Vitamin D status and associated factors in recent-onset type 1 diabetic children in Iran

Proportion of vitamin D deficiency in children/adolescents with type 1 diabetes: a systematic review and meta-analysis

BACKGROUND

The impact of vitamin D on type 1 diabetes has been a controversial topic in public health. Furthermore, significant differences in the proportion of vitamin D have been noted. The purpose of this systematic review was to determine the overall proportion of vitamin D deficiency in children/adolescents with type 1 diabetes (T1D).

METHODS

Based on six electronic databases (PubMed, Web of Science, Embase, Ovid Medline, ProQuest, and Cochrane Library), eligible studies since the databases' inception up to April 2022 were searched. Reference lists were also manually searched to identify additional studies. Overall, studies with statistical information on vitamin D deficiency in children and adolescents with T1D were included, and a random effects model was applied for the meta-analysis. In addition, subgroup and sensitivity analyses were carried out to evaluate heterogeneity, and publication bias was evaluated by using Egger's test.

RESULTS

A total of 45 studies involving 6,995 participants met the inclusion criteria; these included 25 countries covering Africa, Oceania, Europe, North America and Asia. The proportion of vitamin D deficiency in children/adolescents with T1D was 45% (95% confidence interval [CI] 37-54%, I2 = 97.94%). Subgroup analysis further revealed that the publication year, study design, vitamin D classification, season and geographical region significantly contributed to the variation in the reported incidence of vitamin D deficiency.

CONCLUSIONS

The results of the meta-analysis showed that the proportion of vitamin D deficiency among T1D children/adolescents was 45%. In addition, the proportion remains higher, which has important implications for adapting health and social care systems.

Vitamin D status in children and adolescents with type 1 diabetes in a specialized diabetes care centre in Bangladesh

OBJECTIVES

High prevalence of vitamin D deficiency (VDD) in children and adolescents with type 1 diabetes (T1D) was found in several epidemiological studies. The current study aimed to assess the Vitamin D status in children and adolescents with T1D and to examine the influence of the disease characteristics on vitamin D status in a specialized care centre in a tertiary hospital in Bangladesh.

METHODS

Participants were enrolled in the cross-sectional study at the time of a regularly scheduled visit to the CDiC Paediatric Diabetes Center in BIRDEM 2(Bangladesh Institute of Research and Rehabilitation of Diabetes Endocrine and Metabolic Disorders), a tertiary care hospital in Bangladesh. The demographic and clinical data were collected through medical records with a structured questionnaire.

RESULTS

Among sixty study participants, most had inadequate levels of vitamin D: deficiency 31 (51.7%), insufficiency 14 (23.3%) and sufficiency 15 (25.0%). Participants with vitamin D deficiency (VDD) were significantly older compared to the sufficient and insufficient group (p = .029), and were residing in urban areas (p = .036) and from higher socioeconomic status (p = .014). BMI was significantly higher in VDD compared to the sufficient group (p = .040). Although we observed higher median values of daily insulin requirements and HbA1c values in patients with VDD compared to patients with vitamin D insufficiency or vitamin D sufficiency, these differences did not reach statistical significance.

CONCLUSIONS

The present study revealed that the prevalence of vitamin D deficiency and insufficiency among T1 diabetes children was very high. Future studies in large sample are required to assess hypovitaminosis D in youth with T1D and also the possible relating factors of vitamin D deficiency.

Hubungan Paparan Sinar Matahari, Status Gizi, dan Asupan Makan terhadap Kadar Vitamin D Anak dan Remaja Penderita Diabetes Mellitus Tipe 1

Background: Previous research state the correlation between vitamin D deficiency and Type 1 diabetes. The deficiency of Vitamin D is caused by vitamin D intake, sunlight exposure, or nutritional status. Indonesia, as a tropical country, is close to the equator and receives sunlight all year long. Little research has been done on vitamin D levels in children and adolescents with Type 1 Diabetes in Indonesia.Objective: The study aims to determine the relationship among sunlight exposure, nutritional status, food intake, and vitamin D levels in children and adolescents with Type 1 Diabetes.Methods: The study design was cross-sectional with a sample size of 31 children and adolescents aged 5-19 years. Sunlight exposure data were collected using the Sun Exposure Questionnaire form, nutritional status o BMI/age data were using the WHO Anthro, food intake data were using the Semi-Quantitative Food Frequency Questioner, and vitamin D level data were using the ELISA method. Statistical analysis was conducted by using SPSS Version 21 with Pearson and Spearman correlation test.Results: All respondents showed vitamin D deficiency. Most respondents had low sunlight exposure and nutritional status in the normoweight category. The majority of respondents had good energy and protein intake, excess fat, low carbohydrates, and low vitamin D and calcium.Conclusion:There is a positive relationship between sunlight exposure and vitamin D level (p = 0.001, r = 0.627). However, there is no relationship among nutritional status, protein intake, fat, carbohydrates, vitamin D and calcium on the level of vitamin D (p = 0.409; p = 0.240; p = 0.311; p = 0.822; p = 0.231; 0.382).

