(P08-017-25) Feasibility and Acceptability of the Carbon Isotope Ratio From Blood, Breath, Hair, and Nails as a Biomarker of Added Sugar Among Racially and Ethnically Diverse Adolescents

Objectives: Objective measures to capture dietary intake are needed, especially for youth who are susceptible to misreporting and for nutrients of concern like added sugar (AS). The carbon isotope ratio (CIR) is a promising biomarker for AS and can be sampled from a variety of tissues. Feasibility and acceptability of obtaining sample types from adolescents, and the correlation of CIR across sample types, remain understudied.

Methods: Adolescents 12-16 years provided non-fasting CIR samples from blood, breath, hair, and nails. Participants completed pre-post surveys assessing perceived stress/anxiety, comfort, and willingness/preferences for providing the samples. Descriptive values for CIR were calculated and pairwise comparisons examined associations across sample types.

Results: Data were collected from 40 adolescents (14.5(1.5) years, 60% female, 65% non-Hispanic Black/African American, 17.5% Hispanic, 12.5% non-Hispanic White, and 5% other race/ethnicity). All participants (100%) completed breath samples, 97.5% completed blood and nail samples, and 85% completed hair samples. Among those who did not provide hair samples (n=3 males, n=3 females), primary reasons included discomfort and hair style. Participants reported the highest levels of pre-sampling stress/anxiety prior to blood samples (25.6%), compared to hair (13.9%), nails (10.3%), and breath (7.5%). Post-test surveys revealed higher comfort providing breath (92.5%) and nails (92.3%) compared to blood (83.7%) and hair (85.3%). Mean CIR varied across sample types (Breath: -21.5(1.3)‰, Blood: -19.6(0.5)‰, Nail: -18.2(0.6)‰, Hair: -17.8(0.6)‰). Blood CIR was correlated with hair CIR (r=0.7, p≤0.001) and nail CIR (r=0.6, p≤0.001), but not breath CIR (r=0.3). Breath CIR was only correlated with nail CIR (0.4, p=0.03).

Conclusions: Breath was the most feasible and acceptable CIR sample type among adolescents, followed by nails, while hair and blood were less feasible and acceptable. Mean CIR varied across sample types indicating samples might represent varying periods of intake (e.g., breath might reflect shorter-term intake, while hair, blood and nails represent time frames aligned with tissue turnover rates). Future studies are needed to refine sampling approaches to capture AS intake in youth.

Funding Sources: K01HL153783, National Heart, Lung, and Blood Institute (NHLBI)