Cadmium-Induced Tubular Dysfunction in Type 2 Diabetes: A Population-Based Cross-Sectional Study

Area of Science:

• Environmental Health
• Nephrology
• Toxicology

Background:

• Diabetes and diabetic nephropathy are global health crises.
• Cadmium (Cd) exposure is a known nephrotoxicant, causing kidney tubular dysfunction and reduced eGFR.
• The impact of cadmium on kidney health in diabetic populations remains understudied.

Purpose of the Study:

• To investigate and compare cadmium exposure, kidney function (eGFR), and tubular dysfunction in diabetic versus non-diabetic individuals.
• To determine if diabetes exacerbates cadmium-induced nephrotoxicity.

Main Methods:

• Cross-sectional study in Thailand comparing diabetics (n=81) and non-diabetics (n=593) across low- and high-cadmium exposure areas.
• Measured cadmium and beta-2-microglobulin (β2M) excretion rates normalized to creatinine clearance (Ecd/Ccr and Eβ2M/Ccr).
• Assessed estimated glomerular filtration rate (eGFR) and tubular dysfunction.

Main Results:

• Diabetic individuals showed significantly higher prevalence of tubular dysfunction (8.7-fold) and reduced eGFR (3-fold) compared to non-diabetics.
• Increased cadmium excretion (Ecd/Ccr) was associated with higher odds of reduced eGFR and tubular dysfunction in both groups.
• Even with similar cadmium body burden, age, and BMI, diabetics exhibited more severe tubular dysfunction (higher Eβ2M/Ccr).

Conclusions:

• Diabetes significantly increases susceptibility to cadmium-induced kidney tubular dysfunction and reduced eGFR.
• Diabetic nephropathy may be aggravated by environmental cadmium exposure.
• Public health strategies should consider the combined risks of diabetes and cadmium exposure for kidney health.