Vitamin D status in youth with type 1 and type 2 diabetes enrolled in the Pediatric Diabetes Consortium (PDC) is not worse than in youth without diabetes

A review of dairy food intake for improving health among black children and adolescents in the US

Adequate nutrition during childhood and adolescence is crucial for proper neurological, musculoskeletal, immunological, and cardiometabolic health and development. Yet, disparities among socially underserved racial/ethnic groups in the United States (US) provide significant challenges to achieving adequate nutrition during these years of rapid growth and maturation. For example, Black children and adolescents are at greater risk for having food insecurity, lower-quality diets, obesity, and numerous associated health challenges that result from these disparities compared to their White peers. A growing body of evidence indicates that improving diet quality is critical for improving childhood and adolescent health and well-being, and that the diverse nutritional profile and bioactive compounds found within dairy foods may play multiple roles in promoting proper growth and development during these life stages. Therefore, to support overall health and development among Black youth, greater education and implementation efforts are needed to help this population meet the national dietary recommendations of 2.5 to 3 servings of dairy foods per day. Continuing to fall short of these recommendations puts Black children and adolescents at risk of multiple nutrient inadequacies and health disparities that can have lifelong impacts on disease development, mental health, and quality of life. This review presents the state of knowledge on health disparities and modifiable nutritional strategies involving milk and dairy foods to support the growth and maturation of children and adolescents, with a special focus on Black youth in the US.

Serum 25-Hydroxyvitamin D Levels and Youth-Onset Type 2 Diabetes: A Two-Sample Mendelian Randomization Study

Observational studies have linked vitamin D insufficiency to pediatric type 2 diabetes (T2D), but evidence from vitamin D supplementation trials is sparse. Given the rising prevalence of pediatric T2D in all ethnicities, determining the protective role of vitamin D has significant public health importance. We tested whether serum 25-hydroxyvitamin D (25OHD) levels are causally linked to youth-onset T2D risk using Mendelian randomization (MR). We selected 54 single-nucleotide polymorphisms (SNPs) associated with 25OHD in a European genome-wide association study (GWAS) on 443,734 individuals and obtained their effects on pediatric T2D from the multi-ethnic PRODIGY GWAS (3006 cases/6061 controls). We applied inverse variance weighted (IVW) MR and a series of MR methods to control for pleiotropy. We undertook sensitivity analyses in ethnic sub-cohorts of PRODIGY, using SNPs in core vitamin D genes or ancestry-informed 25OHD SNPs. Multivariable MR accounted for the mediating effects of body mass index. We found that a standard deviation increase in 25OHD in the logarithmic scale did not affect youth-onset T2D risk (IVW MR odds ratio (OR) = 1.04, 95% CI = 0.96-1.13, p = 0.35) in the multi-ethnic analysis, and sensitivity, ancestry-specific and multivariable MR analyses showed consistent results. Our study had limited power to detect small/moderate effects of 25OHD (OR of pediatric T2D < 1.39 to 2.1). In conclusion, 25OHD levels are unlikely to have significant effects on the risk of youth-onset T2D across different ethnicities.

Free and Bioavailable Vitamin D Levels of Patients with Type 1 Diabetes Mellitus and Association with Bone Metabolism

Aim

Vitamin D deficiency is known to be associated with metabolic bone diseases. The aim of this study is to evaluate vitamin D and calculated free and bioactive vitamin D levels of type 1 diabetic patients and to evaluate the association with bone turnover markers.

Method

This cross-sectional study includes 60 patients admitted to endocrinology outpatient clinic with diagnosis of type 1 diabetes mellitus and 60 controls. Weight, height and waist circumference were recorded and blood samples were taken for measurement of 25-hydroxyvitamin D (25(OH)D), vitamin D binding protein (VDBP), osteocalcin, bone alkaline phosphatase (bone-ALP), c-telopeptide. Free and bioavailable vitamin D levels were calculated with formula.

