Associations of Urinary Cadmium with Body Composition and Fat Distribution in US Adults: Findings from NHANES 2011-2018.

The effects of cadmium (Cd) on metabolic physiology remain controversial. Given the varying metabolic impacts associated with different body compositions, investigating the relationship between Cd exposure and body composition may facilitate further research. Here, the associations of body composition and fat distribution with urine Cd (UCd) were evaluated. This analysis included 2979 adult participants from the 2011-2018 National Health and Demographic Survey (NHANES). UCd was measured using inductively coupled plasma mass spectrometry and adjusted for urinary creatinine. Body composition and fat distribution were estimated using dual-energy x-ray absorptiometry (DXA). The study results show that UCd was negatively associated with fat mass index (FMI) and percent fat mass (p for trend < 0.001), and the negative correlation between UCd and FMI was stronger in males and smokers (all p for interaction < 0.05). In terms of abdominal fat distribution, UCd was negatively associated with abdominal subcutaneous adipose tissue (SAT) mass (p for trend < 0.001), but with abdominal visceral adipose tissue (VAT) mass only in those with low percent fat mass (< 32.3%) (p for trend = 0.026 and p for interaction < 0.05). UCd was positively related to percent VAT (p for trend < 0.001) and visceral-to-subcutaneous (VAT/SAT) ratio (p for trend = 0.003). And there was a significant negative association between UCd and android-to-gynoid (A/G) ratio (p for trend = 0.001). Meanwhile, UCd was negatively correlated with fat-free mass index (FFMI) (p for trend < 0.001). And the negative correlation between UCd and FFMI was stronger in males, smokers, and individuals with < 32.3 percent fat mass (all p for interaction < 0.05). We found the association of UCd with body composition and fat distribution, with distinct patterns observed in different demographic groups. These findings underscore the importance of considering UCd exposure in the context of body composition and fat distribution.