Association between dietary salt and plasma glucose, insulin and hemoglobin A1C 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 glycaemia 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 A1c (HbA1c) 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 was collected through a standardized food frequent questionnaire. Anthropometry, blood pressure and biomarkers were measured by well-trained endocrinology nurses. Generalized linear models (GLM) were used to examine the association. Results A total of 1145 eligible T2D patients with the mean age of 51.4 years were included in the study. Fasting plasma glucose (FPG), 2h postprandial plasma glucose and 2h postprandial insulin, were significantly increased across dietary salt categories. Generalized linear models further showed that dietary salt > 8g/d were positively associated with FPG and HbA1c. Conclusion Higher daily salt intake was found to be associated with FPG and HbA1c in T2D patients. Lifestyle education and promotion on salt reduction should be provided to T2D patients.