Chinese Healthy Eating Index (CHEI) and risk of diabetes in Chinese adults: a prospective cohort study

Purpose The Chinese Healthy Eating Index (CHEI) is a valid instrument to assess the diet quality of the Chinese population, but evidence regarding the relationship between CHEI and the risk of diabetes remains limited. We aimed to investigate the prospective association of CHEI with diabetes among Chinese adults. Methods 1563 adults free of diabetes at baseline and with at least two survey data from 1997 to 2018 were included. Dietary information was collected by three consecutive 24-h recalls combined with household food inventory, and long-term diet quality was evaluated by the CHEI. Diabetes was defined as self-reported physician-diagnosed diabetes and/or fasting blood glucose ≥ 7.0 mmol/L, and/or HbA1c ≥ 6.5%. Cox proportional hazard models and restricted cubic spline analysis were used to estimate the associations between CHEI and diabetes. Results During a median follow-up of 12.0 years, 192 (10.3%) participants developed new-onset diabetes. Generally, a five-point higher CHEI score was significantly associated with a 17% lower risk of diabetes (HR, 0.83; 95%CI 0.71–0.97). In stratified analysis, inverse associations between CHEI and diabetes were more vigorous in females (HR, 0.68; 95%CI 0.54–0.85) than in males ( P for interactio n = 0.01). In addition, there was an L-shaped association between CHEI and diabetes risk in the whole population ( P for non-linearity = 0.026), while no significant non-linear association was observed in females or males, respectively. Conclusion Our results suggested that a long-term higher-quality diet evaluated by CHEI was significantly associated with lower risks of diabetes, and the favorable associations were more pronounced among females.