Regulating effect of serum selenium on diabetic kidney disease related all-cause mortality: evidence from NHANES database

To explore the interaction between Diabetic kidney disease (DKD) and serum selenium (Se) on mortality from all-cause. Information from the National Health and Nutrition Examination Surveys database (2011-2016) were retrospectively extracted for this cohort study. Associations of DKD and serum Se level with all-cause mortality were evaluated by weighted uni- and multi-variate COX regression analyses, with 95% confidence intervals (CIs) and hazard ratios (HRs). The interaction was measured by attributable proportion of interaction (APAB), relative excess risk due to interaction (RERI), synergy index (S) and 95% CIs. Among 793 adult patients, 98 died from all cause. DKD was linked to an increased all-cause mortality risk [HR = 3.69, 95% CI (1.75-7.81)], while elevated serum Se levels were linked to a decreased all-cause mortality risk [HR = 0.49, 95% CI (0.28-0.86)], after adjusting for co-variables including age, education level, physical activity (PA), CVD, WBC, neutrophil, HB, ALB, and Zn. Additionally, there was a potential antagonistic interaction between DKD and serum Se level on all-cause mortality, with the S value of 0.228. Se may play a protective role in all-cause mortality related to DKD in patients with DM, but this interaction effect needed further exploration.