Trajectories of Inflammation in Youth and Risk of Mental and Cardiometabolic Disorders in Adulthood.

Key Points: Question: Are differing trajectories of low-grade inflammation throughout childhood and adolescence associated with an increased risk of developing certain mental and related cardiometabolic health conditions in early adulthood? Findings: This longitudinal cohort study found that having persistently raised levels of inflammation as measured by C-reactive protein throughout childhood and adolescence, peaking at age 9 years, was associated with an increased risk of developing psychosis disorder, severe depression, and higher levels of insulin resistance. Meaning: Increased inflammation in childhood may be an important predisposing risk factor to the development of both mental and cardiometabolic disorders in early adulthood. Importance: Research suggests that low-grade, nonresolving inflammation may predate adult mental and physical illness. However, evidence to date is largely cross-sectional or focuses on single disorder outcomes. Objectives: To examine trajectories of inflammation as measured by C-reactive protein (CRP) levels in a large sample of children and adolescents, and to explore associations between different identified trajectories and mental and related cardiometabolic health outcomes in early adulthood. Design, Setting, and Participants: In a longitudinal cohort study using data from the large UK-based Avon Longitudinal Study of Parents and Children (ALSPAC), latent class growth analysis (LCGA) was used to explore different trajectories of inflammation, with logistic regression exploring association with mental and physical health outcomes. Participants with measurable CRP data and associated mental and cardiometabolic health outcomes recorded were included in the analysis. Data analysis was performed from May 1, 2023, to March 30, 2024. Exposures: Inflammation was assessed via CRP levels at ages 9, 15, and 17 years. LCGA was used to identify different trajectories of inflammation. Main Outcomes and Measures: Outcomes assessed at age 24 years included psychotic disorders, depressive disorders, anxiety disorders, hypomania, and, as a measure of insulin resistance, Homeostasis Model Assessment (HOMA2) score. Results: A total of 6556 participants (3303 [50.4%] female) were included. Three classes of inflammation were identified: persistently low CRP levels (reference class, n = 6109); persistently raised CRP levels, peaking at age 9 years (early peak, n = 197); and persistently raised CRP levels, peaking at age 17 years (late peak, n = 250). Participants in the early peak group were associated with a higher risk of psychotic disorder (odds ratio [OR], 4.60; 95% CI, 1.81-11.70; P =.008), a higher risk of severe depression (OR, 4.37; 95% CI, 1.64-11.63; P =.02), and higher HOMA2 scores (β = 0.05; 95% CI, 0.01-0.62, P =.04) compared with participants with persistently low CRP. The late peak group was not associated with any outcomes at age 24 years. Conclusions and Relevance: Low-grade systemic inflammation peaking in midchildhood was associated with specific mental and cardiometabolic disorders in young adulthood. These findings suggest that low-grade persistent inflammation in early life may be an important shared common factor for mental-physical comorbidity and so could be relevant to future efforts of patient stratification and risk profiling. This longitudinal cohort study using data from the Avon Longitudinal Study of Parents and Children (ALSPAC) examines trajectories of inflammation in childhood and their associations with mental and related cardiometabolic health outcomes in early adulthood. [ABSTRACT FROM AUTHOR]