●We first investigated the association of dietary choline and betaine intakes with insulin resistance.
●Dietary choline and betaine intakes were negatively correlated with insulin resistance.
●Associations were more pronounced in females than males.
Dietary betaine supplement could ameliorate insulin resistance (IR) in animals, but no data are available for choline. Reports on humans are rare. We aimed to investigate the association between dietary choline and betaine intakes and IR in humans.
2394 adult subjects from the CODING study were assessed. Dietary choline and betaine intakes were evaluated from the Willett Food Frequency Questionnaire. IR was estimated by homeostatic model assessment (HOMA-IR) and quantitative insulin-sensitivity check index (QUICKI). Partial correlation analysis was used to determine the correlations of dietary choline and betaine intakes with IR adjusted for major confounding factors.
Dietary choline and betaine intakes were inversely correlated with levels of fasting glucose and insulin, HOMA-IR, HOMA-β (r: -0.08 to -0.27 for choline and r: -0.06 to -0.16 for betaine, p<0.05) and positively related to QUICKI (r: 0.16 to 0.25 for choline and r: 0.11 to 0.16 for betaine, p<0.01) in both genders after controlling age, total calorie intake and physical activity level. The significant associations disappeared in males after percent trunk fat was added as a confounding factor. Furthermore, subjects with the highest tertile of dietary choline and betaine intakes had the lowest IR severity. Vice versa, dietary choline and betaine intakes were the lowest in the high IR group, intermediate in the medium group and the highest in the low IR group.
This study demonstrated that higher dietary choline and betaine intakes are associated with lower IR in the general human population.
Xiang Gao, Yongbo Wang, Guang Sun