Association between percutaneous absorption of benzophenone-3 and N, N-diethyl-m-toluamide among the general adult population.

ABSTRACT

BACKGROUND: Multiple studies have confirmed the mutual enhancement of percutaneous permeation of benzophenone-3 (BP-3) and N,N-diethyl-m-toluamide (DEET), which are effective ingredients in sunscreen products and insect repellents, respectively. However, the association between percutaneous absorption of BP-3 and DEET in a large general adult population remains to be elucidated. METHODS: This cross-sectional study included US adults who had available data on urinary BP-3 and two DEET metabolites, 3-(diethylcarbamoyl) benzoic acid (DCBA) and 3-(ethylcarbamoyl) benzoic acid (ECBA), from the National Health and Nutrition Examination Survey (NHANES) conducted in 2015-2016. We conducted three weighted multivariable linear regression models to investigate the potential correlation between percutaneous absorption of BP-3 and DEET, along with trend tests, smooth curve fitting, and subgroup analysis to assess the robustness of the findings. RESULTS: Weighted multivariable linear logistic regression revealed a positive correlation between log10 BP-3 and log10 DCBA (ß = 0.1678, 95 % CI 0.0970 to 0.2386) as well as log10 ECBA (ß = 0.1416, 95 % CI 0.0707 to 0.2125), after adjusting for all covariates. After converting log10 BP-3 from a continuous variable to a categorical variable (quartiles), the trend tests showed that the results were stable (all P for trend < 0.05). Smoothed curve fitting demonstrated a linear positive correlation between log10 BP-3 and both log10 DCBA and log10 ECBA. In subgroup analyses, the positive correlation between BP-3 and DEET metabolites was more pronounced in participants who were male, middle-aged, non-Hispanic white, had a moderate PIR level and reported always or most of the time using sunscreen. CONCLUSIONS: Our findings revealed a statistically significant linear and positive correlation between the percutaneous absorption of BP-3 and DEET in the general adult population.