U-shaped association between dietary zinc intake and new-onset diabetes: A nationwide cohort study in China.

Abstract

AIMS\nWe aimed to investigate the relationship of dietary zinc intake with new-onset diabetes among Chinese adults.\n\n\nMATERIALS AND METHODS\n16,257 participants who were free of diabetes at baseline from the China Health and Nutrition Survey (CHNS) were included. Dietary intake was measured by 3 consecutive 24-hour dietary recalls combined with a household food inventory. Participants with self-reported physician-diagnosed diabetes, or fasting glucose ≥7.0 mmol/L or glycated hemoglobin ≥6.5% during the follow-up were defined as having new-onset diabetes.\n\n\nRESULTS\nA total of 1,097 participants developed new-onset diabetes during a median follow-up duration of 9.0 years. Overall, the association between dietary zinc intake and new-onset diabetes followed a U-shape (P for nonlinearity <0.001). The risk of new-onset diabetes was significantly lower in participants with zinc intake <9.1\xa0mg/day (per mg/day: HR, 0.73; 95% CI, 0.60-0.88), and higher in those with zinc intake ≥9.1\xa0mg/day (per mg/day: HR, 1.10; 95%CI, 1.07-1.13). Consistently, when dietary zinc intake was assessed as deciles, compared with those in deciles 2-8 (8.9 -<12.2mg/day), the risk of new-onset diabetes was higher for decile 1 (<8.9mg/day: HR,1.29; 95%CI, 1.04-1.62), and deciles 9-10 (≥12.2mg/day: HR,1.62; 95%CI, 1.38-1.90). Similar U-shaped relations were found for plant-derived or animal-derived zinc intake with new-onset diabetes (all P for nonlinearity <0.001).\n\n\nCONCLUSIONS\nThere was a U-shaped association between dietary zinc intake and new-onset diabetes in general Chinese adults, with an inflection point at about 9.1\xa0mg/day.