Major oral infections, i.e., caries and periodontal diseases, are both responsible for and induced by oral microbiota dysbiosis. This dysbiosis is known to have an impact on other chronic systemic diseases, whether triggering or aggravating them, making the oral microbiota a novel target in diagnosing, following, and treating systemic diseases. In this review, we summarize the major roles that oral microbiota can play in systemic disease development and aggravation and also how novel tools can help investigate this complex ecosystem. Finally, we describe new therapeutic approaches based on oral bacterial recolonization or host modulation therapies. Collaboration in diagnosis and treatment between oral specialists and general health specialists is of key importance in bridging oral and systemic health and disease and improving patients' wellbeing.

Effects of probiotics, prebiotics, and synbiotics on polycystic ovary syndrome: a systematic review and meta-analysis

This meta-analysis of randomized controlled trials (RCTs) was performed to summarize the effects of probiotics, prebiotics, and synbiotics on insulin resistance (IR), lipid profiles, anthropometric indices, and C-reactive protein (CRP) level for polycystic ovary syndrome (PCOS). We searched 8 databases from their inception until 1st October, 2020. The effect sizes were expressed as standardized mean difference (SMD) with 95% confidence intervals (95% CI). Subgroup analyses were undertaken for further identification of effects of probiotics, prebiotics, and synbiotics, based on the following aspects: (1) type of intervention (probiotics, prebiotics, or synbiotics); (2) study duration (≥ 12 weeks or < 12 weeks); (3) number of probiotic strains (multi strains or single strain); (4) probiotic dose (≥ 2 × 10⁸ colony-forming units [CFU] or < 2 × 10⁸ CFU). A total of 17 eligible RCTs with 1049 participants were included. Results showed that probiotic, prebiotic, and synbiotic intake decreased fasting plasma glucose (SMD, -1.35; 95% CI, -2.22 to -0.49; p = 0.002), fasting insulin (SMD, -0.68; 95% CI, -1.08 to -0.27; p = 0.001), homeostatic model of assessment for IR (SMD, -0.73; 95% CI, -1.15 to -0.31; p = 0.001), triglycerides (SMD, -0.85; 95% CI, -1.59 to -0.11; p = 0.024), total cholesterol (SMD, -1.09; 95% CI, -1.98 to -0.21; p = 0.015), low-density lipoprotein cholesterol (SMD, -0.84; 95% CI, -1.64 to -0.03; p = 0.041), very-low-density lipoprotein cholesterol (SMD, -0.44; 95% CI, -0.70 to -0.18; p = 0.001), and increased quantitative insulin sensitivity check index (SMD, 2.00; 95% CI, - 0.79 to 3.22; p = 0.001). However, probiotic, prebiotic, and synbiotic supplements did not affect anthropometric indices, high-density lipoprotein cholesterol, and CRP levels. Subgroup analysis showed that probiotic or prebiotic might be the optimal choice for ameliorating IR or lipid profiles, respectively. Additionally, the effect was positively related to courses and therapeutical dose. Overall, the meta-analysis demonstrates that probiotic, prebiotic, or synbiotic administration is an effective and safe intervention for modifying IR and lipid profiles.

Hsa_circ_0054633 association of C peptide is related to IL-17 and TNF-α in patients with diabetes mellitus receiving insulin treatment

Background

Chronic inflammation damaged the islet and resulted in dysfunction of T2D. Circular RNA is stable and better for biomarker in many diseases. Here, we aimed to identify potential circular RNA hsa_circ_0054633 that can be a biomarkers for the effects of insulin therapy in T2D.

Methods

In this retrospective case‐control study, patients were from Li Huili Hospital, Ningbo, China, from February 10, 2019, to August 15, 2019. We included 47 healthy adults, 46 new‐onset T2D with insulin resistance, and 51 patients with insulin therapy. Serum inflammation factors were tested by ELISA assays. We selected hsa_circ_0054633 as a candidate biomarker and measured its concentration in serum by qRT‐PCR. The Pearson correlation test was used to evaluate the correlation between this circRNA and clinical variables.

Results

Clinical data indicated that serum C peptide was increased in T2D treatment with insulin. Serum hsa_circ_0054633 was decreased in insulin treatment group. Hsa_circ_0054633 was negative correlated with C peptide (r = −0.2841, p = 0.0433,). IL‐1 and IL‐6, IL‐17, and TNF‐α were higher in T2D patients and decreased after insulin treatment, only IL‐17 and TNF‐α showed a positive correlation to hsa_circ_0054633 (r = 0.4825, p < 0.0001, and r = 0.6190, p < 0.0001). The area under ROC curve was 0.7432, 0.5839, and 0.7573 for Hsa_circ_0054633, C peptide, and their combination.

