Butyrylcholinesterase as a potential biomarker of metabolic imbalances in Afro-descendant populations

BACKGROUND: This study investigated butyrylcholinesterase (BChE) activity and its genetic variants (-116, A, and K) in Afro-Brazilian individuals living in two African-derived communities (quilombos) in southern Brazil. Parameters, including obesity, glucose, and lipid profile, were compared with those of Euro-Brazilian individuals from the same region. The study aimed to characterize population parameters and assess their influence on factors involved in metabolic syndrome, obesity, and type 2 diabetes mellitus (TDM2). METHODS: A total of 198 Afro-Brazilians and 114 Euro-Brazilians participated. BChE activity was measured using the Ellman method, and variants were genotyped by PCR-SSP. Statistical analyses included t-test or Mann-Whitney, ANOVA, chi-square or Fisher's exact test, correlations, and age- and sex-adjusted regression models. RESULTS: The mean BChE activity in the Quilombola population was 3.71 U/mL and was significantly higher in people with TDM2 and/or obesity (p = 0.016), and associated with triglycerides, total cholesterol, overweight, and male sex. A significant interaction between triglycerides and glycated hemoglobin was observed (p = 0.016). BChE activity was higher in Quilombolas than in Euro-Brazilians, regardless of metabolic status, suggesting ethnic influence. BCHE gene variants (A, -116, and K) showed frequencies similar to other populations. Although enzymatic activity varied among haplotypes, differences were not statistically significant. These results highlight the relevance of clinical and ethnic factors in interpreting BChE activity. CONCLUSIONS: This study revealed higher BChE activity and TDM2 prevalence in Afro-Brazilian populations compared to Euro-Brazilians, and these differences correlate with non-genetic factors. The BCHE genetic variants investigated showed no robust associations after correction for multiple testing, suggesting that their effects on metabolic traits may be subtle and context-dependent. This is the first study to quantify BChE activity in Afro-Brazilian Quilombola populations and the second in Black individuals in Brazil, highlighting the importance of considering genetic and ethnic factors in metabolic risk assessment.