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

Association of adiposity, serum vitamin D, and dietary quality with cardiometabolic risk factors in children aged 6-12 years: findings from SEANUTS II Malaysia

Increased cardiometabolic risk among children is increasingly becoming a concern, with evidence indicating that obesity, diet, and serum 25-hydroxyvitamin D (25(OH)D) are associated with cardiometabolic risk. However, such studies among Malaysian children are scarce. Thus, this study explores the associations between adiposity, dietary quality, and 25(OH)D, with cardiometabolic risk factors among Malaysian children aged 4-12 years. Data of 479 children (mean age: 8.2 ± 2.3 years old, 52% females) from the South East Asian Nutrition Surveys (SEANUTS II) Malaysia, were included in this analysis. Adiposity (percentage of body fat) was assessed with bioelectrical impedance technique. Dietary quality was assessed using 24 h dietary recall and calculated as mean adequacy ratio. Vitamin D was assessed based on serum 25-hydroxyvitamin D (25(OH)D). Measurements of cardiometabolic risk factors included waist circumference (WC), mean arterial pressure (MAP), fasting blood glucose (FBG), high-density lipoprotein (HDL), triglyceride, and high-sensitivity C-reactive protein, and cardiometabolic risk cluster score (siMS) was calculated. Overall, higher adiposity was positively associated with all cardiometabolic risk factors (WC, ß = 0.907; 95% CI = 0.865, 0.948; MAP, ß = 0.225; 95% CI = 0.158, 0.292; HDL, ß = -0.011; 95% CI = -0.014, -0.009; Triglyceride, ß = 0.012; 95% CI = 0.009, 0.016; FBG, ß = 0.006; 95% CI = 0.002, 0.011) and siMS score (ß = 0.033; 95% CI = 0.029, 0.037). Serum 25(OH)D was inversely associated with siMS score (ß = -0.002; 95% CI = -0.004, -0.000008) and positively associated with HDL (ß = 0.002; 95% CI = 0.0001, 0.003). Our findings suggest that adiposity is a key determinant of adverse cardiometabolic risk factors in children, while serum 25(OH)D may be associated with overall cardiometabolic health. Interventions to reduce obesity are needed to mitigate the deleterious consequences of cardiometabolic dysregulation in children.

Serum 25-Hydroxyvitamin D Is Associated With Prediabetes, Type 2 Diabetes Mellitus, and Insulin Resistance in Children: A Systematic Review and Dose-Response Meta-analysis of Epidemiologic Studies

CONTEXT

Although several investigations have been conducted on the association between serum vitamin D levels and prediabetes and type 2 diabetes mellitus (T2DM) in children and adolescents, their findings are inconsistent.

OBJECTIVE

We conducted a systematic review and dose-response meta-analysis to summarize this subject.

DATA SOURCES

The electronic databases of ISI Web of Science, Scopus, PubMed, and motor engineering of Google Scholar were comprehensively searched up to May 2023.

DATA EXTRACTION

Epidemiologic studies that investigated the risk of hyperglycemia and insulin resistance in relation to serum 25-hydroxy vitamin D levels in children and adolescents were included.

DATA ANALYSIS

Twenty-two investigations, with a total of 38 622 participants, were systematically reviewed. Meta-analysis of 15 studies (n = 32 720 participants) showed that participants with the highest serum vitamin D levels had 42% lower risk of hyperglycemia, compared with those in the lowest category of serum vitamin D levels (relative risk [RR] = 0.58; 95%CI, 0.48, 0.71). Moreover, pooling 8 studies (n = 10 465 participants) illustrated that highest serum vitamin D level was associated with a 44% lower risk of insulin resistance compared with the lowest serum vitamin D level (RR = 0.56; 95%CI, 0.37, 0.83). Based on linear dose-response analysis, each 10 nmol/L increment in serum 25-hydroxy vitamin D was associated with a 6% decreased risk of hyperglycemia and insulin resistance in children. Furthermore, nonlinear dose-response analysis revealed that increasing serum vitamin D concentration from 40 nmol/L to sufficient values (>50 nmol/L) was associated with a decreasing trend in risk of hyperglycemia and insulin resistance.

