Associations between perceived stress, psychosocial stressors, and HbA1c levels in healthy young adults from a prospective cohort study

Type 2 diabetes (T2D) is increasingly prevalent globally and in Denmark. T2D diagnosed between 18 and 45 years often runs a more aggressive course with heightened morbidity. Diagnosis occurs at glycated haemoglobin (HbA1c) levels exceeding 48 mmol/mol, while prediabetes (HbA1c 39-47 mmol/mol) also predicts excess mortality and 20-40% progress to T2D within a few years. Stress is proposed to contribute to T2D development through lifestyle adaptations or psycho-endocrine pathways. This study explores whether perceived stress and psychosocial stressors (e.g., poor family functioning, limited social contact, adverse life events) in young adulthood correlate with HbA1c levels among Danish young adults. Data were from the West Jutland Cohort Study and included 355 participants who completed a questionnaire at age 32 or 38 and had HbA1c blood samples taken approximately one year later. Perceived stress and psychosocial stressors were categorised at the 25th and 75th percentiles. The outcome was HbA1c (mmol/mol) at age 33 or 39. Multivariable linear regression models, using inverse probability weights to reduce socioeconomic bias, analysed associations between exposure variables and HbA1c, adjusting for sociodemographic characteristics and physical activity. HbA1c tended to vary modestly with perceived stress and psychosocial stressors, with patterns differing by exposure type and estimates lacking statistical significance. Social contact displayed the most pronounced tendency, with low contact corresponding to a 0.31 mmol/mol higher HbA1c [-0.73; 1.35] compared to high social contact. The observed tendencies between some of the psychosocial stressors and HbA1c levels in young adults may indicate potential negative impacts on metabolic health. However, the small effect sizes and the study's small sample size should be considered when interpreting the findings. Further research is warranted to clarify these potential effects and guide future public health strategies.