Association Between Dietary Salt and Plasma Glucose, Insulin and Hemoglobin A_1c Levels Among Type 2 Diabetes Patients in Eastern China

Purpose: Type 2 diabetes (T2D) is one of the major public health concerns in China. Studies on the association between dietary salt intake and the glycemic response of T2D are lacking in China. The aim was to investigate the association between the levels of dietary salt intake and the plasma glucose, insulin and hemoglobin A_1c (HbA_1c) levels in T2D patients. Methods: Patients with T2D, who accepted management and treatment by the National Standardized Metabolic Disease Management Center at Ningbo First Hospital from March 2018 to January 2020, were included in this study. Dietary salt intake was assessed through a standardized food frequency questionnaire. Anthropometry, blood pressure and biomarkers were measured by well-trained endocrinology nurses. Generalized linear models (GLMs) were used to examine the associations. Results: A total of 1145 eligible T2D patients with a mean age of 51.4 years were included in the study. Fasting plasma glucose (FPG), 2-hour postprandial plasma glucose and 2-hour postprandial insulin were significantly increased across dietary salt categories. The GLMs further showed that dietary salt intake >8 g/day was positively associated with FPG and HbA_1c. Conclusion: Higher daily salt intake was found to be associated with FPG and HbA_1c in T2D patients. Lifestyle education and promotion of salt reduction should be provided to T2D patients.