(P32-02-26) Diet Quality and Skin Carotenoid Status in Parkinson’s Disease: A Cross-Sectional Analysis

Objectives: Parkinson’s disease (PD) involves the progressive loss of dopamine-producing neurons. Carotenoids, antioxidants rich in fruits and vegetables commonly associated with higher diet quality, may be protective of factors that influence neurodegeneration in PD. The objective of the study is to assess the association between diet quality and skin carotenoid content (SCC) in patients with PD.

Methods: A total of 65 individuals with PD were enrolled in the study. After excluding participants with implausible energy intake (Female: < 500 and >3500 kcal/day; Male: < 800 and >4000 kcal/day), 63 participants were included in the final analysis. Participant dietary intake was assessed using the Diet History Questionnaire (DHQ-III). SCC of the right index finger was measured non-invasively using the Veggie Meter (Longevity Link, Utah, USA). Descriptive statistics and linear regression analyses were performed using R (R Foundation, Vienna, Austria) to evaluate the association between diet quality (Healthy Eating Index 2020 [HEI]) and SCC. The adjusted model included age, sex, and BMI as covariates. We performed mediation analyses, adjusted for age and sex, to investigate the effect of BMI as a mediator of the relationship between HEI and SCC.

Results: Participants were 57.1% male and 42.9% female with mean age of 66.5 ± 7.1 years and BMI of 26.9 ± 3.9 kg/m². The mean HEI and SSC scores were 69.3 ± 9.5 and 283.9 ± 95.4, respectively. In the unadjusted model, higher HEI scores were associated with higher SCC (β=2.8, p=0.02). In the adjusted model, HEI was no longer significantly associated with SCC (p=0.26), while higher BMI was associated with lower SCC (β= -10.4, p=0.001). Because BMI was such a strong predictor of SCC, we formally tested its mediation of the relationship between HEI and SCC. BMI significantly mediated the relationship between HEI and SCC (ACME: p=0.002), whereas the direct effect was not significant (ADE: p=0.21), suggesting this relationship may operate primarily through BMI, accounting for ~50.2% of the total effect as a mediator (Total Effect: p< 0.05).

Conclusions: Our interim pilot results suggest that diet quality is influential in SCC in PD, potentially mediated by BMI. Future research is needed to investigate whether BMI generally mediates the relationship between diet quality and SCC or whether it is specific to PD.

Funding Sources: Not applicable