Effect of water hardness on cardiovascular mortality: an ecological time series approach

Long-Term Consumption of Purified Water Altered Amino Acid, Fatty Acid and Energy Metabolism in Livers of Rats

The consumption of low-mineral water has been increasing worldwide. Drinking low-mineral water is associated with cardiovascular disease, osteopenia, and certain neurodegenerative diseases. However, the specific mechanism remains unclear. The liver metabolic alterations in rats induced by drinking purified water for 3 months were investigated with a metabolomics-based strategy. Compared with the tap water group, 74 metabolites were significantly changed in the purified water group (6 increased and 68 decreased), including 29 amino acids, 11 carbohydrates, 10 fatty acids, 7 short chain fatty acids (SCFAs), and 17 other biomolecules. Eight metabolic pathways were significantly changed, namely aminoacyl-tRNA biosynthesis; nitrogen metabolism; alanine, aspartate and glutamate metabolism; arginine and proline metabolism; histidine metabolism; biosynthesis of unsaturated fatty acids; butanoate metabolism; and glycine, serine and threonine metabolism. These changes suggested that consumption of purified water induced negative nitrogen balance, reduced expression of some polyunsaturated fatty acids and SCFAs, and disturbed energy metabolism in rats. These metabolic disturbances may contribute to low-mineral-water-associated health risks. The health risk of consuming low-mineral water requires attention.

The Relationship between Mortality from Cardiovascular Diseases and Total Drinking Water Hardness: Systematic Review with Meta-Analysis

BACKGROUND

Interest in water chemical activity, its content, and its impact on human health has greatly increased throughout the last decade. Some studies suggest that drinking water with high hardness may have preventative effects on cardiovascular diseases. This study aims to investigate the association between drinking water hardness and cardiovascular disease (CVD) mortality.

METHODS

The study selection process was designed to find the association between drinking water hardness and CVDs mortality. The search included both qualitative and quantitative research and was performed in three databases: Web of Science (Clarivate Analytics, Ann Arbor, MI, USA), PubMed (National Institute of Health, Bethesda, MA, USA), and Scopus (Elsevier, RELX Group plc, London, UK). The project was registered in the International Prospective Register of Systematic Reviews (PROSPERO), registration number: CRD42020213102.

RESULTS

Seventeen studies out of a total of twenty-five studies qualitatively analyzed indicated a significant relation between total water hardness and protection from CVD mortality. The quantitative analysis concluded that high drinking water hardness has a significantly lowering effect on mortality from CVDs, however, the heterogeneity was high.

CONCLUSIONS

This systematic literature review shows that total water hardness could affect CVD prevention and mortality. Due to the many confounding factors in the studies, more research is needed.

Assessment of drinking water safety in the Netherlands using nationwide exposure and mortality data

BACKGROUND

Although drinking water in the Netherlands is generally accepted as safe, public concern about health risks of long-term intake still exist.

OBJECTIVE

The aim was to explore associations between drinking water quality for nitrate, water hardness, calcium and magnesium and causes-of-death as related to cardiovascular diseases amongst which coronary heart disease and colorectal cancer.

METHODS

We used national administrative databases on cause-specific mortality, personal characteristics, residential history, social economic indicators, air quality and drinking water quality for parameters specified by the EU Drinking Water Directive. We put together a cohort of 6,998,623 persons who were at least 30 years old on January 1, 2008 and lived for at least five years on the same address. The average drinking water concentration over 2000-2010 at the production stations were used as exposure indicators. We applied age stratified Cox proportional hazards models.

RESULTS

Magnesium was associated with a reduced risk for mortality due to coronary heart diseases: HR of 0.95 (95% CI: 0.90, 0.99) per 10 mg/L increase. For mortality due to cardiovascular diseases, a 100 mg/L increase in calcium was associated with a HR of 1.08 (95% CI: 1.03, 1.13) and an increase of 2.5 mmol/L of water hardness with a HR of 1.06 (95% CI: 1.01, 1.10). The results show an elevated risk for coronary heart disease mortality at calcium concentrations below 30 mg/L, but over the whole exposure range no exposure response relation was observed. For other combinations of drinking water quality parameters and cause-specific mortality studied, no statistical significant associations were identified.

CONCLUSION

We identified in this explorative study a protective effect of magnesium for the risk of mortality to coronary heart disease. Also we found an increased risk of mortality due to cardiovascular disease associated with the concentration of calcium and the water hardness in drinking water.

