Objective: We examined the association of arsenic in federally regulated community water systems (CWS) and unregulated private wells with type 2 diabetes (T2D) incidence in the Strong Heart Family Study (SHFS), a prospective study of American Indian communities, and the Multi-Ethnic Study of Atherosclerosis (MESA), a prospective study of racially/ethnically diverse urban U.S. communities.
Research Design and Methods: We evaluated N=1,791 participants from SHFS and N=5,777 participants from MESA with water arsenic estimates available and free of T2D at baseline (2001-2003 and 2000-2002, respectively). Participants were followed for incident T2D until 2010 (SHFS) or 2019 (MESA). We used Cox proportional hazards mixed-effects models to account for clustering by family and residential zip code, with adjustment for sex, baseline age, body mass index (BMI), smoking status, and education.
Results: T2D incidence was 24.4 cases per 1,000 person-years (mean follow-up 5.6 years) in SHFS and 11.2 per 1,000 person-years (mean follow-up 6.0 years) in MESA. In a meta-analysis across SHFS and MESA, the hazard ratio (95% confidence interval) per doubling in CWS arsenic was 1.10 (95%CI 1.02, 1.18). The corresponding hazard ratio was 1.09 (0.95, 1.26) in SHFS and 1.10 (1.01, 1.20) in MESA. The corresponding hazard ratio (95%CI) for arsenic in private wells and incident T2D in SHFS was 1.05 (0.95, 1.16). We observed statistical interaction and larger magnitude hazard ratios for participants with BMI <25 kg/m2 and female participants.
Conclusions: Low to moderate water arsenic levels (<10 µg/L) were associated with T2D incidence in the SHFS and MESA.
Funding
This study was supported by NIEHS grants P42ES033719 and P30ES009089, R01ES028758, R01ES032638 and by the NIH Office of the Director and National Institute of Dental & Craniofacial Research (DP5OD031849). Research reported in this publication was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development under grant number P2CHD058486, awarded to the Columbia Population Research Center. Maya Spaur was also supported by NIEHS grant F31ES034284.
The Strong Heart Study has been funded in whole or in part with federal funds from the National Heart, Lung, and Blood Institute, National Institute of Health, Department of Health and Human Services, under contract numbers 75N92019D00027, 75N92019D00028, 75N92019D00029, and 75N92019D00030. The study was previously supported by research grants: R01HL109315, R01HL109301, R01HL109284, R01HL109282, and R01HL109319 and by cooperative agreements: U01HL41642, U01HL41652, U01HL41654, U01HL65520, U01HL65521, R01HL090863, R01ES025216, and R01ES021367. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or the Indian Health Service (IHS) but does represent the views of the U.S. Geological Survey.
The Multi-Ethnic Study of Atherosclerosis (MESA) was supported by contracts 75N92020D00001, HHSN268201500003I, N01-HC-95159, 75N92020D00005, N01-HC-95160, 75N92020D00002, N01-HC-95161, 75N92020D00003, N01-HC-95162, 75N92020D00006, N01-HC-95163, 75N92020D00004, N01-HC-95164, 75N92020D00007, N01-HC-95165, N01-HC-95166, N01-HC-95167, N01-HC-95168 and N01-HC-95169 from the National Heart, Lung, and Blood Institute, and by grants UL1-TR-000040, UL1-TR-001079, and UL1-TR-001420 from the National Center for Advancing Translational Sciences (NCATS). The authors thank the other investigators, the staff, and the participants of the MESA study for their valuable contributions. A full list of participating MESA investigator