Prevalence and determinants of vitamin D deficiency in Iranian children and adolescents: the CASPIAN-V study

Purpose

To examine the prevalence and determinants of vitamin D deficiency in Iranian children and adolescents.

Methods

We used data from a national school-based surveillance program conducted among 7-18-year-old children and adolescents living in rural and urban areas in 30 provinces of Iran. Data on student's lifestyle, health behaviors, and health status was obtained through a validated questionnaire. Serum 25-hydroxy vitamin D (25-OH-D) level was measured by chemiluminescent immunoassay. Vitamin D deficiency was defined as serum 25-OH-D concentrations < 30 ng/ml. Determinants of vitamin D deficiency were identified using logistic regression analysis.

Results

Data of 2,596 participants were available for this study. Prevalence of vitamin D deficiency was 71.1 % (95 % Confidence interval (CI): 69.3-72.8 %), without significant difference between boys and girls (72.0 % vs. 70.1 %, respectively, p = 0.29). In the multivariate regression model, in both genders, those who reported having sun exposure for at least 30 min/day and those taking vitamin D supplementation had lower odds for vitamin D deficiency (all p values < 0.05). In boys, obesity increased the odds of vitamin D deficiency (adjusted OR, 95 % CI: 1.57, 1.08-2.27). The association of vitamin D deficiency with other demographic characteristics and food items was not statistically significant.

Conclusions

This large population-based study revealed a high frequency of hypovitaminosis D in Iranian children and adolescents. Sun exposure for at least 30 min/day and taking vitamin D supplementation may reduce the risk of vitamin D deficiency.

High Prevalence of Vitamin D Deficiency among Iranian Population: A Systematic Review and Meta-Analysis

BACKGROUND

The prevention and correction of vitamin D deficiency requires a precise depiction of the current situation and identification of risk factors in each region. The present study attempted to determine these entities using a systematic review and meta-analysis in Iran.

METHODS

Articles published online in Persian and English between 2000 and November 1, 2016, were reviewed. This was carried out using national databases such as SID, IranMedex, Magiran, and IranDoc and international databases such as PubMed, Google Scholar, and Scopus. The heterogeneity index among the studies was determined using the Cochran (Q) and I2 test. Based on the heterogeneity results, the random-effect model was applied to estimate the prevalence of vitamin D deficiency. In addition, meta-regression analysis was used to determine heterogeneity-suspected factors, and the Egger test was applied to identify publication bias.

RESULTS

The meta-analysis of 48 studies identified 18531 individuals with vitamin D deficiency. According to the random-effect model, the prevalence of vitamin D deficiency among male, female, and pregnant women was estimated to be 45.64% (95% CI: 29.63 to 61.65), 61.90% (95% CI: 48.85 to 74.96), and 60.45% (95% CI: 23.73 to 97.16), respectively. The results of the meta-regression analysis indicated that the prevalence of vitamin D deficiency was significantly different in various geographical regions (β=4.4; P=0.023).

CONCLUSION

The results obtained showed a significant prevalence of vitamin D deficiency among the Iranian population, a condition to be addressed by appropriate planning.

Skeletal growth and bone mineral acquisition in type 1 diabetic children; abnormalities of the GH/IGF-1 axis

Type 1 diabetes mellitus (T1DM) is one of the most common chronic diseases diagnosed in childhood. Childhood and adolescent years are also the most important period for growth in height and acquisition of skeletal bone mineral density (BMD). The growth hormone (GH)/insulin like growth factor -1 (IGF-1) axis which regulates growth, is affected by T1DM, with studies showing increased GH and decreased IGF-1 levels in children with T1DM. There is conflicting data as to whether adolescents with TIDM are able to achieve their genetically-determined adult height. Furthermore, data support that adolescents with T1DM have decreased peak BMD, although the pathophysiology of which has not been completely defined. Various mechanisms have been proposed for the decrease in BMD including low osteocalcin levels, reflecting decreased bone formation; increased sclerostin, an inhibitor of bone anabolic pathways; and increased leptin, an adipocytokine which affects bone metabolism via central and peripheral mechanisms. Other factors implicated in the increased bone resorption in T1DM include upregulation of the osteoprotegerin/ receptor-activator of the nuclear factor-κB ligand pathway, elevated parathyroid hormone levels, and activation of other cytokines involved in chronic systemic inflammation. In this review, we summarize the clinical studies that address the alterations in the GH/IGF-I axis, linear growth velocity, and BMD in children and adolescents with T1DM; and we review the possible molecular mechanisms that may contribute to an attenuation of linear growth and to the reduction in the acquisition of peak bone mass in the child and adolescent with T1DM.

