Arsenic Exposure-Related Hypertension in Bangladesh and Reduced Circulating Nitric Oxide Bioavailability
Moriom Khatun, Nazmul Haque, Abu Eabrahim Siddique, Abdus S. Wahed, Md. Shofikul Islam, Shuchismita Khan, Ahsanul Mahbub Jubayar, Junayed Sadi, Ehsanul Kabir, Tasnim Tabassum Shila, Zohurul Islam, Md. Khalequzzaman Sarker, Hasan Ul Banna, Shakhawoat Hossain, Daigo Sumi, Zahangir Alam Saud, Aaron Barchowsky, Seiichiro Himeno, Khaled Hossain
Abstract
BACKGROUND: Hypertension is a major cause of death worldwide. Although arsenic exposure has been associated with the risk of hypertension, this association appears nonuniform due to inconsistent results from studies conducted in different populations. Moreover, hypertension is a complex condition with multiple underlying mechanisms and factors. One factor is impaired production and bioavailability of vascular nitric oxide (NO). However, the implications of the effects of arsenic exposure on circulating NO and its association with hypertension in humans are largely unknown. OBJECTIVE: We investigated the dose-response relationship between arsenic exposure and hypertension with vascular NO levels as a potential mediator of arsenic-related hypertension in individuals exposed to a broad range of arsenic. METHODS: . Serum NO levels reflected by total serum nitrite concentrations were measured by immunoassay. A formal causal mediation analysis was used to assess NO as a mediator of the association between arsenic level and hypertension. RESULTS: groups, respectively]. Causal mediation analysis showed a significant mediating effect of NO on arsenic-related SBP, DBP, and hypertension. CONCLUSION: Increasing exposure to arsenic was associated with increasing odds of hypertension. The association was mediated through the reduction of vascular NO bioavailability, suggesting that impaired NO bioavailability was a plausible underlying mechanism of arsenic-induced hypertension in this Bangladeshi population. https://doi.org/10.1289/EHP13018.