Association Between Blood Heavy Metal Exposure and Lower Urinary Tract Symptoms in Middle-Aged and Elderly Men:...

The association between cadmium, lead, and mercury exposure and lower urinary tract symptoms (LUTS) in middle-aged and elderly men remains underexplored. This study aimed to investigate the associations and dose-response relationships between blood levels of these heavy metals and the risk of LUTS, and to further examine potential causal links using Mendelian randomization (MR) analysis.

We conducted a cross-sectional study using data from the National Health and Nutrition Examination Survey (NHANES 2005-2008). Weighted multivariable logistic regression models were used to assess associations between serum heavy metals and LUTS. Restricted cubic spline (RCS) analysis evaluated dose-response patterns, and MR analysis was performed to infer causality.

Serum lead levels in Q2-Q4 were significantly associated with increased LUTS risk (OR = 1.54, 95% CI: 1.00-2.36, P = 0.047; OR = 1.67, 95% CI: 1.10-2.54, P = 0.016; OR = 1.58, 95% CI: 1.02-2.44, P = 0.039). Serum mercury in Q4 was also associated with higher LUTS risk (OR = 1.64, P = 0.009), while no significant association was observed for cadmium. RCS analysis suggested linear associations for cadmium, lead, and mercury, and a significant nonlinear U-shaped association for mixed metal exposure. MR analysis supported a potential causal effect of mercury on benign prostatic hyperplasia (OR = 1.54, P = 0.040).

Elevated blood levels of lead and mercury are associated with increased risk of LUTS in men, with mercury possibly exerting a causal influence.