Vitamin D status in Egyptian children with type 1 diabetes and the role of vitamin D replacement in glycemic control

BACKGROUND

The association of low serum 25 hydroxy cholecalciferol (25OHD) levels with high glucose level and diminished insulin sensitivity suggests that vitamin D (VD) may modulate insulin metabolism. The aim of the study was to screen for vitamin D deficiency (VDD) in pediatric patients with type 1 diabetes (T1D) and study the effect of VD supplementation on their glycemic control and insulin requirements.

METHODS

A prospective cohort study including 50 patients with T1D. VD level was assessed initially and after 3 months of VD supplementation (in those with VDD). HbA1c and insulin requirements were studied at 0, 3 and 6 months of supplementation.

RESULTS

Fifty patients with T1D were included with mean diabetes duration of 4.11±2.34 years. VD level ranged from 0.2 to 33 ng/mL. VD status correlated significantly with daily insulin dose (p=0.030, r=0.306) and HbA1c (p<0.001, r=0.243). Thirty-five patients (70%) had VDD and were allocated for VD supplementation for 3 months. The mean HbA1c improved significantly after supplementation (p=0.003), followed by a significant deterioration at 6 months with no change in their insulin requirements at 3 or 6 months.

CONCLUSIONS

VD was highly prevalent in Egyptian T1D patients. VD supplementation improved glycemic control at 3 months after therapy with no reduction in insulin requirements.

Vitamin D deficiency in Malaysian adolescents aged 13 years: findings from the Malaysian Health and Adolescents Longitudinal Research Team study (MyHeARTs)

OBJECTIVE

To determine the prevalence of vitamin D deficiency (<37.5 nmol/L) among young adolescents in Malaysia and its association with demographic characteristics, anthropometric measures and physical activity.

DESIGN

This is a cross-sectional study among Form 1 (year 7) students from 15 schools selected using a stratified random sampling design. Information regarding sociodemographic characteristics, clinical data and environmental factors was collected and blood samples were taken for total vitamin D. Descriptive and multivariable logistic regression was performed on the data.

SETTING

National secondary schools in Peninsular Malaysia.

PARTICIPANTS

1361 students (mean age 12.9±0.3 years) (61.4% girls) completed the consent forms and participated in this study. Students with a chronic health condition and/or who could not understand the questionnaires due to lack of literacy were excluded.

MAIN OUTCOME MEASURES

Vitamin D status was determined through measurement of sera 25-hydroxyvitamin D (25(OH)D). Body mass index (BMI) was classified according to International Obesity Task Force (IOTF) criteria. Self-reported physical activity levels were assessed using the validated Malay version of the Physical Activity Questionnaire for Older Children (PAQ-C).

RESULTS

Deficiency in vitamin D was seen in 78.9% of the participants. The deficiency was significantly higher in girls (92.6%, p<0.001), Indian adolescents (88.6%, p<0.001) and urban-living adolescents (88.8%, p<0.001). Females (OR=8.98; 95% CI 6.48 to 12.45), adolescents with wider waist circumference (OR=2.64; 95% CI 1.65 to 4.25) and in urban areas had higher risks (OR=3.57; 95% CI 2.54 to 5.02) of being vitamin D deficient.

CONCLUSIONS

The study shows a high prevalence of vitamin D deficiency among young adolescents. Main risk factors are gender, ethnicity, place of residence and obesity.

A randomized placebo-controlled trial of alphacalcidol on the preservation of beta cell function in children with recent onset type 1 diabetes

BACKGROUND & AIMS

This participant-blinded parallel-group randomized placebo-controlled study demonstrated that alfacalcidol (vitamin D analogue) preserves beta cell function in newly diagnosed type 1 diabetes (T1DM) in children.

METHODS

Subjects from outpatient clinic were randomized to intervention and control groups. Inclusion: (1) age 8-15, (2) T1DM, (3) duration <8 weeks, (4) no chronic diseases, (5) stable diet. Exclusion: (1) vitamin D, calcium supplements or fortified foods, (2) hypercalcemia. Intervention group received alfacalcidol 0.25 μg twice daily, while control group received placebo. Insulin given physician-titrated to blood glucose. Safety monitored by serum calcium and phosphate. Beta cell function assessed at 0, 3, 6 months using fasting C-peptide (FCP) and daily insulin dosage per body weight (DID). Primary outcome measured using multivariate repeated measures GLM-ANOVA, with FCP and DID as primary measures and age, gender, sunlight exposure, 25-hydroxy vitamin D, and HbA1c as covariates.

RESULTS

Of 61 subjects, 7 dropped out. GLM-ANOVA showed that groups were different (p=0.019, Eta-squared=0.087), with no significant covariates. FCP was higher and DID lower in the intervention group, with males having stronger responses to alfacalcidol (p=0.001). No adverse effects were observed.

CONCLUSIONS

The study confirmed that alfacalcidol can safely preserve beta cell function in newly diagnosed T1DM in children, with a stronger effect in males.

CLINICAL TRIAL REG NO

IRCT201205159753N1.