Background

Arsenic has been associated with hypertension, though it is unclear whether associations persist at the exposure concentrations (e.g. <100 μg/L) in drinking water occurring in parts of the Western United States.

Methods

We assessed associations between arsenic biomarkers and systolic blood pressure (SBP), diastolic blood pressure (DBP), and hypertension in the Strong Heart Family Study, a family-based cohort of American Indians from the Northern plains, Southern plains, and Southwest. We included 1910 participants from three study centers with complete baseline visit data (2001–2003) in the cross-sectional analysis of all three outcomes, and 1453 participants in the prospective analysis of incident hypertension (follow-up 2006–2009). We used generalized estimating equations with exchangeable correlation structure conditional on family membership to estimate the association of arsenic exposure biomarker levels with SBP or DBP (linear regressions) or hypertension prevalence and incidence (Poisson regressions), adjusting for urine creatinine, urine arsenobetaine, and measured confounders.

Results

We observed cross-sectional associations for a two-fold increase in inorganic and methylated urine arsenic species of 0.64 (95% CI: 0.07, 1.35) mm Hg for SBP, 0.49 (95% CI: 0.03, 1.02) mm Hg for DBP, and a prevalence ratio of 1.10 (95% CI: 1.01, 1.21) for hypertension in fully adjusted models. During follow-up, 14% of subjects developed hypertension. We observed non-monotonic relationships between quartiles of arsenic and incident hypertension. Effect estimates were null for incident hypertension with continuous exposure metrics. Stratification by study site revealed elevated associations in Arizona, the site with the highest arsenic levels, while results for Oklahoma and North and South Dakota were largely null. Blood pressure changes with increasing arsenic concentrations were larger for those with diabetes at baseline.

Conclusions

Our results suggest a modest cross-sectional association of arsenic exposure biomarkers with blood pressure, and possible non-linear effects on incident hypertension.

中文翻译：

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强心家族研究中的砷、血压和高血压

背景

砷与高血压有关，但尚不清楚美国西部部分地区饮用水中砷的暴露浓度（例如<100 μg/L）是否仍存在这种关联。

方法

我们在“强心脏家庭研究”中评估了砷生物标志物与收缩压 (SBP)、舒张压 (DBP) 和高血压之间的关联，该研究是一项基于家庭的来自北部平原、南部平原和西南部的美国印第安人队列。我们纳入了来自三个研究中心的 1910 名具有完整基线访视数据（2001-2003 年）的参与者，对所有三种结果进行了横断面分析，并纳入了 1453 名参与者，对高血压事件进行了前瞻性分析（2006-2009 年随访）。我们使用以家庭成员身份为条件的具有可交换相关结构的广义估计方程来估计砷暴露生物标志物水平与 SBP 或 DBP（线性回归）或高血压患病率和发病率（泊松回归）的关联，调整尿肌酐、尿砷甜菜碱，并测量混杂因素。

结果

我们观察到无机砷和甲基化尿砷增加两倍的横断面关联性：SBP 为 0.64 (95% CI: 0.07, 1.35) mm Hg，DBP 为 0.49 (95% CI: 0.03, 1.02) mm Hg，在完全调整的模型中，高血压患病率为 1.10（95% CI：1.01，1.21）。在随访期间，14%的受试者出现高血压。我们观察到砷四分位数与高血压发生率之间的非单调关系。对于具有连续暴露指标的高血压事件，效果估计为零。按研究地点分层显示，砷含量最高的亚利桑那州的关联性较高，而俄克拉荷马州以及北达科他州和南达科他州的结果基本上为零。对于基线糖尿病患者来说，随着砷浓度的增加，血压变化更大。

结论

我们的结果表明砷暴露生物标志物与血压存在适度的横断面关联，并且可能对高血压发生具有非线性影响。