Associations of plasma betaine, plasma choline, choline intake, and MTHFR polymorphism (rs1801133) with anthropometric parameters of healthy adults are sex-dependent

Background Choline and its metabolites apppear to have relationships with body mass index (BMI), body fat, and body weight, but the research results have proved inconsistent. We thus investigated the associations of plasma levels of trimethylamine N-oxide (TMAO), choline, and betaine with anthropometric measurements, including modulatory effects of genetics and diet. Methods The study was performed on a group of 421 adults, aged 20-40 years, who had been recruited in Poland. Plasma concentrations of choline, betaine, and TMAO were determined using reverse-phase ultra-high-performance liquid chromatography electrospray ionisation mass spectrometry. The following polymorphisms were genotyped using TaqMan probes: rs180113 (MTHFR), rs70991108 (DHFR), rs2236225 (MTHFD1), and rs7946 and rs12325817 (PEMT). We employed multivariate linear regression to examine the associations between anthropometric measurements, one-carbon metabolism metabolites, and genotypes. Results Higher plasma choline was associated with higher BMI (beta = 0.17; p < 0.01), body weight (beta = 0.11; p < 0.05), body fat mass (FM) (beta = 0.10; p < 0.05), and waist circumference (WC) (beta = 0.14; p < 0.01), whereas higher choline intake was associated with lower body FM (beta = -0.14; p < 0.01) and lower WC (beta = -0.12; p < 0.01). After stratification by sex, plasma betaine was found to be associated with lower BMI (beta = -0.20; p < 0.05) and body weight (beta = -0.16; p < 0.05) in men only, whereas choline intake was associated with lower body FM (beta = -0.19; p < 0.05) and waist-to-hip ratio (WHR) (beta = -0.19; p < 0.05) and MTHFR CC genotype was associated with WHR (beta = 0.15; p < 0.05) in women only. Conclusions Higher plasma betaine and higher dietary choline are associated with lower FM and body weight, whereas higher plasma choline is positively associated with body weight status and adiposity. Moreover, these associations appear to be sex-specific.