CONCLUSION

This meta-analysis revealed inverse associations between serum vitamin D levels and hyperglycemia and insulin resistance in children and adolescents, in a dose-response manner. Increasing serum vitamin D concentration from 40 nmol/L to sufficient values (>50 nmol/L) was associated with a decreasing trend in hyperglycemia and insulin resistance risk. Systematic Review Registration: PROSPERO registration no. CRD42023458155.

Dietary carbohydrate quality index and cardio-metabolic risk factors

Introduction: Improving the quality of diet is known as one of the practical ways to reduce cardio-metabolic risk factors (CMRFs). The carbohydrate quality index (CQI) is a relatively new index to evaluate diet quality. It is calculated based on the ratio of solid carbohydrates to total carbohydrates, dietary fibre intake, glycemic index and the ratio of whole grains to total grains. This systematic review and meta-analysis was designed to investigate the association between dietary CQI and CMRFs. Methods: In this systematic review, some international databases, including Scopus, PubMed, EMBASE, Web of Science, and Google Scholar up to July 2022, were searched according to appropriate keywords. All observational studies with an English full text assessing the association between the dietary CQI and CMRFs were included. Two researchers independently extracted the data and assessed the quality of the articles with the Newcastle-Ottawa Scale. Random/fixed-effect meta-analysis was used to pool standardized mean difference (SMD) as an effect size. Results: 11 studies with a total of 63962 subjects were found to be eligible and included in the qualitative synthesis; only BMI, WC and metabolic syndrome reached the threshold of 3 reports with the same effect size and thus only 5 were included in the meta-analysis. The main finding of the included studies was that there were inverse associations between CQI and CMRFs, mainly obesity, glucose metabolism indices, and blood pressure. In the five studies included in the random effect meta-analysis, the association between CQI and body mass index (SMD: 0.45, 95%CI: -0.12, 1.01), waist circumference (SMD: -0.09, 95%CI: -0.34, 0.15) and metabolic syndrome (SMD: 0.63, 95%CI: -0.01, 1.28) was not statistically significant. Conclusion: Although the qualitative findings support the positive association of CQI with CMRFs, the evidence is insufficient to conclude robust findings. Further observational and interventional studies are needed to clearly elucidate this association.

The association between serum vitamin D levels and abnormal lipid profile in pediatrics: A GRADE-assessed systematic review and dose-response meta-analysis of epidemiologic studies

CONTEXT

Several studies have investigated the relationship between serum vitamin D and dyslipidemia in children and adolescents, but the findings have been contradictory.

OBJECTIVE

The current systematic review and dose-response meta-analysis investigated the serum vitamin D - dyslipidemia relationship in children and adolescents.

DATA SOURCES

ISI Web of Science, Scopus, MEDLINE (PubMed), EMBASE databases, and Google Scholar, were searched up to December 2022.

DATA EXTRACTION

Observational studies that investigated the odds of dyslipidemia in categories of serum vitamin D levels in children were included, and their data were extracted.

DATA ANALYSIS

Pooling of 17 effect sizes from 15 studies (39 342 participants) showed that subjects with higher serum vitamin D had 27% lower odds of hypertriglyceridemia (odds ratio [OR] = 0.73; 95% confidence interval [CI]: 0.60, 0.88). A meta-analysis of 18 effect sizes from 16 studies (39 718 participants) illustrated that highest vs lowest serum vitamin D was related to 22% lower odds of low high-density lipoprotein cholesterol (HDL-c) (OR = 0.78; 95% CI: 0.66, 0.91). Also, a nonlinear association between serum vitamin D and odds of abnormal lipid profile was found: elevating values of 25-hydroxyvitamin D from 35 nmol/L to 55 nmol/L was associated with a decreasing trend in odds of hypertriglyceridemia, hyper low-density lipoprotein cholesterolemia, hypercholesterolemia, and hypo HDL-cholesterolemia. However, no significant linear association was observed. Based on the Grading of Recommendations, Assessment, Development and Evaluations (GRADE), the certainty of all evidence was rated as high.

CONCLUSION

This meta-analysis revealed that the level of 25-hydroxyvitamin D was inversely related to odds of abnormal serum triglycerides and HDL-c in children and adolescents. Increasing serum vitamin D from 35 nmol/L to 55 nmol/L was associated with a decreasing trend in the odds of abnormal serum triglycerides, HDL-c, low-density lipoprotein cholesterol, and total cholesterol in children.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. 42023400787.