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

Abstract

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.