Risk factors associated with urinary metal concentrations in middle-aged and older Caribbean adults: the Tobago...

Metal exposures are increasingly recognized as a major risk factor for chronic diseases, yet very few prior studies have comprehensively characterized metal concentrations in the Caribbean.

This study characterized urinary metal concentrations and their associations with demographic characteristics and other lifestyle factors among middle-aged and older Tobagonian adults.

We quantified urinary concentrations of 18 metals and metalloids (referred to here as "metals") in 896 adults from a subsample of the Tobago Health Study, including 466 men and 430 women. Morning spot urine samples were collected from men in 2014-2016, and from women in 2019-2020. Metal concentrations were compared to studies of adults from other populations. Metal exposure risk factors included demographics, body composition, and lifestyle, including diet. We used sex-stratified partial least squares (PLS) regression to identify risk factors associated with metal concentrations.

Twelve metals including arsenic (As), barium (Ba), cadmium (Cd), cobalt (Co), cesium (Cs), copper (Cu), molybdenum (Mo), lead (Pb), tin (Sn), thallium (Tl), uranium (U) and zinc (Zn) were detected in >87% of participants in both men and women. Compared to other populations, Zn and Tl concentrations were higher among Tobagonian men and women. We observed distinct urinary metal concentration patterns among men and women that varied by age, education, body composition and lifestyle factors.

A mix of non-modifiable and modifiable risk factors associated with urinary metal concentrations were identified. These findings can inform future studies to identify vulnerable populations and tailor public health messaging to reduce exposure risk. Future research is needed to understand sex differences and how these exposures may contribute to adverse health outcomes.

This study provides the first comprehensive characterization of urinary metal concentrations among middle-aged and older adults in Tobago, identifying both modifiable and non-modifiable factors associated with exposure. Twelve metals, including arsenic, cadmium, lead, and thallium, were detected in most participants, with some concentrations exceeding those reported in other populations. Distinct urinary metal concentration patterns that varied by demographics and lifestyle factors were observed among men and women. The exposure profiles of adults from Tobago can inform targeted public health strategies and lay the groundwork for future research on the health impacts of metal exposures in this understudied population.