Cadmium exposure is associated with reduced grip strength in US adults

BACKGROUND: Muscle strength is a strong predictor of all-cause mortality in the general population. Recent studies have shown an association between environmental pollution and declined grip strength. No previous research has evaluated the specific association between cadmium exposure, a well-known risk factor of several chronic diseases, and muscle strength. METHODS: Cross-sectional study among 4,197 individuals aged ≥40 years, who participated in the National Health and Nutrition Examination Survey (NHANES) 2011-2014, provided data on grip strength, and had either blood or urine cadmium determinations. Grip strength was measured using a Takei digital handgrip dynamometer, and combined grip strength was calculated as the sum of the largest reading from each hand. RESULTS: Median (interquartile range) concentrations of blood (BCd) and creatinine-corrected urine cadmium (Cr-UCd) were 0.32 μg/L (0.20-4.56) and 0.27 μg/g (0.15-0.46), respectively. After adjusting for sociodemographic, anthropometric, health-related behavioral, and clinical risk factors, and serum creatine phosphokinase concentrations, the highest (vs lowest) quartile of BCd was associated with a reduction in combined grip strength of 1.93 kg (95% confidence interval [CI]: -3.51, -0.34), p-trend <0.001. The corresponding values comparing Cr-UCd quartiles 4 vs 1 were -3.24 kg (95% CI: -5.68, -0.79), p-trend <0.001. These results were consistent across socio-demographic and clinical subgroups. CONCLUSIONS: In the US adult population, higher cadmium exposure was associated with decreased grip strength. These results may have important public health implications given the widespread cadmium exposure.