Albuminuria in People Chronically Exposed to Low-Dose Cadmium Is Linked to Rising Blood Pressure Levels

Area of Science:

• Environmental Health
• Nephrology
• Toxicology

Background:

• Low-dose environmental cadmium (Cd) exposure is linked to increased risks of hypertension and albuminuria.
• The precise mechanisms underlying these associations remain poorly understood.

Purpose of the Study:

• To investigate the causal relationship between cadmium exposure, kidney function decline, blood pressure elevation, and albuminuria.

Main Methods:

• Utilized multiple regression and mediation analyses on data from 641 Thai subjects.
• Normalized cadmium (E_Cd/C_cr), albumin (E_alb/C_cr), and β₂-microglobulin (E_β2M/C_cr) excretion rates to creatinine clearance.
• Assessed risks for chronic kidney disease (CKD) and hypertension per doubling of cadmium body burden.

Main Results:

• Increased risks of CKD (3.52-fold) and hypertension (1.22-fold) were observed per doubling of cadmium body burden.
• Albuminuria risk significantly increased in subjects with hypertension and severe tubular dysfunction.
• Cadmium-induced reduction in estimated glomerular filtration rate (eGFR) causally linked to 80.6% of systolic blood pressure increase, which fully mediated elevated albumin excretion.

Conclusions:

• This study provides the first evidence causally linking cadmium-induced eGFR reduction to elevated blood pressure.
• Elevated blood pressure, driven by cadmium exposure, subsequently enhances albumin excretion, highlighting a critical pathway for kidney damage.