Higher serum concentrations of betaine rather than choline is associated with better profiles of DXA-derived body fat and fat distribution in Chinese adults

OBJECTIVE: Animal studies have suggested that betaine, but not choline, may improve body composition, but little evidence is available in humans. We examined the association of serum concentrations of choline and betaine with body composition and fat distribution in adults. METHODS: This community-based study recruited 1996 adults (women/men: 1380/616) aged 40-75 years in urban Guangzhou, China. General information and anthropometric measurements were taken, and serum choline and betaine levels were assessed by high-performance liquid chromatography-tandem mass spectrometry between July 2008 and June 2010. After 3.2 years, 1623 of the 1996 participants were measured for fat mass (FM and %FM) over the total body (TB), trunk, limbs, android (A) and gynoid (G) regions. The %FM ratios of the A/G regions and the trunk and limbs were determined by dual energy X-ray absorptiometry. RESULTS: Univariate analyses showed that higher serum betaine levels were significantly associated with lower values of adiposity indices (all P-trends < 0.05), except in the case of the %FM at the gynoid area. After adjusting for potential covariates, similar associations were observed. The mean percentage differences between quartiles 4 and 1 of the serum betaine levels were -4.9% (weight), -4.7% (body mass index, BMI), -2.5% (waist circumference), -7.9% (TB FM) and -3.4% (TB %FM). The mean differences in the FM and %FM were much more pronounced at the trunk (-10.0 and -4.5%) or android areas (-10.7 and -4.7%) than those at the limbs (-0.8 and -2.3%) or gynoid areas (-0.6 and -1.4%). Such favorable associations were stronger in men than in women. No significant associations between serum choline and the adiposity indices were observed, except in the cases of body weight and BMI. CONCLUSIONS: Greater circulating betaine, but not choline, was dose-dependently associated with better body composition and fat distribution due to a lower FM in the trunk regions in this population.