Trace elements in drinking water and the incidence of attention-deficit hyperactivity disorder

TY - JOUR

T1 - Trace elements in drinking water and the incidence of attention-deficit hyperactivity disorder

AU - Thygesen, Malene

AU - Schullehner, Jörg

AU - Hansen, Birgitte

AU - Sigsgaard, Torben

AU - Voutchkova, Denitza D

AU - Kristiansen, Søren Munch

AU - Pedersen, Carsten B

AU - Dalsgaard, Søren

PY - 2021/12

Y1 - 2021/12

N2 - BACKGROUND: Trace elements have been suggested to have neurotoxic effects and increase the risk of neurodevelopmental disorders, but studies of a potential role of trace elements in relation to Attention-Deficit/Hyperactivity Disorder (ADHD) are very limited. The objective of this study was to conduct an exploratory analysis investigating the associations between 17 geogenic trace elements (Ba, Co, Eu, I, Li, Mo, Rb, Re, Rh, Sb, Sc, Se, Si, Sr, Ti, U and Y) found in Danish drinking water and the risk of developing ADHD.METHODS: In this cohort study, 284,309 individuals, born 1994-2007, were followed for incidence of ADHD from the age of five until the end of study, December 31, 2016. We conducted survival analyses, using Poisson regression to estimate incidence rate ratios (IRRs) with 95 % confidence intervals (CI) in three different confounder adjustment scenarios.RESULTS: In a model including adjustments for age, sex, calendar year, parental socio-economic status, neighborhood level socio-economic status and parental psychiatric illness, we found that six of the 17 trace elements (Sr, Rb, Rh, Ti, Sb and Re) were associated with an increased risk of ADHD, whereas two (Ba and I) were inversely associated with ADHD. However, when including region as a covariate in the model, most trace elements were no longer associated with ADHD or the association changed direction. Four trace elements (I, Li, Rb, and Y) remained significantly associated with ADHD but in an inverse direction and for three of these (I, Li and Y), we found significant interactions with region in their association with ADHD.CONCLUSION: The trace elements under investigation, at levels found in Danish drinking water, do not seem to contribute to the development of ADHD and our findings highlight the importance of examining consistency of associations across geographic areas.

AB - BACKGROUND: Trace elements have been suggested to have neurotoxic effects and increase the risk of neurodevelopmental disorders, but studies of a potential role of trace elements in relation to Attention-Deficit/Hyperactivity Disorder (ADHD) are very limited. The objective of this study was to conduct an exploratory analysis investigating the associations between 17 geogenic trace elements (Ba, Co, Eu, I, Li, Mo, Rb, Re, Rh, Sb, Sc, Se, Si, Sr, Ti, U and Y) found in Danish drinking water and the risk of developing ADHD.METHODS: In this cohort study, 284,309 individuals, born 1994-2007, were followed for incidence of ADHD from the age of five until the end of study, December 31, 2016. We conducted survival analyses, using Poisson regression to estimate incidence rate ratios (IRRs) with 95 % confidence intervals (CI) in three different confounder adjustment scenarios.RESULTS: In a model including adjustments for age, sex, calendar year, parental socio-economic status, neighborhood level socio-economic status and parental psychiatric illness, we found that six of the 17 trace elements (Sr, Rb, Rh, Ti, Sb and Re) were associated with an increased risk of ADHD, whereas two (Ba and I) were inversely associated with ADHD. However, when including region as a covariate in the model, most trace elements were no longer associated with ADHD or the association changed direction. Four trace elements (I, Li, Rb, and Y) remained significantly associated with ADHD but in an inverse direction and for three of these (I, Li and Y), we found significant interactions with region in their association with ADHD.CONCLUSION: The trace elements under investigation, at levels found in Danish drinking water, do not seem to contribute to the development of ADHD and our findings highlight the importance of examining consistency of associations across geographic areas.

KW - ADHD

KW - Drinking water

KW - Neurodevelopment

KW - Trace elements

UR - http://www.scopus.com/inward/record.url?scp=85112349335&partnerID=8YFLogxK

U2 - 10.1016/j.jtemb.2021.126828

DO - 10.1016/j.jtemb.2021.126828

M3 - Journal article

C2 - 34391071

SN - 0946-672X

VL - 68

JO - Journal of Trace Elements in Medicine and Biology

JF - Journal of Trace Elements in Medicine and Biology

M1 - 126828

ER -