Epidemiological studies have demonstrated that various kinds of urinary element concentrations were different between healthy, prediabetes, and diabetes patients. Meanwhile, many studies have explored the relationship between element concentration and fasting blood glucose (FBG), but the association between joint exposure to co-existing elements and FBG level has not been well understood. The study explored the associations of joint exposure to co-existing urinary elements with FBG level in a crosssectional design. 275 retired elderly people were recruited from Beijing, China. The questionnaire survey was conducted, and biological samples were collected. The generalized linear model (GLM) and twophase Bayesian kernel machine regression (BKMR) model were used to perform in-depth association analysis between urinary elements and FBG. The GLM analysis showed that Zn, Sr, and Cd were signi cantly correlated with the FBG level, under control potential confounding factors. The BKMR analysis demonstrated 8 elements (Zn, Se, Fe, Cr, Ni, Cd, Mn, and Al) had a higher in uence on FBG (Posterior inclusion probabilities >0.1). Further intensive analyses result of the BKMR model indicated that the overall estimated exposure of 8 elements was positively correlated with the FBG level and was statistically signi cant when all element concentrations were at their 65th percentile. Meanwhile, the BKMR analysis showed that Cd and Zn had a statistically signi cant association with FBG levels when other co-existing elements were controlled at different levels (25th, 50th or 75th percentile), respectively.The results of the GLM and BKMR model were inconsistent. The BKMR model could exibly calculate the joint exposure to co-existing elements, evaluate the possible interaction effects and nonlinear correlations. The meaningful conclusions were found that it was di cult to get by traditional methods. This study will provide methodological reference and experimental evidence for the association between joint exposure to co-existing elements and FBG in elderly people.
Materials And Methods
Research Design and Study PopulationA cross-sectional study design was implemented. The retired elderly people (aged above age 60 or more) recruited from the community-based in Beijing, in 2016. This study was approved by the Ethics Committee of the Institute of Basic Medical Sciences, Peking Union Medical College (Beijing, China), and all participants had signed informed consent before the interviews.Personal information was collected using a structured questionnaire through face-to-face communication by the investigator, including gender, age, smoking status, alcohol drinking status, and body mass index (BMI). Medical records were used to gather information on whether the subjects had diabetes and medication use related to blood sugar control.The vein blood (4 mL) was collected from each subject after overnight fasting and used to measure FBG. Blood samples were collected in vacuum tubes containing a thixotropic gel barrier (BD Vacutainer SST II, REF 367...