Conclusion

Hsa_circ_0054633 level was lower in T2D with insulin treatment than untreated and was a negative correlation with C peptide, and positively correlated with IL‐17 and TNF‐α, suggesting that hsa_circ_0054633 may be a potential early indicator of insulin treatment effect to improve inflammation condition.

The impact of metformin on hypothalamic-pituitary-thyroid axis activity in postmenopausal women with untreated non-autoimmune subclinical hypothyroidism

Metformin was found to reduce elevated thyrotropin levels in subjects with hypothyroidism. The impact on thyrotropin levels was stronger in women receiving oral contraceptive pills than in women not using any contraception. The aim of the present study was to determine whether physiological levels of oestradiol determine the effect of metformin on hypothalamic-pituitary-thyroid axis activity. The study population included 40 postmenopausal women with prediabetes and untreated non-autoimmune subclinical hypothyroidism, using (group A; n = 18) or not using (group B; n = 22) oestradiol replacement therapy. Over the entire study periods, all subjects were treated with metformin (2.55-3.00 g daily). Plasma levels of glucose, lipids, insulin, thyrotropin, free thyroxine, free triiodothyronine, prolactin, gonadotropins and oestradiol were measured, while the structure parameters of thyroid homeostasis and the degree of insulin sensitivity were calculated at the beginning of the study and 6 months later. At entry, both groups differed in gonadotropin and oestrogen levels. Despite improving insulin sensitivity, thyrotropin levels and Jostel's thyrotropin index in both study groups, these effects were stronger in group A than group B. Only in group A, metformin increased SPINA-GT, while only in group B the drug decreased FSH levels. Levels of the other variables remained at a similar level throughout the study. The effect of treatment on thyrotropin levels correlated with its baseline values, as well as with the improvement of insulin sensitivity. The results obtained suggest that the impact of metformin on hypothalamic-pituitary-thyroid axis activity depends on the oestrogen status of patients.

Vitamin D status determines the impact of metformin on circulating prolactin levels in premenopausal women

WHAT IS KNOWN AND OBJECTIVE

Metformin was found to normalize secretory function of overactive pituitary cells. Its effect on circulating thyrotropin levels was more pronounced in women receiving exogenous vitamin D. The aim of the current study was to investigate whether vitamin D status determines the impact of metformin on prolactin levels in premenopausal women with hyperprolactinaemia.

METHODS

The study population consisted of three groups of women with prediabetes and elevated prolactin levels: vitamin D-naïve women with vitamin D insufficiency (group 1; n = 19), women receiving vitamin D preparations because of vitamin D deficiency (group 2 n = 20), as well as vitamin D-naïve women with normal vitamin D status (group 3 n = 23). All participants were then treated with metformin (2.55-3 g daily). Circulating levels of glucose, insulin, prolactin, thyrotropin, free thyroid hormones, gonadotropins, estradiol, calcium and 25-hydroxyvitamin were determined at baseline and six months later.

RESULTS AND DISCUSSION

At baseline, prolactin levels were higher in group 1 than in the remaining groups of patients. Although metformin decreased glucose levels and improved insulin sensitivity in all treatment groups, this effect was more pronounced in groups 2 and 3. Only in subjects with 25-hydroxyvitamin D levels within the reference range, metformin reduced prolactin levels. The impact on prolactin levels correlated with 25-hydroxyvitamin D levels and with the improvement in insulin sensitivity. The drug produced a neutral effect on circulating levels of thyrotropin, free thyroid hormones, gonadotropins, estradiol, calcium and 25-hydroxyvitamin D.

WHAT IS NEW AND THE CONCLUSION

The results of the current study suggest that the impact of metformin on secretory function of overactive lactotropes depends on the vitamin D status of patients.

Double-Edged Sword of Vitamin D3 Effects on Primary Neuronal Cultures in Hypoxic States

