Abstract
BACKGROUND: The possible joint association of vitamin D and obesity in regard to clinical biomarker-based biological aging process has not been well studied. We investigated the independent and combined associations of serum 25-hydroxyvitamin D [25(OH)D] concentrations and body mass index (BMI) with phenotypic age (PhenoAge) and Klemera-Doubal method Biological Age (KDM-BA) acceleration.</p>
METHODS: This study was conducted using data from participants in the UK Biobank baseline survey. Restricted cubic splines and multivariable logistic regression analyses were used to investigate the associations of serum 25(OH)D concentrations and BMI with PhenoAge and KDM-BA acceleration. Mediation analyses were conducted to assess whether biological age acceleration potentially mediated the association between 25(OH)D or BMI and all-cause mortality.</p>
RESULTS: In Analysis 1 (n = 389 217) for PhenoAge, and Analysis 2 for KDM-BA (n = 329 561), participants whose serum 25(OH)D concentration ≥50.0 nmol/L or with normal weight (BMI <25 kg/m2) had the lowest odds of biological age acceleration. Those with both 25(OH)D <25.0 nmol/L and BMI ≥30.0 kg/m2 had the highest odds of PhenoAge acceleration ([OR [95% CI], 2.387 [2.303, 2.474]) and KDM-BA acceleration [OR (95% CI), 4.096 (3.926, 4.274)]. The mediation analysis revealed that PhenoAge acceleration mediated 11.4% and 47.1% of the associations of 25(OH)D and BMI with all-cause mortality; while KDM-BA acceleration accounted for 7.41% and 55.2%.</p>
CONCLUSIONS: Serum 25(OH)D concentrations and BMI were significantly associated with the acceleration of biological aging. Combining vitamin D deficiency and obesity demonstrated enhanced synergistic association on the biological aging process, highlighting the importance of vitamin D and BMI in promoting healthy aging.</p>