Abstract WE450: Association between Multiple Urinary Metals and Metal Mixtures and Ectopic Adiposity in Caribbean Men: The Tobago Health Study

Background: Previous studies reported an association between several urinary metals/metalloids (e.g. arsenic, cadmium, lead) and obesity. However, the majority of studies assessed anthropometrics, only analyzed metals individually, and often had inconclusive results. Hence, there is a need for research on joint metal exposures and ectopic adiposity in the Caribbean, which has one of the fastest-growing rates of obesity and cardiometabolic disorders globally. Objective: This study investigated the associations between arsenic, barium, cadmium, copper, and lead, both individually and jointly, with ectopic adiposity in Afro-Caribbean men. Methodology: This cross-sectional study included 363 Afro-Caribbean men aged 40+, from the Tobago Health Study. Metals were measured from spot urine samples collected between 2014-2016 analyzed by inductively coupled plasma mass spectrometry. Ectopic adiposity was measured via CT scans of the abdomen (visceral and subcutaneous adiposity, psoas and paraspinal muscle density) , and calf. Skeletal muscle density (MD) proxies skeletal muscle adiposity (lower MD reflects more adiposity). Linear regression was used to model individual metal associations with adiposity outcomes, and weighted quantile sum regression was used to measure the mixture of metals with adiposity outcomes. These models were adjusted for age, height, requisite muscle size, total energy and fish intake, urinary creatinine, physical activity, and cardiometabolic disorders (diabetes and hypertension). Results: A higher urinary lead concentration was associated with lower calf(β=-1.23, p=0.0005), and paraspinal(β=-1.72, p=0.002) MD. Higher urinary copper was associated with lower calf MD(β=-1.11, p=0.03), while higher urinary cadmium was associated with lower BMI (β=-1.00, p=0.04), waist circumference (β=-2.72, p=0.04), and calf MD(β=-0.89, p=0.03). The mixture of As, Ba, Cd, Cu, and Pb was jointly associated with lower calf (β=-0.63; CI: -1.12, -0.02) and paraspinal MD (β=-0.80; CI: -1.46, -0.14). There was no association between urinary metals and psoas, visceral, nor subcutaneous adiposity. Discussion: Our findings suggest that individual lead exposure and joint exposure to a mixture of arsenic, barium, cadmium, copper, and lead may be significant risk factors for muscle adiposity and poor cardiometabolic health in African ancestral populations. Additional studies are needed to confirm these findings longitudinally and to identify underlying molecular mechanisms.