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Background: Socially disadvantaged populations face an increased risk of accelerated biological ageing. Advanced glycation endproducts (AGEs) are an established biomarker of ageing. Lifestyle factors have also been linked to ageing. Research directly exploring the link between socioeconomic status (SES) and biological age using AGEs-accumulation as a biomarker of ageing has not yet been published.

Aim/scientific question: We aimed to analyze the associations of education, income, and occupational class with AGEs-accumulation, stratified by sex, and explored if lifestyle factors mediate these relationships.

Material & Methods: Cross-sectional data from the German National Cohort (NAKO) was used. AGEs levels were measured using SES variables as defined as independent variables. Smoking, alcohol consumption and BMI were considered potential lifestyle mediators.

Multivariable regressions were used to examine SES and AGEs-accumulation, and cross-sectional mediation analysis quantified the possible contribution of lifestyle factors.

Results: Our findings indicate an inverse relationship between accelerated AGEs-accumulation and educational level in both sexes and sex differences in AGE-accumulation by occupation. Men also reported higher numbers of behavioral AGEs-accumulating behaviors.

Among the examined mediators, smoking had the strongest association with AGEs-accumulation, while hazardous alcohol consumption and BMI played only minor roles in both sexes.

Overall, educational level had the largest direct and mediated association with AGEs-accumulation, with occupational class also contributing substantially. Income did not show direct or mediated associations.

Discussion: This study is the first to examine AGEs and SES with regard to mediating lifestyle factors and sex-specific outcomes. Although the cross-sectional design limits causal interpretation, our findings from this large analysis emphasize the outstanding role of smoking as a primary factor of AGEs-accumulation. Hazardous alcohol and high BMI, which are other well-known risk factors for age-related diseases, have shown contrastingly small mediated effects on biological ageing, measured through AGEs-levels.

Take Home Message: Accelerated biological ageing, measured by AGEs-accumulation, is linked to educational level as well as occupational class, but only weakly with income. Smoking emerged as the primary lifestyle mediator of these associations. Sex differences were observed in the association between the main mediator and its contribution to direct effects on AGEs-accumulation.

Competing interests: None