Accelerated biological aging, mediating amino acids, and risk of incident type 2 diabetes: a prospective cohort study.

Purpose: Aging plays an important role in type 2 diabetes mellitus (T2DM). But the association between accelerated biological age and T2DM, and the mechanisms underlying this association remains unclear. Thus, this study aimed to examine the associations of biological aging with T2DM, and explore the potential mediation effect of amino acids.

Methods: This prospective cohort study included 95,773 participants in the UK Biobank who were free of diabetes at baseline. Biological age was measured from clinical traits using PhenoAgeAccel. Cox proportional hazard models were used to estimate the hazard ritios (HRs) and 95% confidence intervals (CIs), and mediation analysis was used to explore the mediation effect of amino acids.

Results: During a median follow-up of 14.02 years, 6,347 incident T2DM cases were recorded. After multivariable adjustment for sociodemographic characteristics, lifestyle factors, and other risk factors of T2DM, participants with older biological age were at increased risk of incident T2DM (30% increase per standard deviation of PhenoAgeAccel, 95% CI: 28.0-33.0%). Additionally, higher branched chain amino acids (BCAAs) including isoleucine and leucine, aromatic amino acids (AAAs) including phenylalanine and tyrosine, were associated with increased PhenoAgeAccel and risk of incident T2DM; while glutamine and glycine were inversely associated. Alanine, glutamine, glycine, phenylalanine, tyrosine, isoleucine, leucine, and total concentration of branched-chain amnio acids could partially explain the associations between PhenoAgeAccel and T2DM.

Conclusion: Accelerated biological aging was associated with increased risk of incident T2DM independent of chronological age and may be a risk factor of T2DM, partially mediated by several amino acids.