Results

Vitamin D levels of type 1 diabetic patients were significantly higher (p = 0.01). Parathormone levels of the group with vitamin D level under 20 ng/ml was significantly higher (p = 0.029). VDBP levels were similar in both groups. Correlation analysis of free and bioavailable vitamin D level with osteocalcin, c-telopeptide, bone alkaline phosphatase revealed only a weak significant correlation between free vitamin D and osteocalcin (r = -0.201; p = 0.028). A negative correlation was determined between 25(OH)D and parathormone levels (r = -0.294; p < 0.005). Serum osteocalcin, bone alkaline phosphatase and c-telopeptide levels of control group were significantly higher.

Conclusion

25(OH)D levels of the study population was extremely low. The measurement of VDBP and calculated free and bioactive vitamin D levels did not show a better correlation with bone turnover markers according to 25(OH)D levels.

Pathophysiological Role and Therapeutic Implications of Vitamin D in Autoimmunity: Focus on Chronic Autoimmune Diseases

Vitamin D is a pleiotropic secosteroid yielding multiple actions in human physiology. Besides the canonical regulatory activity on bone metabolism, several non-classical actions have been described and the ability of vitamin D to partake in the regulation of the immune system is particularly interesting, though far stronger and convincing evidence has been collected in in vitro as compared to in vivo studies. Whether vitamin D is able to regulate at physiological concentrations the human immune system remains unproven to date. Consequently, it is not established if vitamin D status is a factor involved in the pathogenesis of immune-mediated diseases and if cholecalciferol supplementation acts as an adjuvant for autoimmune diseases. The development of autoimmunity is a heterogeneous process, which may involve different organs and systems with a wide range of clinical implications. In the present paper, we reviewed the current evidences regarding vitamin D role in the pathogenesis and management of different autoimmune diseases.

Emerging role of vitamin D in autoimmune diseases: An update on evidence and therapeutic implications

Vitamin D plays a key role in in calcium homeostasis and, thus, provides an important support in bone growth by aiding in the mineralization of the collagen matrix. However, vitamin D performs various immunomodulatory, anti-inflammatory, antioxidant and anti-fibrotic actions. Autoimmune diseases result from an aberrant activation of the immune system, whereby the immune response is directed against harmless self-antigens. Does vitamin D play a role in the pathophysiology of autoimmune diseases? And, if so, what is its role? In the last decade, researchers' interest in vitamin D and its correlations with autoimmune diseases has considerably increased. We conducted a literature review, covering the period January 1, 2009 through March 30, 2019, in PubMed. We analyzed more than 130 studies in order to find a correlation between vitamin D levels and its effect upon several autoimmune diseases. The analysis demonstrated an inverse association between vitamin D and the development of several autoimmune diseases, such as SLE, thyrotoxicosis, type 1 DM, MS, iridocyclitis, Crohn's disease, ulcerative colitis, psoriasis vulgaris, seropositive RA, polymyalgia rheumatica. International multicenter study could allow us to confirm the data already present in the literature in the single clinical studies and to evaluate when to effectively supplement vitamin D in patients who do not take corticosteroids.

Extra-Skeletal Effects of Vitamin D

The vitamin D receptor is expressed in multiple cells of the body (other than osteoblasts), including beta cells and cells involved in immune modulation (such as mononuclear cells, and activated T and B lymphocytes), and most organs in the body including the brain, heart, skin, gonads, prostate, breast, and gut. Consequently, the extra-skeletal impact of vitamin D deficiency has been an active area of research. While epidemiological and case-control studies have often suggested a link between vitamin D deficiency and conditions such as type 1 and type 2 diabetes, connective tissue disorders, inflammatory bowel disorders, chronic hepatitis, food allergies, asthma and respiratory infections, and cancer, interventional studies for the most part have failed to confirm a causative link. This review examines available evidence to date for the extra-skeletal effects of vitamin D deficiency, with a focus on randomized controlled trials and meta-analyses.

Could vitamin D deficiency influence left heart ventricular geometry in youngsters with type 1 diabetes mellitus?

