Association Between Lumbar Spinal Stenosis and Accelerated Biological Aging Estimated by PhenoAge

<b>Background/Objectives</b>: PhenoAge utilizes biochemical biomarkers to differentiate mortality risk in persons of the same chronological age. However, the details of the relationship between PhenoAge and lumbar spinal stenosis (LSS) remain unclear. We investigated the association between lumbar spinal stenosis (LSS) and biological age quantified by PhenoAge and PhenoAge acceleration (PhenoAgeAccel), comparing surgically treated patients with age- and BMI-matched controls. <b>Methods</b>: This study included 208 LSS patients who underwent surgery. The patients were categorized into four subgroups based on gender and age (≥70 years) at the time of surgery. Demographic data, blood biomarkers, body composition measurements, and Phenotypic age acceleration (PhenoAgeAccel), which was assessed by calculating the residuals from regressing PhenoAge on chronological age were compared among the groups. We also compared control groups matched for age and body mass index (BMI) for each of the four groups using medical examination data. <b>Results</b>: The mean age was 70.2 ± 9.3 years and the mean PhenoAgeAccel was -5.7 ± 6.5 years in the LSS group. PhenoAgeAccel was significantly lower in the control group (-8.5 ± 3.7 years) than in the LSS group, especially in young male (LSS: -2.9 ± 6.7, Control: -7.0 ± 2.8 years), old male (-4.8 ± 4.4, -6.7 ± 4.0 years), and old female (-6.9 ± 5.9, -10.8 ± 3.2 years) subgroups. In the correlation coefficient between PhenoAgeAccel and BMI, there were weak positive correlations (CC: 0.08-0.31) across all subgroups in the control group, whereas there was a weak negative correlation (CC: -0.29) in the old female subgroup in the LSS group. <b>Conclusions</b>: The impact of LSS on PhenoAgeAccel varied by age and gender, and the adverse effect of LSS could be particularly pronounced in elderly women with low BMIs.