Influence of the type and duration of water intake on blood pressure in hypertensive men

Epidemiological studies have been revealed that there is a relationship between hardness of water and prevalence of CVD. Therefore this study has been planned to determine the influence of local mineral water on blood pressure in hypertensive men. In this cross sectional study, 41 middle age men with hypertension (488) were matched based on age, BMI, WHR, drug, smoking, and duration of the disease and randomly selected in a First and second groups. Respectively, mineral and usual tap waters were given to first and second groups 2 liters per day for 8 weeks. Blood pressures of subjects were calculated by barometer at the 1st, 4th and 8th weeks of experiment. Wilcoxon, Mann-Whiney and t-test were used for statistical analysis of the results. Dietary intakes of subjects were determined by using 24 hours recall questionnaire at the 1st, 4th and 8th weeks of the experiment and were analyzed by Nutritionist III program, which is modified with Iranian Food Data Bank. The mean SBP in first and second groups were after 4 weeks 131.09.98 and 136.18.65 mmHg, respectively. The experiment has showed a significant reduction in 4th week 13.53% in first and 5.64% in second groups (P=0.001). The difference between the groups were statistical significant (P<0.05). SBP reduction in both groups did not show statistical significant after 8th weeks between the groups. The mean DBP in first and second groups were 85.756.34 and 92.624.07 mmHg, respectively after 4th week of experiment with a significant reduction of 11.3% in case and 3% in control groups (P=0.001). Also significant difference in DBP was seen at 4th week of the study between the groups (P<0.05). DBP reduction in both groups did not show statistical significant difference after 8th weeks between the groups. According to the result, mineral spring water has a significant influence on reducing blood pressure after 4 weeks in comparison with tap water, which it could be leading to lower risk of CVD.