The use of vitamin D3 along with traditional therapy opens up new prospects for increasing the adaptive capacity of nerve cells to the effects of a wide range of stress factors, including hypoxia-ischemic processes. However, questions about prophylactic and therapeutic doses of vitamin D3 remain controversial. The purpose of our study was to analyze the effects of vitamin D3 at different concentrations on morpho-functional characteristics of neuron-glial networks in hypoxia modeling in vitro. We showed that a single administration of vitamin D3 at a high concentration (1 µM) in a normal state has no significant effect on the cell viability of primary neuronal cultures; however, it has a pronounced modulatory effect on the functional calcium activity of neuron-glial networks and causes destruction of the network response. Under hypoxia, the use of vitamin D3 (1 µM) leads to total cell death of primary neuronal cultures and complete negation of functional neural network activity. In contrast, application of lower concentrations of vitamin D3 (0.01 µM and 0.1 µM) caused a pronounced dose-dependent neuroprotective effect during the studied post-hypoxic period. While the use of vitamin D3 at a concentration of 0.1 µM maintained cell viability, preventive administration of 0.01 µM not only partially preserved the morphological integrity of primary neuronal cells but also maintained the functional structure and activity of neuron-glial networks in cultures. Possible molecular mechanisms of neuroprotective action of vitamin D3 can be associated with the increased expression level of transcription factor HIF-1α and maintaining the relationship between the levels of BDNF and TrkB expression in cells of primary neuronal cultures.

Swietenine potentiates the antihyperglycemic and antioxidant activity of Metformin in Streptozotocin induced diabetic rats

Diabetes mellitus or type-2 diabetes, commonly referred as diabetes, is a metabolic disorder that results in high blood sugar level. Despite the availability of several antidiabetic drugs in the market, they still do not adequately regulate blood sugar levels. Thus, in general people prefer to use herbal supplements/medicines along with antidiabetic drugs to control blood sugar levels. One of such herbal medicine is Swietenia macrophylla seeds. It is widely used in Asia for controlling blood sugar levels. One of the major bioactive compounds, Swietenine, is reported to be responsible for controlling blood glucose levels. However, there were no studies on its efficacy in controlling the blood glucose in diabetic rats. In this study, we evaluated the antihyperglycemic activity of Swietenine and its pharmacodynamic interaction with Metformin in Streptozotocin induced diabetes in rats. The activity of Swietenine was investigated at three different doses: 10, 20 and 40 mg/kg body weight (bw). Metformin (50 mg/kg bw) was used as a standard drug. Swietenine (20 and 40 mg/kg bw) and Metformin (50 mg/kg bw) showed significant effect in reducing the glucose, cholesterol, triglycerides, low-density lipoprotein, urea, creatinine, alanine transaminase, alkaline phosphatase, aspartate transaminase, alanine transaminase, and malondialdehyde level in serum while it had increased the high-density lipoprotein, glutathione, and total antioxidant capacity level. In addition, Swietenine (20 and 40 mg/kg) had shown significant synergistic effect with Metformin. Administration of Swietenine at 10 mg/kg bw neither showed activity nor influenced Metformin's activity. The results from this study confirmed the beneficial effects of Swietenine and its synergistic action with Metformin in controlling the dysregulated serum parameters in Streptozotocin induced diabetes in rats.

Vitamin D Status is Independently Associated with Insulin Resistance in Patients with Type 2 Diabetes Mellitus

Purpose

This study aimed to examine whether 25-hydroxyvitamin D (25OHD) levels (an indicator of vitamin D status) are independently associated with insulin resistance (IR) in patients with type 2 diabetes mellitus (T2DM).

Patients and Methods

This was a cross-sectional study. Participants with T2DM were recruited from the Department of Endocrinology in Hebei General Hospital according to inclusion and exclusion criteria. Data on basic characteristics and blood parameters were collected. We used the IR index (20/[fasting C-peptide × fasting plasma glucose]) to evaluate IR. Potential confounding factors were selected from comparisons among different IR index groups of quartiles and were adjusted in different models.

Results

We included 172 subjects (121 men and 51 women) whose mean age was 53.2±10.6 years. Body mass index (BMI), DM course, insulin use, glycated hemoglobin (HbA1c), fasting blood glucose, fasting C-peptide, triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), apolipoprotein A1 (ApoA1), and albumin were differed among different IR-index groups (all P value <0.05). In models 1 and 2, no or some confounding factors were adjusted for, and we found that there was no relationship between 25OHD and the IR index. In model 3, when all confounding factors (DM course, insulin use, BMI, HbA1c, TG, HDL-C, ApoA1, albumin and other bone turnover markers) were adjusted for, the IR index was increased by 5.6% when 25OHD levels increased by 1 ng/mL (odds ratio: 1.056; 95% confidence interval: 1.009, 1.105).

Conclusion

Vitamin D is independently associated with IR in patients with T2DM.