Cardiovascular diseases and hard drinking waters: implications from a systematic review with meta-analysis of case-control studies

This systematic review with meta-analysis, performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines, aims at evaluating the potential correlation between magnesium and calcium concentration in drinking waters and the risk of cardiovascular diseases (CVD), which impose a considerable burden in high-income countries. Included studies were of the case-control studies type. From an initial list of 643 potentially eligible articles, seven studies were finally retained in the quantitative analysis. Since each one of them assessed different ion concentrations, subjects exposed to the highest concentration versus those exposed to the lowest concentration were compared. By including an overall figure of 44,000 subjects, the result suggests a protective effect of the ions on CVD prevention, with an effect-size (ES) of 0.82 (95% confidence interval CI = [0.70-0.95], p-value = 0.008) for calcium, and ES = 0.75 (95% CI = [0.66-0.86], p-value = 0.000) for magnesium. Hard water consumption seems to be protective against CVD. However, the high heterogeneity (I² = 75.24, p-value = 0.001 for calcium; I² = 72.96, p-value = 0.0024 for magnesium) and the existence of publication bias limits the robustness and generalizability of these findings. Further high-quality studies are needed to reproduce and confirm these results.

First report on the association of drinking water hardness and endothelial function in children and adolescents

INTRODUCTION

This study aims to investigate the relationship of water hardness and its calcium and magnesium content with endothelial function in a population-based sample of healthy children and adolescents.

MATERIAL AND METHODS

This case-control study was conducted in 2012 among 90 individuals living in two areas with moderate and high water hardness in Isfahan County, Iran. The flow-mediated dilatation (FMD) of the brachial artery and the serum levels of soluble adhesion molecules (sICAM-1, sVCAM-1) were measured as surrogate markers of endothelial function, and high-sensitivity C-reactive protein (hs-CRP), as a marker of inflammation.

RESULTS

Data of 89 participants (51% boys, mean age 14.75 (2.9) years) were complete. Those participants living in the area with high water hardness had higher FMD, hs-CRP, and soluble adhesion molecules (sICAM-1, sVCAM-1) than their counterparts living in the area with moderate water hardness. Multiple linear regression analysis showed that after adjustment for confounding factors of age, gender, body mass index, healthy eating index and physical activity level, total water hardness, as well as water content of calcium and magnesium, had a significant positive relationship with FMD. The corresponding associations were inverse and significant with soluble adhesion molecules (p < 0.05).

CONCLUSIONS

This study, which to the best of our knowledge is the first of its kind in the pediatric age group, suggests that water hardness, as well as its calcium and magnesium content, may have a protective role against early stages of atherosclerosis in children and adolescents.

Serum calcium levels are not associated with coronary heart disease

Background

Numerous studies have reported that low calcium intake is related to a higher prevalence of cardiovascular disease. However, the relationship between serum calcium and coronary heart disease is unclear. The purpose of this study was to compare serum calcium levels in patients with coronary heart disease and those in healthy individuals.

Methods

This retrospective, case-control study conducted in the People’s Republic of China comprised 380 cases and 379 controls. Serum calcium levels, blood lipids, and anthropometric measurements were measured in both groups. The Student’s unpaired t-test or Chi-square test was used to compare differences between cases and controls. Pearson’s partial correlation coefficient was used to determine the association between serum calcium, blood lipids, and blood pressure in both groups.

Results

Our results indicate that the average level of serum calcium in cases was higher than in controls. Serum calcium levels showed no correlation with any parameter except for triglycerides in either group.

Conclusion

Overall, these data suggest that serum calcium has no influence on coronary heart disease or triglyceride levels in the general population.

The relationship between serum calcium level, blood lipids, and blood pressure in hypertensive and normotensive subjects who come from a normal university in east of China

Previous studies revealed that low calcium intake is related to high prevalence of cardiovascular diseases such as hypertension. However, the relationship between serum calcium and blood pressure was unclear. The prevalence of hypertension is high in China. Thus, the aim of this study was to evaluate the serum calcium level between hypertensive and normotensive groups and to investigate the correlation between serum calcium, blood pressure, and blood lipid parameters. A total of 1,135 adult subjects participated in this study and were divide into two study groups: a hypertensive group (n = 316) who had 140 mmHg or higher in systolic blood pressure (SBP) or 90 mmHg or higher in diastolic blood pressure (DBP) and an age- and sex-matched normotensive group (n = 819, 120 mmHg or less SBP and 80 mmHg or less DBP). Our results indicate a significant trend for men (60 years old or older) in the direction of decreasing blood pressure with increasing serum calcium level, but no trend for women was indicated. In the normotensive group, a significant positive correlation was found between DBP and total cholesterol (P < 0.01) and triglyceride (P < 0.01), Likewise, triglyceride was positively correlated with SBP (P < 0.01). Overall, these data suggest that serum calcium may have an influence in the blood pressure of older male subjects with hypertension and in blood lipid profiles of normotensive subjects.