BACKGROUND

Experimental and clinical studies have shown the cardio-protective, anti-inflammatory, and anti-atherosclerotic actions of vitamin D.

MATERIAL AND METHODS

We aimed to investigate a possible correlation between vitamin D status and heart geometry using echocardiographic parameters of the left ventricle in youngsters with type 1 diabetes mellitus (T1D). Seventy-eight pediatric patients (aged 13.47 ± 2.86 years) with T1D of more than two years duration and 74 healthy controls (aged 12.04 ± 2.79 years) were enrolled in this case-control study. Anthropometric parameters were recorded, vitamin D and parathormone serum levels were measured, and trans-thoracic echocardiographic study was performed.

RESULTS

Vitamin D deficiency was found in 74 % T1D patients and in 72 % of the controls, while parathormone levels were normal in both groups. T1D patients presented significantly higher values of interventricular septal thickness at diastole (IVSD) compared to controls (0.76 ± 0.16 cm vs 0.71 ± 0.14 cm, p =0.043). All other echocardiographic parameters did not exhibit significant differences between patients and controls. The diastolic function of the left ventricle (LV) was normal in both groups. After sub-grouping, the participants according to the deficiency or not of vitamin D, only patients with T1D and low vitamin D levels had increased values of IVSD compared to controls (0.78 ± 0.17 vs 0.71 ± 0.14, p =0.008). Patients with T1D and normal vitamin D levels presented similar values of IVSD compared to controls (0.71 ± 0.12 vs 0.73 ± 0.15, p =NS).

CONCLUSIONS

Children and adolescents with T1D and normal vitamin D levels do not exhibit changes in LV dimensions or diastolic function, except for increased IVSD, compared to controls. Larger and longitudinal studies are required to confirm and consolidate this finding. HIPPOKRATIA 2019, 23(1): 9-14.

Adolescent type 2 diabetes: Comparing the Pediatric Diabetes Consortium and Germany/Austria/Luxemburg Pediatric Diabetes Prospective registries

OBJECTIVE

To examine and compare the clinical characteristics and treatment of youth with type 2 diabetes (T2D) in two registries: one in Europe and one in the United States.

METHODS

Youth with onset of T2D at 10 to 18 years of age with current age <20 years and an office visit after diabetes duration >1 year were identified in the European (Prospective Diabetes Follow-up, DPV) and the United States (Pediatric Diabetes Consortium, PDC) databases. Demographic, physical and clinical characteristics and treatment at diagnosis as well as physical characteristics, treatment, laboratory data, and diabetes adverse events at most recent visit were analyzed from both registries.

RESULTS

At diagnosis, the majority were female and obese; 70% of DPV vs 34% of PDC youth were diagnosed by targeted diabetes testing. PDC youth were younger, 12 vs 13 years (P < 0.001), had a greater body mass index-SDS, 3.07 vs 2.74 (P < 0.001), a higher hemoglobin A1c (HbA1c), 9.9% vs 7.1% (P < 0.001), were more likely to present in DKA, 7.5% vs 1.3% (P < 0.001) and more likely to be treated with insulin, 62% vs 32% (P < 0.001); insulin treatment difference was not significant when adjusted for HbA1c. At follow-up, DPV youth had shorter diabetes duration, 2.1 vs 3.2 years (P < 0.001), lower HbA1c, 6.5% vs 7.8% (P < 0.001), were less likely to be treated with insulin, 36% vs 56%, (P < 0.001), and were more likely to have dyslipidemia and hypertension than PDC youth. PDC youth had a higher rate of microalbuminuria.

CONCLUSIONS

Both DPV and PDC youth have multiple risks for diabetes complications. Understanding reasons for persistently higher HbA1c in PDC youth requires further study.