Vitamin D and new insights into pathophysiology of type 2 diabetes

Deficiency in vitamin D plays a role in the onset and development of insulin resistance (IR) and type 2 diabetes (T2DM). A normal level of vitamin D is able to reduce low grade inflammation, which is a major process in inducing insulin resistance. It is also engaged in maintaining low resting levels of reactive species and radicals, normal Ca²⁺ signaling, a low expression of pro-inflammatory cytokines but increased formation of anti-inflammatory cytokines. Vitamin D is also able to prevent hypermethylation (of DNA) and consequent functional inactivation of many genes, as well as other epigenetic alterations in β cells and in other insulin-sensitive peripheral tissues, mainly liver, adipose tissue and muscle. Vitamin D deficiency thus belongs to key factors accelerating the development of IR and consequently T2DM as well. However, vitamin D supplementation aimed at the control of glucose homeostasis in humans showed controversial effects. As a result, further studies are running to gain more detailed data needed for the full clinical utilization of vitamin D supplementation in the prevention and treatment of T2DM. Until new results are published, supplementation with high doses of vitamin D deficiency is not recommended. However, prevention of vitamin D deficiency and its correction are highly desired.

Effects of long-term vitamin D and n-3 fatty acid supplementation on inflammatory and cardiac biomarkers in patients with type 2 diabetes: secondary analyses from a randomised controlled trial

AIMS/HYPOTHESIS

Interventions that reduce inflammation may delay progression of microvascular and macrovascular complications in diabetes. We examined the effects of vitamin D₃ and/or n-3 fatty acid supplementation vs placebo on 5 year changes in serum inflammatory and cardiac biomarkers in adults with type 2 diabetes.

METHODS

This study reports pre-specified secondary outcomes of the Vitamin D and Omega-3 Trial to Prevent and Treat Diabetic Kidney Disease, in which 1312 US adults with type 2 diabetes and without known cardiovascular disease, malignancy, or end-stage kidney disease were randomised using computer-generated random numbers in blocks of eight to vitamin D₃ (2000 IU/day) vs placebo and n-3 fatty acids (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]; 1 g/day) vs placebo in a 2 × 2 factorial design. Participants, examiners, and researchers assessing outcomes were blinded to intervention assignment. We measured serum IL-6, high-sensitivity C-reactive protein (hsCRP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) at baseline and after 2 and 5 years.

RESULTS

A total of 333 participants were randomised to vitamin D₃ and placebo n-3 fatty acids, 289 to n-3 fatty acids and placebo vitamin D₃, 370 to vitamin D₃ and n-3 fatty acids, and 320 to 2 placebos; 989 (75%) and 934 (71%) participants returned blood samples at 2 and 5 years, respectively. Participants had a mean age of 67.6 years (46% women). Overall, baseline geometric means of IL-6, hsCRP and NT-proBNP were 1.2 pg/ml, 1.9 mg/l and 262 ng/l, respectively. After 5 years, mean IL-6 and hsCRP remained within 6% of their baseline values while mean NT-proBNP increased by 55% overall. Compared with placebo, participants assigned to vitamin D₃ had a 1.24-fold greater increase in NT-proBNP over 5 years (95% CI 1.09, 1.41; p = 0.003), while IL-6 and hsCRP did not have a significant difference in change. Comparing n-3 fatty acids with placebo, there was no significant difference in change in IL-6, hsCRP or NT-proBNP. No heterogeneity was observed in subgroup analyses accounting for baseline eGFR, urine albumin to creatinine ratio, initial biomarker concentration, 25-hydroxyvitamin D level or EPA+DHA index.

CONCLUSIONS/INTERPRETATION

Among adults with type 2 diabetes, supplementation with vitamin D₃ or n-3 fatty acids did not reduce IL-6, hsCRP or NT-proBNP over 5 years.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01684722 FUNDING: The study was funded by grant R01DK088762 from the National Institute of Diabetes and Digestive and Kidney Diseases. Graphical abstract.

1α,25-Dihydroxyvitamin D3 ameliorates diabetes-induced bone loss by attenuating FoxO1-mediated autophagy

