Low socioeconomic status, insulin resistance, asthma, and depression: A syndemic framework in Brazilian adolescents

BACKGROUND: Adolescence is a critical developmental stage during which environmental, metabolic, and psychosocial factors co-occur and may interact, influencing health and creating a syndemic context that remains insufficiently explored. OBJECTIVE: We analyzed a syndemic model, considering socioeconomic determinants and metabolic risk associated with asthma and depression in adolescents. METHODS: This population-based study (n = 2515) utilized data from the RPS Brazilian Consortium Cohorts at follow-up of 18-19 years in São Luís, Brazil. A theoretical model analyzed the association among socioeconomic determinants, metabolic risk, asthma, and depression using Structural Equation Modeling (SEM). Low Socioeconomic Status was a distal determinant. The metabolic risk included the TG/HDL ratio, as an insulin resistance marker, as well as obesity. Asthma was a latent variable based on wheezing, asthma history, medical diagnosis, and frequency of wheezing. Depression was diagnosed based on major and recurrent episodes using the M.I.N.I. RESULTS: Low socioeconomic status was associated with higher insulin resistance precursor (TG/HDL ratio) (standardized coefficient, SC = 0.064; p = .027) and with higher levels of depression (SC = 0.084; p = .001). Higher insulin resistance precursor was associated with asthma (SC = 0.069; p = .042). Asthma was associated with depression (SC = 0.078; p < .001). Lower insulin resistance precursor levels were observed in girls (SC = -0.254; p < .001); meanwhile, obesity (SC = 0.124; p < .001) and depression (SC = 0.165; p < .001) had higher values for them. CONCLUSION: Our findings underscore interconnected issues of low socioeconomic status, metabolic risk, asthma, and depression in adolescents. Recognizing the syndemic framework can lead to more effective health policies to prevent long-term physical and mental health consequences.