The Association Between Dietary Inflammatory Index with Metabolic Syndrome and Subclinical Atherosclerosis in Children and Adolescents: A Systematic Review

Abstract

Context: Metabolic syndrome (MetS) and increased carotid intima-media thickness (CIMT) in children and adolescents are critical early warning signs for the development of non-communicable disorders in adulthood. Identifying modifiable risk factors such as the Dietary Inflammatory Index (DII) is therefore essential for implementing early public health interventions to prevent irreversible long-term health consequences. Objectives: This systematic review aimed to evaluate the association of DII with MetS and CIMT in children and adolescents. Data Sources: Using three literature databases (PubMed, Web of Science, and Scopus), we searched for studies published between 1 January 2000 and 1 August 2024, which assessed the association of DII with MetS or CIMT among children and adolescents. Study Selection: Two reviewers screened and assessed the quality of studies using the Newcastle-Ottawa Scale. Data Extraction: Given the heterogeneity of study designs, a narrative synthesis approach was employed (PROSPERO: CRD420250643107). Results: Out of 23,393 records identified, two prospective cohorts and five cross-sectional studies met our inclusion criteria, including four and three studies focused on MetS and CIMT as the outcome, respectively. The included studies investigated a combined population of over 13,000 participants, comprising both sexes, aged 6 to 19 years. Two studies, one cross-sectional (odds ratio: 1.20; 95% confidence interval: 1.01, 1.43) and one prospective (β: 0.12; 0.003, 0.22), showed a harmful association between DII and MetS, while two other studies did not find any statistically significant association. Regarding the association between DII and CIMT, two studies noted null associations, while another study observed a positive association with high CIMT [odds ratio = 2.46 (1.15, 5.24)]. Conclusions: In light of the inconsistent associations between the DII with MetS or CIMT reported in the literature, the suggestive evidence of harm from a small number of studies highlights a critical gap.