Autophagy is vital for maintaining cellular homeostasis through removing impaired organelles. It has recently been found to play pivotal roles in diabetes mellitus (DM), which is associated with increased bone fracture risk and loss of bone density. However, the mechanism whereby autophagy modulates DM-induced bone loss is not fully elucidated. Previous work has shown that 1α,25-Dihydroxyvitamin D3 (1,25D) exerts positive effects on autophagy, thus affecting bone metabolism. Here, we investigated whether autophagy was involved in the regulation of diabetic bone metabolism. Using Micro-CT, Elisa, histology, and histomorphometry analysis, we demonstrated that 1,25D rescues glucose metabolism dysfunction and ameliorates bone loss in diabetic mice. In vitro, 1,25D alleviated primary osteoblast dysfunction and intracellular oxidative stress through reducing prolonged high-glucose-mediated excessive autophagy in primary osteoblasts, reflected by decreased protein level of Beclin1 and LC3. Of note, the autophagy activator rapamycin (RAP) ablated the positive effects of 1,25D in diabetic environment, leading to a marked increase in autolysosomes and autophagosomes, examined by mRFP-GFP-LC3 fluorescence double labeling. The excessive autophagy induced by high glucose was deleterious to proliferation and differentiation of primary osteoblasts. Additionally, biochemical studies identified that PI3K/Akt signaling could be activated by 1,25D, resulting in the inhibition of FoxO1. We confirmed that FoxO1 deficiency alleviated high-glucose-induced autophagy and improved biological functions of primary osteoblasts. Together, our results suggest that the PI3K/Akt/FoxO1 signaling pathway is involved in the osteoprotective effect of 1,25D by attenuating autophagy in diabetes, providing a novel insight for the prevention and treatment of diabetes-caused bone loss.

Association between Gene Polymorphisms of Vitamin D Receptor and Gestational Diabetes Mellitus: A Systematic Review and Meta-Analysis

(1) Background: Studies on the association between Vitamin D receptor gene polymorphism and gestational diabetes mellitus have been inconsistent. The aim of this study was to summarize available evidence on the association between polymorphisms of Vitamin D receptor genes and susceptibility to gestational diabetes mellitus. (2) Methods: We searched databases of PubMed, Web of Science, Embase, China national knowledge infrastructure (CNKI), China science and technology journal database (VIP), and Wanfang Data for relevant articles. A systematic review and a meta-analysis were done to compare the distribution of Vitamin D receptor gene polymorphisms in gestational diabetes mellitus patients with those in controls using allelic, codominant, dominant, and recessive models. (3) Results: A total of eight eligible articles were included in the systematic review and of them, six articles were included in the meta-analysis. The vitamin D receptor gene rs7975232 polymorphism was associated with gestational diabetes mellitus under the allelic model (odds ratio = 1.28, 95% confidence interval 1.06–1.56), codominant model (CC vs. AA odds ratio = 1.97, 95% confidence interval 1.28–3.05), and recessive model (odds ratio = 1.83, 95% confidence interval 1.27–2.64) in the case of low heterogeneity. High heterogeneity existed in studies on the association of vitamin D receptor genes rs1544410, rs2228570, and rs731236 with gestational diabetes mellitus, and the most common sources of heterogeneity were the year of publication and matching. (4) Conclusion: Polymorphism of the vitamin D receptor gene rs7975232 may be associated with risk of developing gestational diabetes mellitus. Future studies should be designed to include standardized data collection and matching for important confounding factors such as body mass index, age, and race.

Vitamin D Deficiency in End Stage Renal Disease Patients with Diabetes Mellitus Undergoing Hemodialysis

Objectives: To assess the association of hypovitaminosis D with diabetes mellitus (DM) in patients with end stage renal disease (ESRD) undergoing hemodialysis.

Methodology: This cross-sectional study was conducted at the Jinnah Postgraduate Medical Centre between July 2019 and February 2020. Patients with diagnosed ESRD who were on hemodialysis, with or without concomitant DM were registered. Vitamin D levels were categorized according to the severity of the deficiency or excess as 0-10 ng/mL, severely deficient; 11-20 ng/mL, deficient; 21-32 ng/mL; insufficient, 33-49 ng/mL, adequate; 50-65 ng/mL, optimum; and above that as high. Patients were stratified according to the status of DM. 

Results: In a total of 80, the mean age was 45.21±12.67 years with 51 (63.75%) males and 29 (36.25%) females. A total of 36 (45%) CKD patients had concomitant diabetes. The median vitamin D levels were 20.25ng/mL. It was found that chronic kidney disease (CKD) patients with concomitant DM had significantly lower levels of vitamin D [15.19±6.83 vs. 30.28±14.22 (p<0.001)]. Out of the 12 patients with a severe deficiency, three-fourths of the population had DM as comorbidity, while in those with ‘deficiency’, 19 (67.9%) had DM. The majority of the patients without DM had adequate or optimum levels of serum 25-hydroxyvitamin D levels.

Conclusion: Current study indicated that deficiency of serum vitamin D is associated with concomitant DM in patients with CKD as the majority had a severe deficiency of serum 25(OH)D. Supplemental vitamin D may help correct the deficiency and prevent the associated complications in patients.

