1 Background
Chronic kidney disease (CKD) was defined as an abnormality of kidney structure or function that can adversely affect health1. CKD has become an important public health problem, and is associated with high rates of disability and mortality. In 2016, global years lived with disability among men age 15 to 49 years of age with CKD was 0.81% and deaths were 1.94% 2. The prevalence of CKD (stages 1-5) is estimated to be 3% to 18% globally3, and around 8.6% for adult males and 9.6% for adult females in high-incomes countries4. A cross-sectional survey based on a nationally representative sample of Chinese adults estimated that around 120 million persons have CKD, with a prevalence of CKD of around 11% 5. Persons with CKD have a reduced life expectancy due to increased cardiovascular disease and increased all-cause mortality6. CKD and associated morbidities are important drivers of increased health care costs7. Importantly, in many patients CKD is not diagnosed until it is in a late stage8. Thus, it is important to identify factors that may predict the development of CKD so that early interventions may be given to prevent or delay its development.
The association of glucose metabolism and the development of CKD has been extensively investigated over the past decade. Diabetes is the leading cause of CKD, and up to one-third of adults with newly diagnosed diabetes already have CKD9. Diabetes is thought to be responsible for almost 40% of new cases of CKD10. Pre-diabetes also increases the risk of developing CKD11,12. Diabetes and pre-diabetes diagnosed according to an elevated fasting plasma glucose (FPG) and/or 2-hour oral glucose tolerance test (OGTT) and/or elevated hemoglobin (HbA1c) based on World Health Organization (WHO) 13 or American Diabetes Association (ADA)14 criteria are closely related with the development of CKD. Several studies11,15,16have shown positive associations between CKD and FPG, OGTT, and HbA1c, as well as fasting insulin level, homeostasis model assessment of insulin resistance (HOMA-IR), and HOMA-β. A wide body of evidence supports that abnormalities of glucose metabolism are related with the development if CKD. However, associations have mainly been identified through cross-sectional studies; longitudinal data associating indices of glucose metabolisms and CKD are limited. In addition, few studies have examined if any single index of glucose metabolism is superior for predicting the development of CKD.
Thus, the purpose of this study was to use longitudinal data to investigate associations between glucose metabolism indices and CKD in a Chinese population, and determine which index is superior for predicting CKD.