Vitamin D levels are associated with metabolic syndrome in adolescents and young adults: The BCAMS study

BACKGROUND AND AIMS

The relationship between vitamin D deficiency and metabolic syndrome (MS) remains controversial with relatively sparse data among youth. Therefore, we attempted to explicate the association of 25-hydroxyvitamin D [25(OH)D] levels with MS in Chinese adolescents and young adults.

METHODS

A cohort of 559 subjects at elevated risk of MS were recruited at 14-28 years of age as a follow-up to the Beijing Child and Adolescent Metabolic Syndrome Study. Subjects underwent clinical assessment including a 2h-oral glucose tolerance test. The concentrations of 25(OH)D, glucose, insulin and lipids were determined. MS was defined using the 2009 harmonized definition.

RESULTS

The prevalence of vitamin D deficiency (< 20 ng/ml) was 78.3%. After adjusting for age, gender and season, 25(OH)D concentrations were negatively correlated with neck circumference, percent body fat, LDL cholesterol, fasting and 2h-glucose levels (all P < 0.05). 25(OH)D levels were significantly lower in participants with obesity, high triglycerides, type 2 diabetes, or MS, compared to their respective counterparts (all P < 0.05). After adjusting for potential confounders (e.g., body mass index), participants in the lowest 25(OH)D tertile were 2.5 times more likely to exhibit MS than were those in the highest tertile (Odds Ratio: 2.48; 95% CI: 1.13-5.45, P < 0.05).

CONCLUSIONS

Vitamin D deficiency was very common in this young Chinese population at risk for MS. Given this association between low vitamin D levels and MS, the role of vitamin D supplementation in Chinese youths needs further examination, particular in those at risk for MS.

Treating vitamin D deficiency in children with type I diabetes could improve their glycaemic control

Background and aims

The relationship between vitamin D deficiency and type I DM is an ongoing area of interest. The study aims to identify the prevalence of vitamin D deficiency in children and adolescents with T1DM and to assess the impact of treatment of vitamin D deficiency on their glycaemic control.

Methods

Retrospective data was collected from 271 children and adolescents with T1DM. The vitamin D deficient (25(OH)D <30 nmol/L) and insufficient (25(OH)D 30–50 nmol/L) patients were treated with 6000 units of cholecalciferol and 400 units of cholecalciferol, once daily for 3 months respectively. HbA1c and 25(OH)D concentrations were measured before and at the end of the vitamin D treatment.

Results

14.8% from the whole cohort (n = 271) were vitamin D deficient and 31% were insufficient. Among the children included in the final analysis (n = 73), the mean age and plasma 25(OH)D concentration (±SD) were 7.7 years (±4.4) and 32.2 nmol/l (±8.2) respectively. The mean 25(OH)D concentration post-treatment was 65.3 nmol/l (±9.3). The mean HbA1c (±SD) before and after cholecalciferol was 73.5 mmol/mol (±14.9) and 65 mmol/mol (±11.2) respectively (p < 0.001). Children with higher pre-treatment HbA1c had greater reduction in HbA1c (p < 0.001) and those with lower 25(OH)D concentration showed higher reduction in HbA1c (p = 0.004) after treatment.

Conclusions

Low 25(OH)D concentrations are fairly prevalent in children and adolescents with T1DM, treatment of which, can potentially improve the glycaemic control.

Epidemiology of Skeletal Health in Type 1 Diabetes

The skeleton is adversely affected by type 1 diabetes (T1D). Patients with T1D of both sexes have an increased risk of fracture that begins in childhood and extends across the entire lifespan. T1D is characterized by mild to modest deficits in bone density, structure, and microarchitecture. Current evidence suggests that the observed bone deficits in T1D are the result of impaired bone formation rather than increased bone resorption. There is emerging data that bone quality is impaired in T1D, which may explain the findings that fracture risk is elevated out of proportion to the degree of bone mineral deficit. In this review, we summarize the current knowledge regarding the epidemiology of skeletal health in T1D. Given the high individual and societal burden of osteoporotic fracture, there is an urgent need to better understand the etiology of T1D-related bone disease so that clinical strategies to prevent fracture can be developed.