Risk factors for multiple long-term conditions—multimorbidity—among adolescents and young adults in Brazil: a gender perspective

Recent studies reveal a rise in multimorbidity or Multiple Long-term Conditions (MLTC) among younger people, driven by unhealthy lifestyles and environmental stressors. This study investigates demographic, socioeconomic, health, and lifestyle risk factors for MLTC among Brazilian youth, with a focus on gender differences. Using a cross-sectional approach and data from the 2019 Brazilian National Health Survey, the study examined MLTC among individuals aged 15–29. MLTC was defined using a universe of 14 self-reported chronic conditions. Adjusted multivariate logistic regression was used to identify predictors, and average marginal effects were used to estimate the risk of multimorbidity. According to a survey of 17,708 young people, the overall MLTC prevalence was 8.02%, higher than that among young women (9.7%). Depression and mental disorders linked to asthma, hypercholesterolemia and hypertension were common. The key predictors included self-perceived health, self-esteem, and sleep disturbances. Regional socioeconomic disparities can mask problems of under- and overdiagnosis of the diseases analysed. Education and physical activity were not significant factors in this study. Rising rates of multimorbidity among young people present significant challenges for healthcare systems and society as a whole. A significant association exists between chronic physical illnesses and mental health disorders in youth with multiple long-term conditions (MLTC), influenced by gender. Conditions like mixed depressive and anxiety disorders, along with physical-mental comorbidities, can lead to psychosocial issues, health risks, and poor quality of life. Understanding MLTC among young people is essential for preventing chronic diseases early in life, particularly in LMICs.