Obese Older Type 2 Diabetes Mellitus Patients with Muscle Insulin Resistance Benefit from an Enriched Protein Drink during Combined Lifestyle Intervention: The PROBE Study

(1) Background: Recent research showed that subtypes of patients with type 2 diabetes may differ in response to lifestyle interventions based on their organ-specific insulin resistance (IR). (2) Methods: 123 Subjects with type 2 diabetes were randomized into 13-week lifestyle intervention, receiving either an enriched protein drink (protein+) or an isocaloric control drink (control). Before and after the intervention, anthropometrical and physiological data was collected. An oral glucose tolerance test was used to calculate indices representing organ insulin resistance (muscle, liver, and adipose tissue) and β-cell functioning. In 82 study-compliant subjects (per-protocol), we retrospectively examined the intervention effect in patients with muscle IR (MIR, n = 42) and without MIR (no-MIR, n = 40). (3) Results: Only in patients from the MIR subgroup that received protein+ drink, fasting plasma glucose and insulin, whole body, liver and adipose IR, and appendicular skeletal muscle mass improved versus control. Lifestyle intervention improved body weight and fat mass in both subgroups. Furthermore, for the MIR subgroup decreased systolic blood pressure and increased VO2peak and for the no-MIR subgroup, a decreased 2-h glucose concentration was found. (4) Conclusions: Enriched protein drink during combined lifestyle intervention seems to be especially effective on increasing muscle mass and improving insulin resistance in obese older, type 2 diabetes patients with muscle IR.

The correlation between proinsulin, true insulin, proinsulin: True insulin ratio, 25(OH) D3, waist circumference and risk of prediabetes in Hainan Han adults

Purpose

Diabetes mellitus is a kind of highly prevalent chronic disease in the world. The intervention measures on the risk factors of prediabetes contribute to control and reduce the occurrence of diabetes. This study aimed to investigate the correlation between proinsulin (PI), true insulin (TI), PI/TI, 25(OH) D3, waist circumference (WC), and risk of prediabetes.

Methods

In this cross-sectional study, 1662 subjects including 615 prediabetes and 1047 non-prediabetes were recruited. Spearman’s correlation analysis was used to explore the association of PI, TI, PI/TI, 25(OH) D3, and waist circumference with prediabetes. Odds ratios (OR) and 95% confidence intervals (CI) were calculated by logistic regression. Receiver-Operator Characteristic (ROC) curve was used to evaluate the risk of prediabetes.

Results

Our study showed that FPI, 2hPI, FTI, 2hTI, FPI/FTI, and WC could enhance the risk of prediabetes (OR 1.034; OR 1.007; OR 1.005; OR 1.002; OR 3.577, OR 1.053, respectively; all p< 0.001). Stratified analyses indicated that FPI/FTI associated with an increased risk of prediabetes in men (OR 2.080, p = 0.042). FTI have a weak association with prediabetes risk in men and women (OR 0.987, p = 0.001; OR 0.994, p = 0.004, respectively). 2hPI could decrease prediabetes in women (OR 0.995, p = 0.037). Interesting, the sensitivity (86.0%) and AUC (0.942, p< 0.001) of combination (FPI+FTI+2hPI+2hTI+25(OH) D3+WC) were higher than the diagnostic value of these alone diagnoses. The optimal cutoff point of FPI, FTI, 2hPI, 2hTI, 25(OH) D3, and WC for indicating prediabetes were 15.5 mU/l, 66.5 mU/l, 71.5 mU/l, 460.5 mU/l, 35.5 ng/ml, and 80.5 cm, respectively. What’s more, the combination (FPI+FTI+2hPI+2hTI+25(OH) D3+WC) significantly improved the diagnostic value beyond the alone diagnoses of prediabetes in men and women (AUC 0.771; AUC 0.760, respectively).

Conclusion

The FPI, 2hPI, FTI, 2hTI, FPI/FTI, and WC significantly associated with an increased risk of prediabetes. The combination of FPI, FTI, 2hPI, 2hTI, 25(OH) D3, and WC might be used as diagnostic indicators for prediabetes.

Vitamin D levels, prediabetes risk and hemoglobin A1c levels in young non-diabetic Saudi women

AIMS/INTRODUCTION

Vitamin D levels are negatively correlated with prediabetes risk and hemoglobin A1c levels in individuals with prediabetes. The data are, however, scarce and inconsistent among different populations. We aimed to assess the association of vitamin D with prediabetes risk and hemoglobin A1c levels in young Saudi women with normoglycemia and prediabetes.

MATERIALS AND METHODS

We analyzed the data of individuals without diabetes (without diabetes history and hemoglobin A1c <6.4%) from the Princess Nourah bint Abdulrahman University's non-communicable diseases student registry. Demographic data, anthropometric and blood pressure measurements, and hemoglobin A1c and vitamin D results were retrieved and analyzed.

