Salinity in Drinking Water and the Risk of (Pre)Eclampsia and Gestational Hypertension in Coastal Bangladesh: A Case-Control Study

Abstract

BackgroundHypertensive disorders in pregnancy are among the leading causes of maternal and perinatal death in low-income countries, but the aetiology remains unclear. We investigated the relationship between salinity in drinking water and the risk of (pre)eclampsia and gestational hypertension in a coastal community.MethodsA population-based case-control study was conducted in Dacope, Bangladesh among 202 pregnant women with (pre)eclampsia or gestational hypertension, enrolled from the community served by the Upazilla Health Complex, Dacope and 1,006 matched controls from the same area. Epidemiological and clinical data were obtained from all participants. Urinary sodium and sodium levels in drinking water were measured. Logistic regression was used to calculate odds ratios, and 95% confidence intervals.FindingsDrinking water sources had exceptionally high sodium levels (mean 516.6 mg/L, S.D 524.2). Women consuming tube-well (groundwater) were at a higher disease risk than rainwater users (p<0.001). Adjusted risks for (pre)eclampsia and gestational hypertension considered together increased in a dose-response manner for increasing sodium concentrations (300.01–600 mg/L, 600.1–900 mg/L, >900.01 mg/L, compared to <300 mg/L) in drinking water (ORs 3.30 [95% CI 2.00–5.51], 4.40 [2.70–7.25] and 5.48 [3.30–9.11] (p-trend<0.001). Significant associations were seen for both (pre)eclampsia and gestational hypertension separately.InterpretationSalinity in drinking water is associated with increased risk of (pre)eclampsia and gestational hypertension in this population. Given that coastal populations in countries such as Bangladesh are confronted with high salinity exposure, which is predicted to further increase as a result of sea level rise and other environmental influences, it is imperative to develop and evaluate affordable approaches to providing water with low salt content.

Saline Drinking Water and Salt in Diet: An Approximate Picture of the Situation in a Coastal Area of Southeastern Bangladesh

“…The central and western coastal areas of Bangladesh are likely to have different conditions of drinking water salinity levels and salt consumption. The quantitative findings of previous studies conducted in the southwest of Bangladesh showed that the sodium levels of drinking water collected from sample ponds and tube wells ranged from 374.3 to 817.0 mg/L, levels that are much higher than the results for the study area presented here (Khan et al 2014;Talukder et al 2017). However, as it was shown in this study, the salinity level changes and enormous effort in monitoring work is required to fully describe the true situation and people's actual exposure profiles.…”

“…As safe salinity levels in drinking water have not been suggested , except that sodium levels greater than 0.2 g/L are unacceptable in terms of taste (WHO 2008), the problem needs attention and the development of emergency countermeasures. In the past decade, studies on the impact of saline drinking water on health in Bangladesh were bolstered (Khan et al 2008(Khan et al , 2014Vineis et al 2011;Rasheed et al 2014Rasheed et al , 2016Talukder et al 2017). Khan et al (2011) studied the influence of saline water on pregnant women living in the coastal zones of Bangladesh.…”

Drinking Water Sodium and Elevated Blood Pressure of Healthy Pregnant Women in Salinity-Affected Coastal Areas

“…All data collection methods are described in more detail elsewhere. 17 Average sodium concentrations per water source were based on 407 available water samples. These samples were collected by the same research group in the dry season of 2010 and 2011.…”

“…16 A recent study in the area reported a dose-response relationship between water sodium concentrations and risk of preeclampsia, a complication of pregnancy characterized by hypertension. 17 Apart from preeclampsia, there are several other adverse outcomes associated with increased blood pressure in Abstract-Coastal areas in Southeast Asia are experiencing high sodium concentrations in drinking water sources that are commonly consumed by local populations. Salinity problems caused by episodic cyclones and subsequent seawater inundations are likely (partly) related to climate change and further exacerbated by changes in upstream river flow and local land-use activities.…”

Salt and Pregnancy Complications: A Proposal for Future Research

“…For example, it is reported that high dietary salt intake increased risk of gestational hypertension and preeclampsia [27][28][29]. Although, Abdoli [30] and Rakova et al [31] proposed that high salt intake can involve in the pathophysiology of miscarriage and preeclampsia through involvement of Th17 cells and their associated inflammatory reactions.…”