[Association between dietary choline intake trajectories and cognitive function in middle-aged and older population]

Objective: To identify the trajectories of dietary choline intake in middle-aged and older population, and to analyze its longitudinal association with cognitive function. Methods: Subjects aged 55 to 79 years with at least two rounds of completed population economics, lifestyle, disease history, cognitive function, dietary assessments and physical measurements in 1997-2018 and those with at least three rounds of dietary measures in 1991-2015 were selected from the China Health and Nutrition Survey. Dietary survey was conducted using three consecutive 24-hour dietary recalls combined with a weighing inventory at the household level. Cognitive assessment was performed using part of the Telephone Interview for Cognitive Status Scale. Group-based univariate trajectory modeling was used to identify trajectory of choline intake, and three-level linear mixed-effects models or three-level logistic mixed-effects models was employed to analyze the relationship between trajectory groups and cognitive function. Subgroup analyses were conducted by gender and age at baseline. Results: Four trajectories of dietary choline intake were identified in the whole population, named as low-intake-stable group (61.0%), medium-intake-stable group (23.9%), medium-intake-slowly-declined group (11.2%), and high-intake-stable group (3.9%). Three trajectories were identified for each subgroup. Low-intake-stable group accounted for more than 60% in total population as well as each subgroup, especially in women and 55-59 years group. After adjusting for covariates, global cognitive scores were 0.54 (95%CI: 0.26-0.82), 0.77 (95%CI: 0.36-1.18), and 0.85 (95%CI: 0.21-1.48) points higher in medium-intake-stable, medium-intake- slowly-declined and high-intake-stable groups in the whole population, respectively, compared with the low-intake-stable group. The likelihoods of cognitive decline were 18.4% (OR=0.816,95%CI: 0.709-0.939), 17.6% (OR=0.824, 95%CI: 0.680-0.998), 24.4% (OR=0.756, 95%CI: 0.589-0.970) and 22.4% (OR=0.776,95%CI: 0.623-0.968) lower in medium-intake-stable group of dietary choline in the whole population, medium-intake-stable group in males, medium-intake-slightly-increased group in females and medium-intake-slowly-increased group in 55-59 years at baseline than in low-intake-stable group, respectively. Conclusions: Dietary choline intake is generally lower in the Chinese population aged 55-79 years. Long-term lower choline intake has a negative impact on cognitive function in middle-aged and older adults and may increase the risk of cognitive decline. The increment in the consumption of choline-enriched foods should be recommended.