Dietary trace mineral intake and risk of all-cause and cardiovascular mortality in population with cardiovascular-kidney-metabolic syndrome stage 0–3: a cohort study

Adequate intake of trace minerals may influence mortality risk in individuals with cardiovascular-kidney-metabolic syndrome, although evidence remains limited. We analyzed data from 10,412 participants with CKM stage 0 to 3 from the National Health and Nutrition Examination Survey, 1999 to 2018. Mortality outcomes were ascertained through linkage to the National Death Index through December 31, 2019. Dietary intakes of iron, zinc, copper, and selenium were assessed using 24-hour dietary recalls. Associations between trace mineral intake and mortality were evaluated using Cox proportional hazards models. Nonlinear associations were examined with restricted cubic spline analyses, and two-piecewise Cox proportional hazards models were fitted on either side of the identified inflection points. Over 1,129,579 person-months of follow-up, 1,134 all-cause deaths and 301 cardiovascular disease deaths occurred. Restricted cubic spline analyses showed L-shaped associations between trace mineral intake and all-cause mortality. The inflection points were 13 mg/day for iron, 9 mg/day for zinc, 1.7 mg/day for copper, and 118 µg/day for selenium. Iron and copper intakes were linearly and inversely associated with cardiovascular mortality. Among individuals with intakes below the inflection point, two-piecewise Cox proportional hazards models showed significant inverse associations between all-cause mortality and intakes of iron (HR = 0.94, 95% CI: 0.91–0.97), zinc (HR = 0.95, 95% CI: 0.90–0.99), copper (HR = 0.48, 95% CI: 0.38–0.60), and selenium (HR = 0.99, 95% CI: 0.99–0.99). Subgroup analyses indicated that the association for copper remained consistent across multiple subgroups. Dietary trace mineral intake showed L-shaped associations with all-cause mortality among individuals with CKM stage 0 to 3. Iron and copper intakes were linearly and inversely associated with cardiovascular mortality.