Burden of chronic kidney disease from dietary cadmium exposure by educational level in Europe

Background

Cadmium (Cd) exposure is associated with chronic kidney disease (CKD), with diet as the main exposure route in non-smokers. Current estimates of Cd-related CKD burden do not account for socioeconomic differences. This study estimates the CKD burden from dietary exposure to Cd by educational level in five European countries.

Methods

Dietary Cd exposure was estimated using national food consumption data with Cd concentrations in foods or total diet studies, then converted into urinary Cd (UCd) using toxicokinetic modelling. This was combined with an exposure-response function linking UCd to CKD to estimate national-, age-, and education-specific attributable incidence. Disease burden was expressed in disability-adjusted life years (DALYs), combining mortality and morbidity. Estimates were stratified by educational level in five European countries (Belgium, Denmark, France, Portugal, and the Netherlands) and computed using varying toxicological UCd thresholds (0.5 µg/g creatinine as base scenario, 0.3 and 1.0 as sensitivity analyses).

Results

Overall, dietary Cd exposure increased with educational level across countries, except in France, where no significant difference was observed. Mean exposure per education group and country ranged from 0.101 to 0.167 µg/kg bw/day. Under the base scenario, DALY rates ranged from 0.009 (95% Uncertainty Interval (UI): 0.008-0.010) to 0.073 (95% UI: 0.070-0.079) per 100,000 population across countries, with France showing the highest burden and Portugal the lowest. Estimates were highly sensitive to toxicological thresholds, with up to a ten-fold increase at 0.3 µg/g and negligible burden at 1.0 µg/g.

Conclusions

We found that the burden of CKD due to Cd exposure was higher among people with higher levels of education in most countries studied. Results were sensitive to input data; for instance, limited cross-country comparability due to heterogeneous methods used in disease burden and food consumption surveys.

Key messages

• CKD burden rate attributable to dietary Cd exposure generally increases with education level, except in France.

• CKD burden estimates are highly sensitive to toxicological threshold assumptions.