Association of dietary choline and betaine intake with diabetes risk: a prospective cohort study from the China Health and Nutrition Survey

Abstract

This study aimed to investigate the association between dietary choline and betaine intake and the risk of diabetes in Chinese adults. A total of 8595 men and 8561 women who were free from diabetes at baseline were included from the China Health and Nutrition Survey (CHNS) from 1991 to 2015. Dietary intake was assessed using three consecutive individual 24-hour dietary recalls combined with a weighing and measuring household food inventory. Diabetes was determined via self-reported diagnosis, use of diabetes medication, fasting plasma glucose ≥7.0 mmol L⁻¹, or hemoglobin A1c (HbA1c) levels ≥6.5%. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Nonlinear associations were examined using restricted cubic spline models. During a median follow-up duration of 11.1 years, 520 men and 527 women developed diabetes. The adjusted HRs (95% CI) across quintiles were 1.00, 0.81 (0.62, 1.06), 0.69 (0.52, 0.92), 0.71 (0.53, 0.95), 0.97 (0.70, 1.35) in men, and 1.00, 0.80 (0.62, 1.05), 0.76 (0.58, 0.99), 0.89 (0.67, 1.18), 0.97 (0.69, 1.36) in women for total choline intake. RCS analyses further revealed a significant nonlinear association between total choline intake and diabetes risk, with a U-shaped association in men and a J-shaped association in women (all P for nonlinearity <0.001). Significant nonlinear dose–response associations were also observed for water-soluble and lipid-soluble choline intake in men and water-soluble choline intake in women. No significant association was found between dietary betaine intake and diabetes risk. Our findings suggest that moderate choline intake (235–380 mg per day in men and lower than 315 mg per day in women) is associated with a lower risk of diabetes, while excessive intake increases the risk in Chinese adults.