The impact of dietary sodium, potassium and calcium on blood pressure.

A blood pressure survey was conducted in 3,886 male Taiwanese workers of a single Fukien ethnic group. Their mean age was 34 years. Hypertension defined as a systolic blood pressure of greater than or equal to 140 and/or diastolic blood pressure of greater than or equal to 90 mmHg was present in 370 subjects (9.5%). The high ethnic homogeneity in the study population allowed for an examination on the relationship between diet and blood pressure. A case control study was conducted in 161 subjects with elevated blood pressure and 154 subjects with normal blood pressure, randomly selected in each group, to assess the effects of dietary sodium, potassium and calcium on blood pressure. A 24-hour dietary recall was collected independently by a nutritionist. Using regression analysis, a significant (p less than 0.01) positive association of sodium intake and blood pressure was noted independent of age, body mass index and alcohol intake. The risk of elevated blood pressure was 2.5 times greater in men with a daily sodium intake of greater than 15g compared with those whose daily sodium intake was less than 15g. A negative association of calcium and potassium with blood pressure was noted in a group who ingested potassium greater than 2g and calcium greater than 0.5g daily. However, a statistical significance was achieved for calcium (p less than 0.01) but not for potassium (p = 0.15). These results indicate that dietary sodium and calcium are related to blood pressure and hypertension status within a unique and culturally homogeneous male group of Fukien ethnicity.