Association Between Skin Autofluorescence and White Blood Cell Counts in Older Adults

Advanced glycation end products (AGEs) accumulate in the body with increasing age. However, their excessive accumulation may lead to various inflammatory and chronic diseases. While it is common for older adults to experience various comorbidities, there is a scarcity of published literature documenting the specific impact of ageing and comorbidities on AGEs in this population. The present study aimed to retrospectively evaluate the correlation among AGEs in the skin, calendar age, and comorbidities in older adults.

Accumulated AGEs in the skin were assessed by non-invasive measurement of skin autofluorescence (SAF) inside the forearm. This retrospective study included individuals who underwent SAF measurements at Shujitsu University Community Pharmacy with or without a prescription from October 2019 to October 2021. Subsequently, the associations between SAF, calendar age, comorbidities, and blood test parameters were investigated.

SAF showed a positive correlation with calendar age for all enrolled participants; the correlation weakened for participants aged ≥50 years and plateaued for those aged ≥60 years. Furthermore, we observed a significant increase in SAF among all participants with comorbidities compared to those without comorbidities. By contrast, among participants aged ≥50 years, SAF did not show a significant association with comorbidities. However, SAF was significantly positively correlated with white blood cell (WBC) counts in these aged populations.

The non-invasive assessment of SAF holds promise in evaluating changes in the physical condition associated with WBC counts among older adults.