RESULTS

In total, 345 participants were included in the analysis. The prediabetes status showed no association with vitamin D levels, but it was significantly associated with the participants' weight and body mass index. Additionally, there was no correlation between the levels of vitamin D and hemoglobin A1c across the whole population, even after correction for body mass index. However, in the body mass index subgroups, when individuals with potentially harmful levels of vitamin D (>125 nmol/L) were excluded, a positive association was detected between vitamin D and hemoglobin A1c levels in the underweight individuals. Hemoglobin A1c values showed a positive correlation only with bodyweight and body mass index.

CONCLUSIONS

Vitamin D levels did not predict prediabetes status and showed no correlation with hemoglobin A1c levels in this population. Vitamin D levels' effect on the risk of prediabetes might be small compared with other well-established risk factors, such as obesity.

Study on the levels of 25(OH)D, inflammation markers and glucose and fat metabolism indexes in pregnant women of Han nationality in Jiangsu province with gestational diabetes mellitus

The aim of this study is to investigate the levels of 25(OH)D, inflammation markers and glucose and fat metabolism indexes in pregnant women with Gestational diabetes mellitus (GDM).One hundred and ten cases GDM and 100 cases healthy pregnant women in the First People's Hospital of Lianyungang City from October 2016 to December 2018 were recruited for this observational cross-sectional study. Each participant's anthropometric and demographic data was recorded. Blood samples were collected and analyzed to determine the levels of 25(OH)D, high sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-α), fasting blood glucose, fasting blood insulin, hemoglobin A1c (HbA1c), homeostasis model assessment of insulin resistance (HOMA-IR), cholesterol and triglycerides.Inflammatory markers and glucose and fat metabolism indexes were all significantly higher in the GDM group than that in the control group, while Serum 25(OH)D level in the GDM group was significantly lower. Serum 25(OH)D levels were negatively correlated with hs-CRP, while not with TNF-α. Furthermore, Serum 25(OH)D, hs-CRP and TNF-α levels were all associated with increased risk of developing GDM.Nowadays, the reports on the association between 25(OH)D level and GDM were controversial. Our results are consistent with the view that there was association between 25(OH)D level and GDM, and expand the literature by showing the roles of 25(OH)D, inflammation markers as well as glucose and fat metabolism indexes in the risk of developing GDM in the pregnant women with the low overall levels of 25(OH)D before delivery. This broadens our knowledge on the pathophysiology of GDM, which may be helpful in prevention and treatment of GDM.

A Single Large Dose of Vitamin D Could be Used as a Means of Coronavirus Disease 2019 Prevention and Treatment

There is no specific and effective medication for coronavirus disease 2019 (COVID-19), and avaccine is not available in recent months. Here, we hypothesize that a single large dose of vitamin D (Vit D) could be an option for trial in COVID-19. Vit D deficiency or insufficiency is very common in the general population as well as in patients with COVID-19. It has been shown that low Vit D level is associated with viral infection, and Vit D supplementation is beneficial for people infected with viruses, such as HIV and hepatitis C virus. Although COVID-19 is a respiratory disease, the morbidity and mortality of this disease are driven by coagulopathy. Clinical studies have shown that Vit D can exert anticoagulant effects. Vit D, a lipid-soluble vitamin, can be administered as a draught. Vit D supplementation is safe and has rare toxic events. In addition, the cost of Vit D is fairly low. Based on these observations, we speculate that a single dose of 300,000 IU Vit D may have a role in the prevention and treatment of COVID-19.

N1-Methylnicotinamide Improves Hepatic Insulin Sensitivity via Activation of SIRT1 and Inhibition of FOXO1 Acetylation

OBJECTIVE

To explore the effects of N¹-methylnicotinamide (MNAM) on insulin resistance and glucose metabolism in obese type 2 diabetes mellitus (T2DM) mice and regulatory mechanisms of the NAD-dependent deacetylase sirtuin-1 (SIRT1)/forkhead box protein O1 (FOXO1) pathway.

METHODS

Blood glucose and insulin levels were examined in mice. HE and oil red O staining were used to observe the effects of MNAM on liver lipid deposition in ob/ob mice. Real-time PCR and Western blotting were used to detect expression of gluconeogenesis, insulin signaling-related proteins, and SIRT1/FOXO1 pathway-related proteins. L-O2 cells were cultured as a model of insulin resistance, and MNAM and SIRT1 inhibitors were administered in vivo. Residual glucose and insulin signaling-related proteins were detected and the mechanisms associated with the SIRT1/FOXO1 signaling pathway in insulin resistance explored.

