<scp>DXA</scp> ‐Measured Visceral Adipose Tissue and Accelerated Biological Aging in Middle‐Aged Adults

OBJECTIVE: Obesity, particularly excess visceral adipose tissue (VAT), may accelerate biological aging; however, few studies have examined this in middle-aged adults. We investigated associations between dual-energy X-ray absorptiometry (DXA)-derived VAT and two biomarkers of biological aging-phenotypic age acceleration (PhenoAgeAccel) and leukocyte telomere length (LTL)-in 4799 participants (2614 females, aged 45-69 years) from the Busselton Healthy Ageing Study. METHODS: Whole-body DXA (GE Lunar) quantified VAT mass. Phenotypic age was estimated from chronological age and nine biomarkers. In a subsample of 1221 participants, LTL was measured as the telomeric DNA to single-copy gene (T/S) ratio. Sex-stratified linear regressions assessed associations, adjusting for chronological age and lifestyle factors. RESULTS: Mean ± SD VAT mass was 1677 ± 873 g in males and 882 ± 598 g in females. Higher VAT was associated with greater PhenoAgeAccel in both sexes; each 1-SD increase in VAT corresponds to 1.397 (95% CI 1.197, 1.596) and 1.919 (1.738, 2.099) years higher PhenoAgeAccel in males and females, respectively. In females only, higher VAT was associated with shorter LTL (-0.041 [-0.069, -0.013] per 1 SD). Associations mostly remained significant after adjustment for anthropometric and other DXA-derived adiposity measures. CONCLUSIONS: VAT may represent a specific marker of accelerated biological aging, independent of lifestyle and adiposity measures.