RESULTS

MNAM can effectively reduce levels of fasting blood glucose and insulin, improve liver morphology, and reduce lipid accumulation in obese type 2 diabetes mellitus mice. MNAM also downregulates the key proteins in the gluconeogenesis pathway in the liver, upregulates Sirt1 expression, and reduces acetylation of the FOXO1 protein. In vitro, MNAM could promote the glucose uptake capacity of L-O2 cells induced by palmitic acid (PA), a saturated fatty acid that induces IR in various scenarios, including hepatocytes, improving insulin resistance. As Sirt1 expression was inhibited, the reduction of hepatocyte gluconeogenesis and the regulation of the insulin signaling pathway by MNAM were reversed.

CONCLUSION

MNAM activates SIRT1 and inhibits acetylation of FOXO1, which in turn regulates insulin sensitivity in type 2 diabetic mice, leading to a reduction of hepatic glucose output and improvement of insulin resistance.

The Relationship Between Vitamin D Deficiency and Glycated Hemoglobin Levels in Patients with Type 2 Diabetes Mellitus

PURPOSE

The aims of this study were to determine the relationship between 25-hydroxyvitamin D [25(OH) D] and glycated hemoglobin (HbA1c) levels in male and female patients with type 2 diabetes mellitus (T2DM).

PATIENTS AND METHODS

The participants were adults diagnosed with T2DM recruited from Hebei General Hospital. Patient information and information regarding blood indicators were collected. The subjects were divided into no vitamin D deficiency group [25(OH) D >20 ng/mL] and vitamin D deficiency group [25(OH) D <20 ng/mL], and these groups were then further subdivided into male-only or female-only subgroups. And then, the subjects were divided into male group and female group in different 25(OH) D levels.

RESULTS

HbA1c levels in the vitamin D deficiency group were significantly higher than those in the no vitamin D deficiency group for all subjects. The same was true for female patients but not for male patients. There was no difference in HbA1c levels between male and female patients with T2DM, regardless of 25(OH) D deficiency. A negative correlation existed between 25(OH) D and HbA1c in all subjects, as well as in the male-only and female-only subgroups. Vitamin D deficiency was associated with high HbA1c levels before and after adjusting for confounding factors in all participants and in the female-only subgroup, but not in the male-only subgroup.

CONCLUSION

This study confirmed that vitamin D deficiency was related with high HbA1c levels in patients with T2DM, and this relationship differs between female and male patients.

MMP-2 salivary activity in type 2 diabetes mellitus patients

BACKGROUND

Type 2 diabetes mellitus (T2DM) and periodontitis are chronic inflammatory diseases with a bidirectional relationship. The uncontrolled levels of glucose in T2DM patients change the pathophysiology and balance of inflammatory mediators. Matrix Metalloproteinase-2 (MMP-2) is a zinc-dependent endopeptidase that is responsible for tissue remodeling and degradation of the extracellular matrix in periodontal tissue. Therefore, the uncontrolled levels of glucose in T2DM could lead to an imbalance in MMP-2 activity in saliva, favoring the development of periodontitis.

METHODS

Ninety-seven T2DM patients from Hospital Dr. Donato Alarcon were included in the study. Following clinical examination, the patients were classified into four groups according to the presence and degree of periodontal disease and glycemic control. Blood and whole saliva samples (WSS) were collected from each patient. Blood samples were used for Hba1c and polymorphonuclear cells count determination, while WSS were used to determine MMP-2 activity, TIMP-1 and nitrite. MMP-2 activity was determined by zymography. TIMP-1 were determined by Western blotting, and nitric oxide (NO) levels were determined by the Griess method.

RESULTS

Of the 97 patients with T2DM, 66 had periodontitis of different severities: 18 patients had mild periodontitis, 15 had moderate and 33 had severe. Salivary MMP-2 activity, HbA1c and TIMP-1 were positively correlated with the severity of periodontitis. On the other hand, the increase in HbA1c was negatively correlated with MMP-2 activity and quantity of TIMP-1 but was positively correlated with nitrite levels.

CONCLUSIONS

T2DM with glycemic uncontrol conditions, distinct clinical alterations in periodontal tissue were identified, including a decrease in the gingival redness, increased the clinical attachment loss and imbalance of MMP-2/TIMP-1, as the possible causes of disorders promoting the progression of periodontitis. Accelerated periodontitis development with poor glycemic uncontrol likely results from the altered response of host defenses and decreased activity of polymorphonuclear cells. Taken together, these findings identify MMP-2 as a promising molecular market for periodontitis.